PP1 Veronique Billat Research

The funky Paris neighborhood just north of the Place de la Republique has been known for its canals, crowded streets, excellent African restaurants, and teeming marketplaces, but definitely not for its exercise research. That’s all changed now, because in a small neighbourhood laboratory just a short stroll from the the Jacques Bonsergent Metro stop, a diminutive French scientist named VERONIQUE BILLAT has carried out innovative research which will change the way you train and compete. If you’re a runner, chances are good that Billat’s recommended training programme will shave at least a minute from your IO-K clocking and several minutes from your half-marathon PBs. Endurance cyclists and swimmers can expect similar benefits.

From her small lab at the ‘Centre of Sports Medicine for Electricians and Gas Workers,’ located on the unexpectedly quiet Avenue Richerand, the amiable Veronique has emerged as a rising star in the field of endurance-training research. A competitive athlete herself with a 1:18 PB for the half-marathon, Veronique carries out research which identifies high-quality workouts and optimal long-term training programmes. Above all else, Veronique’s work is always extremely practical: you can literally take her research and run with it. Or cycle. Or swim.

In the past year, Veronique has published a blizzard of new studies on endurance training, but for now we’ll focus on her most recent effort. In that study, Veronique worked with a group of accomplished male runners who were faring pretty well in competitions (running half-marathons in PBs of 70-85 minutes) even though they had been training in a fairly nonsystematic manner. Veronique’s first task was to measure each athlete’s running velocity at V02max, which we’ll call vV02max.

What exactly is it?

Knowing exactly what vV02max represents can be confusing to some runners, so let’s discuss it for a moment. When you run at your marathon pace, you use oxygen at roughly 80 per cent of your maximal possible rate (80% V02max). When you step up to 10-K tempo, you use oxygen at about 90 per cent of your maximal possible rate (90% V02max). At 5-K speed, you’re at 95% V02max. As you accelerate above 5-K velocity, you soon reach a speed at which you’re using oxygen at your maximal possible rate (100% V02max). This speed is your vV02max.

Despite what some runners think, vV02max is in fact not your top speed. To reach your highest velocity during an effort which lasts more than a couple of minutes, you have to use oxygen at your maximal possible rate and produce as much energy anaerobically as you possibly can. This highest speed will be well above vV02max. vV02max is simply the first running speed above 5-K pace which corresponds with your maximal rate of oxygen use (V02max).

As we explained in the November issue of PEAK PERFORMANCE, V02max can be a pretty lousy predictor of performance potential when you try to compare various runners. However, vV02max is an outstanding predictor, mainly because it combines aerobic capacity (the total amount of oxygen a runner can use) and running economy (how efficiently oxygen is used). Looking at vV02max is rather like examining how big a runner’s ‘petrol tank’ is and how efficiently he/she uses what’s in the tank. vV02max doesn’t apply only to runners, however. There’s also a cycling vV02max (the cycling speed at which a cyclist reaches V02max), a swimming vV02max, a stair-machine vV02max, and so on.

If you’re a runner, you can determine your own vV02max on your friendly neighborhood track. In fact, you must work out your vV02max to train according to Veronique Billat’s new system. We provided full details on calculating your velocity at V02max in the November issue; for a short summary of that technique, please see the accompanying box.

Calculating your TvV02max

The next step Veronique took in her research will be your next step, too. You must figure out how long you can actually run at your vV02max. Don’t do this on the same day that you determine your vV02max, however. In fact, to get an accurate reading, you should rest - training lightly or not at all - for a couple of days first. You must also obtain your doctor’s permission before trying the following test.

To find out how long you can actually run at vV02max, warm up by jogging easily on a track for 10 minutes, and then begin running at your precise vV02max. If your vV02max corresponds with six-minute per mile pace, for example, you should be running each 400-metre lap in about 90 seconds. Have a friend call out splits to you every 100-200 metres or so to make sure that you’re at exactly the right tempo. Time yourself over your total effort (not counting the warm-up), and keep running as long as you can. When you can no longer continue running at vV02max, stop the watch and determine the total time you were able to run at vV02max (be honest; you know you’re not really running at vV02max any longer if you’re more than five-metres short on a 200-metre lap or 10-metres shy over 400 metres). The total time you’re able to run at vV02max is your TvVO2max.

In the old days, exercise physiologists used to say that your vV02max was the fastest pace you could sustain continuously for about 11-12 minutes. In other words, TvVO2max was considered to be an mlmutable 11-12 minutes, but Veronique’s work has changed that outdated thinking. The ingenious Billat has shown that in fact some runners, cyclists, and swimmers can sizzle along at vV02max for no more than about three minutes or so, while others have a TvVO2max of 13 minutes! It’s an individual thing, but the bottom line is that you must know both your vV02max and TvVO2max if you want to train according to the principles of Billat’s programme.

Here’s the schedule to follow

Once you know your vV02max and TvVO2max, you’re ready to begin Veronique’s schedule. Fortunately, it is easy to carry out, and it pays big dividends. Even though they were already accomplished runners when they began to work with Veronique, individuals who trained according to her system were able to trim their half-marathon times by 5-7 per cent (four to six minutes) over a seven-month time period! Here’s Veronique’s actual schedule:

MONDAY Run for about one hour at 70% vV02max. What could be simpler? Let’s say you’ve discovered that your vV02max is six-minute per mile pace. That’s a velocity of 1609 metres per mile divided by six minutes per mile = 268 metres per minute. 70 per cent of that is 188 metres per minute. 1609/188 = 8.56 minutes per mile, or 8:34 tempo. You would run for one hour at 8:34 per mile.

TUESDAY This is the only time in the week when things get slightly complex. Tuesday is interval-training day, which in Veronique’s scheme of things means that on the first week of your training period you run your intervals at exactly vV02max. How long should these work intervals last? ‘Exactly half the amount of time you can actually run at vV02max,’ says Veronique. In other words, if your TvVO2max is eight minutes, your work intervals will last for four minutes. You complete five of these work intervals per workout, and your recoveries last the same amount of time as the work intervals, but your recovery speed will be 60 per cent of your vV02max (see the description of Monday’s workout to find how to calculate 60% vV02max).

All right so far? Fine, because on the second Tuesday of the overall programme, you’ll make a slight adjustment. This time, you’ll run your work intervals at only 95% vV02max, but they’ll each last for 60 per cent of TvVO2max (each interval is slightly longer). Again, carry out five work intervals per workout, let your recoveries last exactly as long as your work intervals, and run the recoveries at 60% vV02max.

On the third Tuesday, there’s yet another wrinkle. This time, you uncork a bit of your real leg speed which has been dormant for so long and sizzle through your work intervals at 105% vV02max. If your vV02max is 300 metres per minute for example, you would run these 105%-vVO2max intervals 5-per cent faster - at 315 metres per minute,or 1609/315=5:06 per mile pace. Each work interval lasts for 40 per cent of your TvVO2max, the recovery intervals are just as long, and your recovery speed is again 60% vV02max. Oh yes - you must run a total of five work intervals during the workout.

On the fourth Tuesday, you get a bit of a break. After all, you’ve been working hard, so it’s time to recover a bit. Simply run easily for one hour at 65% vV02max. On the fifth Tuesday, revert back to the first Tuesday of the overall schedule and complete that workout, on the sixth Tuesday do the second Tuesday’s session, and so on. The Tuesday workouts, like the Thursday sessions, are on a four-week cycle.
WEDNESDAY Back to an unvarying routine: simply jog for about 75 minutes at 65% vV02max.

THURSDAY Things get slightly more complicated again. On the first Thursday, complete four 10-minute intervals at a new intensity - 80% vV02max, with five-minute jog recoveries in between.

On the second Thursday, carry out three 15-minute intervals at 80% vV02max, again with five-minute jog recoveries.

On the third Thursday, conduct two 20-minute intervals at 80% vV02max, with five minutes of easy jogging in between.

On the fourth Thursday, you have it made: just rest (if ‘rest’ is a foreign word to you, it means absolutely no running at all!). Obviously, the Thursday sessions (not counting the fourth one) are Veronique’s versions of traditional tempo workouts.

FRIDAY Take a rest day, and don’t run at all. It’s okay to do some stretching and a bit of strength training if you want to, however.

SATURDAY Run for around 90 minutes at 70% vV02max.

SUNDAY Free running. Run for fun, and don’t push the pace too much. The important thing is to keep moving for two hours.

To summarize the overall training programme, you first figure your vV02max, then your TvVO2max, and you then begin training a la Veronique, with the schedule outlined above. If you respond to training as Veronique’s runners did, your TvVO2max will improve significantly after eight weeks, and your vV02max will be better after no more than 12-16 weeks. Within 8-12 weeks, you should be establishing better race times at distances from 5000 metres up to the half-marathon.

If you’re a cyclist or swimmer, how do you estimate your vV02max? Easy! Just cycle or swim as far as you possibly can in 15 minutes, then figure your actual pace in metres per minute (or feet per minute if you’re still in the old school of distance measurements). Increase that pace by 5-6 per cent, and you should be very close to vV02max. You can then use the intensities above to construct a training programme.

Evaluate thyself

Since you’ll be improving as the programme proceeds, it’s important to evaluate yourself every eight weeks. The best way to do this is to reserve a Saturday at the end of each eight-week period to re-calibrate your vV02max (do the vV02max test instead of your normal Saturday workout). On the following Monday, compute your TvV02max instead of the regular Monday workout. After you know your new vV02max and TvV02max, adjust your workout speeds accordingly.

If you’re a relatively new runner and can’t yet run for one hour at a time, gradually increase the frequency and distance of your training runs until you feel comfortable training six days a week and can run for 7590 minutes in a single workout. Then, begin Veronique’s programme. Bear in mind that the overall schedule is not etched in stone; if you feel fatigued on a particular day, it’s okay to skip that day’s workout. However, it’s preferable if the key workouts on Tuesdays and Thursdays are not missed.

Veronique’s new training programme is straightforward and easy to carry out once you become used to it. It’s beautifully constructed, with special Tuesday sessions to heighten vV02max and TvVO2max and Thursday efforts to boost lactate threshold running speed. In line with current research, it also features a very good rest and recovery period every fourth week.

‘Carrying out excellent training is not hard to do,’ says Veronique. ‘You simply have to have reliable reference points around which to structure your workouts.’ Those dependable points happen to be your vV02max and TvVO2max. Once you know them, you can train systematically in a way that should trim large chunks of time from your current PBs.

Owen Anderson

PP2 New vVO2max workouts lead to impressive gains in fitness

PP3

Fitness For Football: Endurance training boosts performance in the field

Football players need a combination of technical, tactical and physical skills in order to succeed. It is odd, therefore, that football research has tended to focus on technique and tactics, with little emphasis on how to develop the endurance and speed needed to become a better player.
In one of the few studies which has explored the link between endurance capacity and football performance, Hungarian researchers showed that the ranking among the four best teams in the Hungarian top division was reflected by their players’ average maximal oxygen-uptake (VO2max) values(1). Another investigation found a significant correlation between VO2max and the distance covered by players during matches, the number of sprints per match and the frequency of participation in ‘decisive situations’(2).

Some studies have also shown that footballers tend to cover less distance and work at lower intensities during the second half of games than during the first half. The logical interpretation of these findings is that fatigue is limiting the players and that if they were fitter they would perform more effectively in the latter stages of their matches. None the less, until now no investigation has clearly shown that improving aerobic capacity and overall fitness boosts performance on the football field.

Fortunately, that deficiency has now been remedied, thanks to the work of Jan Helgerud and his colleagues at the Norwegian University of Science and Technology in Trondheim(3). Their new study involved 19 male players from two Norwegian junior lite teams - ‘Nardo’ and ‘Strindheim’ - all of whom had been playing football for at least eight years. Both teams had been among the most successful in Norway over the past five years and six of the participants were members of the Norwegian national junior team. The players had an average age of 18 and mean mass of 72kg (158lb).

Aerobic interval training v extra technical training

Players within each team were randomly assigned to either a training group or a control group, so that each team had members in both groups. In addition to their regular football training and play (four 90-minute practices and one game per week), members of the training group performed aerobic interval training twice a week for eight weeks. Each interval workout consisted of four discrete four-minute work intervals at 90-95% of maximal heart rate, with three-minute recoveries at 50-60% of max heart rate. Technical and tactical skills, strength and sprint training were emphasised in most practice sessions, and about one hour of each practice was devoted to mock football games. While the training group members carried out their four-minute intervals, control soccer players engaged in extra technical training, including heading drills, free kicks and drills related to receiving the ball and changing direction.

At the beginning and end of the eight-week study period, all players were tested for VO2max, lactate threshold, vertical jumping height, 40m sprint ability, maximal kicking velocity and the technical ability to kick a football through defined targets.

After eight weeks of twice-weekly interval training, the players in the training group had improved VO2max by almost 11%, from 58.1 to 64.3 ml.kg-1.min-1; meanwhile control group players had not upgraded VO2max at all! Similarly, lactate-threshold running speed improved by 21% and running economy by 6.7% in the training group, while controls again failed to improve at all. Clearly the players in the training group were gaining tremendous physiological benefits from just two aerobic workouts per week!

Happily, all of these physiological details translated into some markedly improved performances on the football field: interval-trained athletes increased the total distance covered during games by 20% (from 8,619 to 10,335m) and also doubled the number of times they sprinted during games (a sprint being defined as an all-out run lasting at least two seconds). Furthermore, after eight weeks of interval training the number of involvements with the ball per game increased by 24%, from 47 to 59. (Involvements were defined as situations in which a player was either in physical contact with the ball or applying direct pressure to an opponent in possession of the ball.)

Interval training also boosted the athletes’ overall ability to play at high intensity; after eight weeks of interval work, they were able to perform at an average of 85.6% of max heart rate during their games, compared with just 82.7% beforehand. Training group members also spent 19 minutes longer than controls in the high-intensity zone (ie above 90% of max heart rate) during an actual game.
Of course, interval training isn’t a panacea, and sprint speed, squatting strength, bench-press strength, jumping height, kicking velocity and the technical shooting and passing test were unchanged by the aerobic work, as you might expect.

None the less, this very simple interval training programme (with just two workouts per week and four 4-minute intervals @ 90-95% of max heart-rate per workout) produced some dramatic improvements in overall play. Put simply, boosting VO2max, lactate threshold and running economy with interval routines gave the players an enhanced ability to cover longer running distances at higher intensities during games and to be involved with the ball more frequently and thus play a greater role in deciding the outcomes of competitions.

No footballer can argue that he/she does not have enough time for such additional training, which should be included in all overall programmes. Interestingly enough, the VO2max ultimately attained by the interval-trained players (64.3 ml.kg-1.min-1) is above the average VO2max reported for experienced international footballers, suggesting that a large number of football players could benefit from aerobic training.
Athletes in many other disciplines which are not traditionally viewed as endurance sports might also benefit from the kind of interval training carried out by the Norwegian football players. In particular, interval work should offer advantages for those involved in rugby and basketball.

Recent research carried out at the Victoria University of Technology in Australia revealed that basketball places huge demands on the cardiovascular system, suggesting that aerobic capacity improvements might upgrade the quality of play(4). In this study, eight players (three guards and five forwards or centres) from the Australian National Basketball League were monitored during league competition and practice games. Each competition consisted of four 12-minute quarters, with a 15-minute break at half time and two-minute breaks between quarters. Maximal aerobic capacity (VO2max) was determined for each player.
When the ball was in play, there was a change in movement category (for example, from medium-intensity shuffling to sprinting) every two seconds, and ‘very intense’ activity accounted for almost 30% of court time. This translated into a heavy load on the players’ cardiovascular systems, with heart rate during play averaging 89% (compared with 86% of max for the interval-trained Norwegian football players and 83% for the Norwegian controls). Basketball players’ heart rates were above 85% of max for at least 75% of court time. Even more impressively, cardiac beating was in the 95-100% of max range for 15% of court time and in the 90-95% range for 35% of total time. During free-throw shooting, heart rates recovered to around 70-75% of max.

Interestingly, blood-lactate levels were also quite high in the basketball players, with average lactate concentration at 6.8 millimolars (mM)/litre. Somewhat surprisingly, lactate levels as high as 13 mM/litre were recorded in some of the athletes, comparable to those seen in top-level sprinters after 400m races. These findings suggest that lactate-threshold improvement might benefit basketball players’ performances.
Overall, there were about 105 ‘high-intensity’ efforts per player per basketball game, and each such exertion (whether it involved fast running or intense side-to-side shuffling) lasted for about 14 seconds. Thus, a basketball game was a bit like carrying out an interval workout with 105 14-second reps. Recoveries between repetitions were short, since intense efforts occurred every 21 seconds.
As it turned out, the Australian basketball players had average VO2max readings of 61 ml.kg-1.min-1, compared with 64.3 in the interval-trained football players and 59.5 in the control group. This suggests not only that basketball itself boosts VO2max but also that improvements in VO2max might foster better play, just as it does in football.

What other interval workouts besides the Norwegians’ 4×4-minute scheme might be beneficial for football and basketball enthusiasts? Clearly, some of the renowned French scientist Veronique Billat’s ‘v VO2max’ sessions would be helpful, since they are very intense in nature and lead to enhancements in VO2max, lactate threshold, and running economy.

Two of Veronique’s workouts should be particularly beneficial:

l The 30-30. To perform this workout, athletes should simply warm up effectively, then alternate 30 seconds of running at close to max intensity with 30 seconds of easy ambling. Initially, they should go for 10 reps, but as aerobic capacity improves they can simply keep going until fatigue kicks in;
l The 3-3. This is like 30-30, except that athletes alternate three minutes of hard running with three minutes of loping. The pace for the strenuous three-minute intervals should be determined by the best-possible speed achieved during a six-minute test. (Naturally, ‘re-tests’ of six-minute velocity will be needed every 4-6 weeks-or-so, since running capacity should improve.) Few athletes should try to complete more than five three-minute intervals per workout.

What’s the bottom line? In several key ways, football and basketball count as ‘endurance sports’, since they place a high demand on the cardiovascular system, and since performance ability appears to hinge on physiological variables such as VO2max, lactate threshold and running economy. Thus, performing the types of interval workouts used by endurance athletes should be helpful to players of both sports.

Owen Anderson

References

Science and Football, T Reilly, A Lees, K Davids, and WJ Murphy (Eds). London: E & F N Spon, 1988, pp 95-107

2. Proceedings of the 1st International Congress on Sports Medicine Applied to Football, Rome, 1980, L Vecchiet (Ed) Rome: D Guanillo, 1980, pp 795-801

3. Medicine and Science in Sports and Exercise, vol 33(11), pp 1925-1931, 2001

4. Running Research News, vol 12-3, pp 11-12, 1996

PP4 Interval Training: How to strike and sustain VO2max gold, and other benefits of high-quality workouts

Cyclists, swimmers, rowers, cross-country skiers, orienteers, triathletes and runners all engage in interval training in order to increase the amount of time they spend exercising at very high intensities. A runner scampering along without stopping at his/her current best 10k velocity might be able to sustain the pace for only 25 minutes-or-so during a workout; by breaking the effort down into eight-minute intervals, however, the same runner could often work at 10k velocity for a total of 32 minutes (four eight-minute intervals), thus boosting the ‘quality’ of the session (the time spent above lactate-threshold velocity) by 28%.

Although critics carp that interval sessions are unrealistic and not specific to competition (few races feature the recovery periods which are characteristic of interval workouts), one can find little fault with the way they enhance the quality of training. Training at intensities above 90% VO2max is one of the most potent routes to fitness, and intervals allow athletes to enter this ‘red-line’ training zone consistently and productively - for augmented periods of time.

There is some debate about the origins of interval work, but it’s likely that the Finnish runner Hannes Kolehmainen was the first elite athlete to employ intervals consistently within a comprehensive training program. Kolehmainen, an Olympic gold-medal winner in 1912, liked to perform intervals at race pace, and was known to use a workout consisting of 5-10 repetitions of 3:05 per 1000m - a tempo of 74 seconds per 400m, or 19.5k/hour, which was very close to his 10k race speed (1). Training at race pace has remained a useful tool for athletes in a variety of sports; it is believed to enhance metabolic efficiency and boost mental confidence at race-specific velocities.

Another great Finnish runner, Paavo Nurmi, who captured four gold medals at the 1924 Olympics and once set three world records within a 90-minute time span, pioneered the practice of using higher-than-competitive intensities during interval workouts. The sturdy Nurmi, who dominated distance running in the 1920s, ran 5000m in 14:36, or 70 seconds per 400m. (It’s interesting to note that at that pace he would be over 700m shy of the finish line when the current world record-holder crossed the tape.) But he liked to reel off a succession of 400m intervals in 60 seconds each within the overall context of a 10-20k run on wooded trails (op cit). A few simple calculations reveal that, at 60-second per 400m pace (6.67m per second) Nurmi was running about 14% faster than his 5k race tempo at almost 110 percent vVO2max, an intensity still favoured by endurance athletes seeking to improve their maximal cycling, swimming, rowing, skiing or running speeds.

About 15 years after Nurmi was in his prime, a tree trimmer from Sweden began to employ a new form of interval training with great success. Gunder Hagg liked to alternate hard intervals of speedy running with periods of easy coasting along the forested trails of central Sweden. Coached by Gosse Holmer, the ‘father’ of fartlek training, Hagg liked to complete at least 10k of fartlek intervals per day (often broken down into two 5k ‘pieces’), and the speedy work paid off: Gunder set ten world records at seven distances during 1942 (2).

Zatopek’s amazing 100 x 400m reps

In spite of the great success of Kolehmainen, Nurmi, and Hagg, interval training didn’t really take off until after World War II, and it was not a Finn but a notable Czechoslovakian athlete, Emil Zatopek, who perhaps did the best job of convincing the athletic world at large that intervals represented an unparalleled training technique. Zatopek used a somewhat unusual interval combination: he ran relatively short repeats, often no more than 400m in length, but instead of blazing through these relatively short interval distances at high speeds, he ran them at close to his lactate-threshold velocity, ie well below both 10k and 5k race speeds (3).

The hard-working Czech was known to rattle off 100(!) of these 400m reps per day, alternated with 200m recoveries. Scientists later reckoned (op cit) that Zatopek reached lactate-threshold speed at about 85% of his vVO2max (ie at a pace of about 72 seconds per 400m), which meant that on a 100-work-interval day he was completing about 40k of work intervals in just 120 minutes or so. (Before you become completely incredulous, don’t forget that there were 39 ‘recoveries’ injected into such running to make the 100 x 400 scheme more palatable.) Zatopek’s pattern of churning out high volumes of moderate-quality (below 90% VO2max) training was echoed, albeit on a less grandiose scale, by the American runner Jim Ryun in the late 1960s and early 1970s.

Interval training made its way into a scientific journal for the first time in 1959, when German exercise scientist H Reindell and colleagues described specific interval training carried out by top athletes and formulated some basic rules for interval work (4,5). Sigfried Hermann, an athlete described in Reindell’s book, specialised neither in Zatopek’s ‘large bag’ of slow intervals or Nurmi’s ’short stack’ of scalding reps; he engaged in what could be called ‘variable-pace’ interval training. A 3:40 1500m runner, Hermann would - within a single workout - run four sets of 6 x 200m, with rests of 50-60 seconds between the 200m work intervals and eight minutes between sets. Sigfried completed the first set at a tempo of 30 seconds per 200 (or 98% of 1500m speed), the next two sets at almost-exact 1500m race velocity, and most of the final set at 28 seconds per 200 (about 105% of 1500m race tempo). The German whizzed through the very last interval of the last set in 25 seconds, which was 118% of his race velocity over 1500m.

This variable-pace interval training, performed above and below actual race velocity, was mirrored in the early 1980s by famed British coach Frank Horwill, the founder of the British Milers’ Club and mentor of two-time World Cross Country silver medallist Tim Hutchings. Horwill, however, liked to use the different paces on separate days of training, a scheme he called ‘multi-paced training’. Peter Coe later based Seb Coe’s overall training on Horwill’s multi-speed foundation. Variably-paced intervals were also employed with great success in the 1980s by Said Aouita of Morocco, who held world records for both the 1500 and 5000m and ran at speeds ranging from lactate-threshold velocity all the way up to 1500m competition speed within the same session, with interval distances ranging from 200-3000m.

Broad-intensity training builds speed and stamina

This ‘broad-intensity’ (ie variable-pace or multi-paced) interval training has become increasingly appealing, mostly because it is believed to build both speed and stamina, but also because it is known that athletes seldom move at a constant pace during their competitions, even during world-record efforts. Indeed, French scientists Veronique Billat and Jean-Pierre Koralsztein have shown that top performances in distance races actually consist of series of ‘wavelets’ - regular, well-defined periods of high intensity alternated with sequences of lower overall power (6). In theory, to enhance efficiency over the range of paces employed over a single race distance, one would have to ‘rehearse’ the tempos properly during training, a process most conveniently carried out during an interval workout.

Exercise scientists have, of course, tried to determine which work interval intensities, work interval durations and recovery durations are best for optimising fitness. This work began in earnest in the early 1960s, thanks to the efforts of Per Olof Astrand of Sweden. Working at the famed Karolinska Institute in Stockholm, Astrand developed what he called ‘long’ interval training, with work intervals lasting for three minutes at intensities of around 90-92% vVO2max and complete rest between intervals. In spite of the very easy recoveries and submaximal intensities, Astrand’s athletes were able to ‘hit’ VO2max itself during the last repetitions of the overall workout, an event which excited Astrand considerably.

The Swede suggested that his three-minute interval workout represented one of the very best forms of training to improve VO2max, since cardiorespiratory parameters (cardiac output, stroke volume, and oxygen consumption rate) reached their maximums during the session (7). That principle - that intervals should be contrived to ensure the attainment of VO2max - remains firmly entrenched and is practically unassailable from a logical standpoint. However, today’s exercise scientists and up-to-date coaches judge the value of interval workouts not just by whether VO2max is attained but also by how long it is sustained within the session.

At about the same time that Per Olof was carrying out his investigations, his colleague E H Christensen proposed a quite different form of interval training - 10-second work intervals at the higher intensity of vVO2max itself, with 10 seconds of complete rest for recoveries. Somewhat surprisingly (given the short duration of the work intervals), the rate of oxygen con-sumption also ’struck’ VO2max toward the end of this workout, and blood-lactate accumulations were low, which was believed to be a good thing (8). It was thought at the time that low lactate levels would be linked with low levels of fatigue, thus ensuring that an interval workout could be continued for a substantial period of time. Today we know that lactate does not cause fatigue and that high concentrations of lactate are sometimes desirable, since they stimulate muscle cells to ‘learn’ how to clear lactate from the blood, an effect which improves lactate threshold.

Christensen’s group probed deeply into the effects of work interval duration on workout quality, particularly during rather short work intervals (op cit). They found that when athletes alternated 15 seconds of work at vVO2max with 15 seconds of complete recovery it was possible to sustain exercise for at least 30 minutes, with VO2max again being attained toward the end of the session and lactate levels remaining low (at just 2.3 mmol/litre). When recovery intervals dropped to 10 seconds (in conjunction with the 15-second work intervals), lactate levels began to mount (reaching 5-6 mmol/L), since muscles were getting less chance to ‘make lactate disappear.’ However, when both work and recovery intervals were pared down to five seconds, blood lactate dropped back to 2.5 mmol/L, and athletes reached only 81% of VO2max during the workout, despite the fact that they were running at the same speed used during the 10 and 15-second intervals. It was clear that the five-second work intervals were not long enough to significantly stoke either oxygen consumption or lactate production.

When longer work intervals are better

Later studies showed that when work interval intensities were pulled below the vVO2max preferred by the Christensen-Hedman-Saltin team, the total load on the cardiorespiratory system could usually be directly related to the length of the work interval. For example, when the Astrand-Christensen group analysed work intervals of 30 seconds, one minute, two minutes, and three minutes - all carried out at moderately high but not vVO2max intensities - they found that the shortest work intervals produced a submaximal load on the circulatory and respiratory systems (just 63% of VO2max) as well as low lactate levels (2 mmol/L). By contrast, the two and three-minute intervals eventually tipped VO2max to 100% (even though each interval by itself was not as ‘hot’ as vVO2max) and caused blood lactate to soar to 16.6 mmol/L. Naturally, the authors recommended that athletes should selectively use the longer intervals whenever work-interval intensity was below vVO2max (9).

What made the longer intervals better? Basically, Astrand and another noted Swedish exercise physiologist, Bengt Saltin, determined that when an athlete is moving along at below vVO2max but above about 90% vVO2max it usually takes him/her about two minutes to reach VO2max during the first work interval of a training session (10). When this intensity zone is used, he/she would tend to fall short of VO2max during the first work interval of his/her training session if he/she employed 30 to 60-second work intervals. Interestingly enough, the subsequent 30-second (or one-minute) recovery intervals might knock oxygen consumption down so appreciably that it would be difficult to attain VO2max over the course of the workout. On the other hand, if an athlete extended the work intervals to three minutes, VO2max would be attained during the first work interval, and oxygen consumption would be so high that the subsequent recovery intervals would have less opportunity to depress oxygen usage during follow-up work intervals. In practice, VO2max was usually reached in less than two minutes during ‘later’ work intervals within the overall session.

If long intervals are ‘good’ and short intervals ‘bad’, why did Astrand’s original patterns of 10-10 (10 seconds of work and 10 seconds of recovery) and also 15-15 allow for the attainment of VO2max? The answer is that the work interval intensities were - at vVO2max itself - higher, and the recovery intervals short enough (15 seconds or less) to ensure that that oxygen consumption rates didn’t dip too far during recovery, allowing consumption to climb slowly but steadily towards VO2max in the course of the workout. As you have certainly guessed by now, VO2max is more likely to be reached within an interval workout when work intervals are intensified and recovery intervals abbreviated.

Are there times, though, when recovery intervals should ‘go the other way’, ie be longer than the corresponding work interval? There are a couple of key arguments in support of this idea. First, coaches rightly point out that when recovery intervals are kept short, work interval quality tends to erode over the course of a workout as fatigue levels mount, with the final intervals of the session often several seconds slower than planned pace. Practising slow-downs is sub-optimal, the argument goes, and therefore it would be better to take longer recoveries in order to ensure that each work interval is of the highest-possible quality. Secondly, some coaches and exercise experts argue that if athletes want to improve their economy, they should carry out their work intervals with the most efficient motor units within their muscles. Trimming recovery, these coaches suggest, ensures that the most energy-efficient motor units will be fatigued and non-functional late in the workout, thus leading to a situation in which sub-optimal motor units are being trained.

Why not train sub-optimal motor units?

Let’s address this second argument first. Believe it or not, there is some fatigue associated with racing, and if efficient motor units are threatened by an interval workout they will be in much more trouble in a racing situation, which ultimately means that the sub-optimal motor units will be called into play to save the day. So why not train those sub-optimal units?

We should point out, too, that although the existence of super-efficient motor units is plausible, they have never actually been identified in scientific research, nor has there been any verification that these super collections of cells tend to fatigue before their less efficient colleagues. This being true, it seems there’s no need to worry too much about the save-the-efficient-unit argument.

On the other hand, losing work interval quality is something to fret about. If your planned workout calls for you to cycle four 5000m repeats on your bike in six minutes each, for example, and this training tempo is a reasonable one for you, but your second interval comes off in 6:10, your third in 6:20, and your fourth in 6:35, you’ll need to make some adjustments. If you were just having a bad day, you wouldn’t worry about it, but if you were rested and feeling OK before the session, then it would be a good idea to expand the recoveries to make the work intervals more feasible. It’s possible that you simply bit off more than you could chew, with recoveries that were too short to start with. If you decided on two-minute recoveries, you were probably being over-ambitious and would be advised to begin with equal recoveries, even if the idea of six minutes of lazy cycling between work reps is somewhat abhorrent. You could then start carving away at the recoveries and keep reducing them until it’s no longer possible to pull off the workout.

In the case outlined above and in similar situations, would you ever use recoveries which were longer than the work intervals? For example, if you were running very fast 400s on the track, would it make sense to take long recoveries in order to boost the prospects of hitting really good 400s? Some coaches recommend recovery/work ratios as high as 5:1 (five minutes of recovery for each minute of work) in a bid to make work intervals more productive.

Keep recoveries short to boost VO2max

If you are an endurance athlete perplexed about what to do, simply remember that if you are trying to improve VO2max, vVO2max and/or lactate threshold, you should attempt to keep recovery intervals as short as you reasonably can. Lengthening recoveries will tend to drive down average oxygen-consumption rates and mean levels of lactate production, effects which are counterproductive in terms of VO2max and lactate-threshold.

Let’s say, for example, that a distance runner named Ben is doing a classic interval workout,10 x 400m, and has chosen to carry out the session at a goal 5k race tempo which is four seconds per 400m faster than his current 5k pace. Since his 5k pace is 75 seconds per 400m, his interval pace will be 71 seconds per 400m. That’s very reasonable, but should he use equal recoveries (71 seconds), short recoveries (30-60 seconds), or long recoveries (5-6 minutes)? Of course, the long recoveries are attractive because they would drive down fatigue and help keep Ben on course with his planned pace during the work intervals, thus bolstering his economy at goal velocity.

The best advice, though, is that Ben should start with roughly equal - not long - recoveries and then try to shorten them a bit. By doing so, he’ll produce considerably higher rates of oxygen use over the course of the workout than with the long recovery scenario, and blood-lactate profiles will also be better. Interestingly enough, he’ll also be in good shape from an economy standpoint, as long as his pace doesn’t drop off too much during those seventh, eighth, and ninth intervals. (We won’t worry about the tenth one, since it is always - miraculously - the fastest interval of the whole workout.) True, if Ben hits several intervals slower than 78 seconds-or-so during the second half of the workout, it’s time for him to either increase his motivation and mental focus or add a little bit of fat to his recoveries. As long as he can complete the intervals in close to the planned time, however, he should hang in there with equal recoveries - and then shorten them as fitness improves and the workout becomes more manageable.

It’s true that if you don’t care about vVO2max and lactate threshold and simply want to improve economy, you should go ahead and use 5:1 (which in Ben’s case would mean six-minute recoveries for each 71-second work interval). This would be great for the 400m runner, who has few concerns about aerobic capacity and lactate threshold. However, distance athletes do care about those key variables, and casting aside the training stimuli which help optimise them is not usually a sound practice.

Although I have focused so far on the impact of interval training on VO2max, lactate threshold and economy, it’s important to recognise that interval training can also have a strong influence on the development of strength and power. I have assumed so far that interval workouts consist only of running, cycling, rowing, swimming or skiing segments at various speeds, but of course they can also include strengthening exercises. The renowned running coach Percy Cerutty made great use of such muscle-bolstering activities, calling on runners like Herb Elliott and John Landy to carry out a variety of strengthening moves within the context of ‘circuit’ workouts, which also included hard-pressed runs up severe sand dunes. Elliott was never beaten in the mile or 1500m, ran a 3:59.9 mile at the age of 19 and a 3:54.5 mile just one year later, then in 1960 carried off four sub-four-minute miles in a three-week time span, just before winning the 1500m Olympic gold medal with a world-record time of 3:35.6!

Strength movements can boost race times

That’s anecdotal evidence, course, but Finnish researcher Laina Paavolainen recently provided strong evidence that workouts which combine high-speed running intervals with explosive strengthening movements (hops, jumps, bounds, presses etc) can significantly improve 5k race times (11). In this study, runners who increased mileage from 45 to 70 miles per week failed to improve 5k times, while runners who remained at 45 miles but added explosive running and strength drills to their training bettered their 5k performances by around 30 seconds. In effect, the explosive group replaced 32% of the training volume of the 70-mile group with the explosive drills - almost exactly the percentage of training time which Cerutty had suggested reserving for strengthening work. The explosively trained runners improved running economy and overall power on a high-speed treadmill test, while the 70-mile runners were unable to do so. Interestingly enough, Paavolainen’s group found that max running velocity was a good predictor of 5k time, as was footstrike time (the amount of time a runner spends in the ’stance phase’ of the gait cycle).

One special interval training technique involves carrying out intervals in two completely different aerobic activities within a single workout. For example, triathletes frequently perform both high-speed bike and running intervals within a single session, and even ‘almost-pure’ runners sometimes venture onto a bike during - or at least on the day of - a running interval workout. The idea, of course, is that this accumulation of high-intensity aerobic work will have a greater-than-usual impact on VO2max and perhaps lactate threshold. This seems fairly sensible: for example, a 5k runner who has completed six 800m running intervals within a workout would baulk at the very idea of another leg-muscle-tearing running interval or - worse still - two or three more running intervals; but that same runner could clamber onto a bike after the sixth interval and knock off several 5-6-minute cycling intervals, without impact damage to the leg muscles and without impairing recovery.

So far research doesn’t support the idea, though; in fact it suggests that such cross training is not a good way to try to boost VO2max (12). The research hasn’t been carried out in an optimal way, however since it has really examined the effects of replacing one discipline with another - running training with biking, for example. Of course, when that happens the poor runner will make fewer gains in running capacity (adaptations to training are sport-specific, after all); the idea is to add intervals in a ‘cross’ sport to what one is already doing. Such additions have not been closely investigated but are anecdotally appealing.

If increasing the length of work intervals and reducing those of recovery intervals is a good idea, what about actual work interval intensity? Is there a certain speed which optimises fitness improvement? Should one carry out work intervals at vVO2max? At lactate-threshold speed? Halfway between vVO2max and lactate threshold? At race pace?

Do some workouts at race speed

These questions have been hotly debated by athletes, coaches and exercise scientists, and it is clear that it makes sense to carry out some interval workouts at - or around - actual race velocities. For example, a runner completing 1600m work intervals at her current 5k race pace will no doubt improve efficiency (economy) at this speed, making it more likely that she will be able to move up to higher velocities in future races. In a similar vein, a runner performing work intervals at goal 5k pace (perhaps four seconds per 400m faster than current 5k pace), will find it easier to actually run at goal speed in a race because of the resulting gains in efficiency and confidence.

However, there are times when no racing is taking place, so there are no current race times available to govern training. In addition, many exercise scientists argue that it makes more sense to train at intensities which are judged optimal for producing selected physiological responses (for example, the improvement of lactate-threshold speed), since these physiological improvements will ultimately determine overall performance.

One such intensity, for example, would be vVO2max (an athlete’s rate of movement when VO2max is attained). vVO2max is an outstanding predictor of performance, and a moment of reflection reveals why this is so: an athlete might have an extremely impressive VO2max but still perform rather poorly if somewhat mediocre movement speeds caused him to utilise almost all of that considerable oxygen-processing capability. In other words, if the athlete were inefficient (ie using a lot of oxygen to sustain a mundane pace) the voluminous VO2max would be of little benefit.

Why high VO2max may be a false positive

By contrast, an athlete with a very high vVO2max can move very fast at her VO2max intensity and thus is obviously fairly efficient. In effect, the athlete enjoys the best of both worlds - a very high aerobic capacity and very great efficiency. vVO2max thus becomes a powerful predictor of performance, while VO2max and economy by themselves carry much less information and thus are less predictive. An athlete with great economy, for example, might have a poor VO2max and thus be unable to reach high speeds at VO2max; his terrific economy would thus give a ‘false positive’ test for good performance.
Since vVO2max is so tightly linked with success, it makes sense for endurance athletes to carry out interval workouts which have the greatest chance of optimising this variable. The noted French researcher Veronique Billat has been able to show that the best way to do this is by utilising vVO2max itself during training. Again, a moment’s thought reveals why this is the case: by working at vVO2max, you improve neuromuscular coordination and efficiency while moving very fast. Most importantly, you are certain of attaining VO2max intensity within the training session, providing the optimal stimulus for VO2max to expand further.

But how do you determine your vVO2max? As I have pointed out in these pages before, you can do this quite easily: on a day when you are feeling great, simply run, cycle, swim, race-walk, row or ski as far as you can in six minutes and then compute your distance. For example, if you’re a runner and you ran 2000m in six minutes, your vVO2max would be 2000/360 or 5.55m per second (72 seconds per 400m). If you ran 1600 meters in six minutes, your vVO2max would be 1600/360 = 4.44m per second (90 seconds per 400m).

In a recent study, Billat asked eight experienced runners to take part in four weeks of training which included one interval session per week at vVO2max. The athletes specialised in middle and long-distance running (1500m to half-marathon), their mean age was 24, and average VO2max was a respectable 71.2 ml/kg/min (13).

During the four-week period, the runners completed one vVO2max interval workout per week, consisting of five three-minute work intervals at vVO2max, with three-minute jog recoveries. The rest of the running during the week was easy, except for a ‘lactate-threshold-improving’ session, which consisted of two 20-minute work intervals at 85% of vVO2max, with a five-minute easy-jog recovery between the two intervals. Total distance covered by the runners per week was about 50 miles.
Billat’s vVO2max and lactate-threshold intervals were simple - and simply devastating. After four weeks, vVO2max rose by 3% - from 20.5k/hour to 21.1k/hour. In addition, running economy improved by an astounding 6%, while heart rate at 70% VO2max dropped by 4%. Although lactate threshold held steady at 84% of vVO2max, since vVO2max was higher after four weeks, velocity at lactate threshold also increased. Almost all of the key physiological variables associated with performance had improved!

Note in particular the dramatic improvement in economy (6%) achieved by Billat’s runners, an almost unheard-of increase in efficiency in well-trained competitors, especially within such a short time frame. The reason for this efficiency groundswell is that exercising at vVO2max increases leg-muscle strength and power, and enhanced strength tends to boost economy; since muscle cells are stronger, fewer need to be recruited to move at particular paces, and thus the overall ‘cost’ of movement is reduced. In addition, vVO2max exertion boosts neuromuscular responsiveness and coordination far more than does lethargic pacing; and increased coordination also reduces energy expenditure.

Billat’s 30-30 regime

Bear in mind that Billat’s interval training seems to ‘bring things together’ (ie boost economy, vVO2max and lactate-threshold speed simultaneously), so it’s not too much of a stretch to say that it would be ideal training for the last four weeks before a major competition. However, it is also important to do some vVO2max work at the beginning of the year, because it will kick-start fitness and improve the quality of the ensuing training. If things are proceeding correctly, of course, the speed of the vVO2max intervals will increase as time goes by. (You’ll want to perform the six-minute test every six to eight weeks to obtain a new vVO2max for yourself).

Very recently, Veronique has formulated a pair of vVO2max interval sessions which lead to impressive gains in fitness. In one of the new workouts, the idea is to warm up thoroughly and then alternate just 30 seconds of moving along at vVO2max (instead of the classic but agonising three minutes) with 30 seconds of ‘floating’ at 50% of vVO2max (14).

In her new research on this 30-30 pattern, Billat studied eight well-trained male endurance runners whose average age was 34. Prior to the study, these athletes were running about 35-40 miles per week. Their average VO2max was a pretty decent 60 ml/min.kg-1, mean vVO2max was 18.5k/hr (a pace of 5:13 per mile), and their lactate-threshold velocity was 82% of vVO2max, or 15.2 k/hr (6:21 per mile).

Build up to the classic interval

After these runners were evaluated for VO2max, vVO2max, and lactate-threshold running speed, they began to use the key workout: after warming up with 15 minutes of easy jogging, they alternated 30-second work intervals at 100% of vVO2max with 30-second recoveries at 50% of vVO2max, sustaining this pattern for as long as possible. For example, a runner who had a vVO2max of 20k/hr (5.55 meters per second) would run for 30 seconds at 5.55 m/second (166m) during the 30-second work intervals and about half that distance,thus achieving 50% of vVO2max, during the 30-second recoveries.

Incidentally, if you are wondering about the curious exactness of the recovery interval intensity, it is believed that hitting 50% of vVO2max ‘right on the head’ during recovery intervals is not that important, since the fitness gains associated with the workout come from the vVO2max work, not specifically from the recovery effort. It is important, however, for the recoveries to be run slowly and easily - at some speed reasonably close to 50% of vVO2max - so that 100% of vVO2max and not some lower intensity can be sustained during the work intervals.As it turned out, the somewhat unusual strategy of alternating 30 seconds at vVO2max with 30 seconds of floating produced an average of 19 intervals at vVO2max before exhaustion set in, 9mins 30secs of high-quality running, and a grand average of 7mins and 51secs at VO2max (83% of the total), which is considered to be excellent.

Interestingly enough, three individuals were able to complete 22-27 intervals during the 30-30 workout, with as many as 18.5 minutes completed at actual VO2max. If you are wondering how 27 30-second work intervals can lead to 18.5 minutes at VO2max (instead of 13.5 minutes or less), bear in mind that the runners often sustained VO2max during the 30-second recovery intervals, too, even though they were running at only half of vVO2max! Obviously, there was a ‘physiological lag’ occurring, with the runners’ bodies taking longer than 30 seconds to downshift oxygen usage as running pace slowed.
The 30-30 workout is a powerhouse; and even though heart rate soars to near maximal near the end of the session, it is tolerated well even by rather inexperienced runners who tend to really struggle with the more-challenging ‘classic’ (5 x 3 minutes @ vVO2max). Indeed, Veronique has carried out new experimental work with modestly fit physical education students (VO2max = 54 ml/min.kg-1) showing that a twice-weekly regimen of 30-30 workouts can boost VO2max by a whopping 10% in just 8-10 weeks!

Veronique recommends using the 30-30 session early in the season to kick-start improvements in VO2max, vVO2max, lactate threshold, and running economy. Anecdotally, 30-30, even when it is carried out to the point of exhaustion (ie the point at which vVO2max can no longer be sustained for a 30-second work interval), appears to be a little easier on runners’ muscles and tendons than the crueller ‘3-3′ session (5 x 3 minutes at vVO2max, with 3-minute recoveries).

After a month or so, you can progress from 30-30 to another Billat workout, the ‘60-60′ (60 seconds at vVO2max alternating with 60 seconds of floats, again until exhaustion). Once you have become a master of 60-60, you can then begin the classic (and much tougher) three-minute interval at vVO2max workout to further improve vVO2max, VO2max, lactate threshold, and economy - and also enhance another variable known as tlimvVO2max - the amount of time you can run continuously at vVO2max before fatigue stops you. tlimvVO2max also happens to be an excellent predictor of endurance performance in its own right.
That covers vVO2max, but which interval workouts are best for lactate-threshold improvement? Which ones are best for economy? How about pure strength?

Boosting lactate threshold

For boosting lactate threshold, you would go for interval sessions which allow you to reach VO2max for a considerable portion of the workout and which feature high rates of lactate production and appearance in the blood. Attainment of VO2max makes the heart - in the long run - a better pump and also forces muscle cells to make more energy-producing mitoc-hondria and synthesise new aerobic enzymes. When there is a lot of lactate around, the muscles get better at clearing lactate from the blood. Combine these responses and you can achieve a dramatic lift-off in lactate-threshold speed. Interval workouts which fit the bill include Veronique’s vVO2max session and another exertion in which two-minute, close-to-max bursts are alternated with about four minutes of ‘coasting’ at moderate intensity - recovery intervals which can be reduced in time.

For improving economy it is very hard to beat Veronique’s vVO2max effort; other very good sessions would involve working at your current or goal race speeds for 2-6 minutes at a time, with initially equal recovery periods. Circuit workouts are terrific for building general and sport-specific strength, but the ‘exercise intervals’ within the circuits should progress over time, becoming more and more like the actual movements used in your particular sport. Sessions which combine running and strengthening intervals can be used to promote power, too; the idea is to work not just on force production but on the rate of force production. The chosen exercises will have to be carried out at high speeds, and the running intervals will be very intense.

Owen Anderson

Veronique Billat is at it again. The French scientist who brought that proud old physiological variable VO2max to its knees, replacing it with the much more valuable and predictive vVO2max, and who was the first scientist to show endurance athletes exactly how to optimize vVO2max, has now developed two new vVO2max-expanding workouts which can produce huge improvements in performance.

The concept of vVO2max can be simply defined as the velocity which produces the highest-possible rate of oxygen consumption. The classic Billat strategem for hoisting vVO2max, as well as lactate threshold and efficiency of movement (economy), was a workout consisting of five three-minute intervals at vVO2max, with three-minute ‘float’ recoveries after the intervals. The diminutive genius from the University of Lille was able to show experimentally that this simple workout, carried out on a weekly basis, could upgrade vVO2max and lactate threshold by 3% and economy by 6% in as short a time as nine weeks (1).

Never one to rest on her laurels, Billat has now developed a pair of vVO2max sessions which can lead to impressive gains in fitness. In one of the new workouts, the idea is to warm up thoroughly and then alternate just 30 seconds of moving along at vVO2max (instead of the classic but agonising three minutes) with 30 seconds of ‘floating’ at 50% of vVO2max (2). In her new research, Billat studied eight well-trained male endurance runners, with an average age of 34, who were running about 35-40 miles per week. Their average VO2max was a pretty decent 60 ml/min.kg-1, their mean vVO2max was 18.5 km/hr (a pace of 5:13 per mile) and their lactate-threshold velocity was 82% of vVO2max, or 15.2 km/hr (6:21 per mile).

After these runners were evaluated for VO2max, vVO2max, and lactate-threshold running speed, they carried out two different workouts, as follows:

1. After warming up with 15 minutes of easy jogging, they alternated 30-second work intervals at 100% of vVO2max with 30-second recoveries at 50% of vVO2max, sustaining this pattern for as long as possible. For example, a runner who had a vVO2max of 20 km/hr (5.55m per second) would run 166 metres during the 30-second work intervals and about half that distance (83m) during the 30-second recoveries, thus achieving 50% of vVO2max. If you are worrying about the exactness of the recovery interval, let me reassure you that hitting 50% of vVO2max ‘right on the head’ during recovery intervals is not that important; the gains in fitness associated with the workout come from the vVO2max work, not specifically from the recovery effort. It is important, however, for the recoveries to be run slowly - at some speed reasonably close to 50% vVO2max - so that you can sustain 100% of vVO2max, and not some lower percentage, during the work intervals.

2. The second workout was a continuous run (no work intervals, no rest intervals - just hard, sustained running) in which the athletes warmed up and then ran for as long as possible at a speed exactly halfway between their lactate-threshold velocity and vVO2max. In practice, this turned out to be an average of about 91% of vVO2max, or approximately 16.9 km/hr (5:43 per mile).

Thus, during the at-vVO2max interval workout, the athletes were running at an average tempo of 78 seconds per 400m, but in 30-second ‘chunks’, while in the continuous session the runners scampered along at 85 seconds per 400m without stopping. In both cases, Billat’s athletes kept working as long as they possibly could. The athletes conducted both sessions on a synthetic track while breathing through a portable telemetric metabolic analyser, which allowed Billat to determine their actual rates of oxygen consumption.

Is this strange, or what?

Strangely enough, when the athletes carried out the continuous workout at a speed halfway between lactate threshold and vVO2max (ie at a velocity lower than vVO2max), more than half of the runners (five out of eight) actually reached their maximum rate of oxygen consumption!

Hold on, you must be saying! Isn’t vVO2max the running speed which elicits VO2max? How could five of the runners move along at an intensity halfway between lactate threshold and vVO2max - ie 9-% slower than vVO2max - and still pull good-old VO2max out of the hat?

If that question troubles you, bear in mind that ‘Veronique’s vVO2max’ is reached in the laboratory during a treadmill test in which running speed is steadily and progressively increased in an effort to make the rate of oxygen consumption rise as high as possible. Each specific velocity utilised in this test is sustained for a relatively short period of time, and the first velocity which corresponds with VO2max is chosen as vVO2max.

Now you see it! Since each velocity in Veronique’s test is ‘touched on’ for a relatively brief period, it is quite possible that a speed slower than Veronique’s vVO2max could actually elicit VO2max - if it were given enough time to do so! Veronique’s test, however, does not permit dawdling at various speeds, so vVO2max is reached at a rather high speed (that is to say, a higher speed than the minimal velocity which would provoke VO2max).

Although that makes the ‘halfway-between lactate threshold and vVO2max’ workout seem pretty good (since it could call up VO2max in more than 50% of the runners), the trouble with the halfway workout was that it actually produced VO2max for a very short duration of time within the workout. In fact, VO2max was sustained for an average of only two minutes and 42 seconds during the halfway session, even though runners were able to keep going at the halfway pace for an average of eight minutes and 20 seconds (the rest of the time, of course, being spent below VO2max). Thus, just 32% of total running time was performed at VO2max.

Now is not the time to think: ‘So what?’ Remember that time spent at VO2max is a critically important variable during training. Many experts believe (with backing from research) that time passed at VO2max during training is a much more potent fitness expander for endurance athletes than time spent at 80, 90 or even 95% VO2max. The reason for this is clear: if you are forcing your heart to send as much oxygen as possible to your muscles and also forcing your muscles to use the incoming oxygen at the highest-possible rate, that creates a maximal stimulus for the heart and muscles to adapt by enhancing the body’s capacity to process oxygen. If you use a less intense stimulus, the muscles and heart will ‘believe’ they are meeting the demands of training quite well (since you haven’t tried to push through the upper limit of O2 utilisation) and you will thus generate a smaller adaptive response to the training.

Much better results for 30-30

While the continuous running at a pace halfway between lactate-threshold speed and vVO2max led to a paltry total of less than three minutes at VO2max and 8:20 of overall running, the somewhat unusual strategy of alternating 30 seconds at vVO2max with 30 seconds of floating produced an average of 19 intervals at vVO2max before exhaustion set in, 9:30 of high-quality running, and a grand average of seven minutes and 51 seconds at VO2max (83% of the total). In other words it produced 19% more VO2max running than the continuous run! An additional 309 seconds were spent at VO2max during the 30-30 workout compared with the continuous run, yet blood-lactate levels were similar in the two efforts!

Interestingly, three individuals were able to complete between 22 and 27 intervals during the 30-30 workout, with as many as 18.5 minutes completed at actual VO2max. By contrast, the most expansive time spent at VO2max during the continuous run was seven minutes. If you are wondering how 27 30-second work intervals can lead to 18.5 minutes at VO2max (instead of, say, 13.5 minutes or less), bear in mind that runners often sustained VO2max during the 30-second recovery intervals too, even though they were running at only half of vVO2max! Obviously, there was a ‘physiological lag’ occurring, with the runners’ bodies taking longer than 30 seconds to downshift oxygen usage as running pace slowed.

When the three subjects who hit 22-27 intervals during the 30-30 run tried the continuous exertion, one runner did not even reach VO2max, despite lasting seven minutes at the continuous pace! Another runner ran at VO2max for just 5:45, and the athlete who crested at VO2max for 18:30 during the 30-30 workout logged his max oxygen-burning rate for only 4:30 during the continuous run. These are huge differences!

The 30-30 workout is a powerhouse and, even though heart rate soars to near maximal near the end of the session, it is tolerated well, even by rather inexperienced runners, who tend to struggle with the more-challenging (5 x 3 minutes @ vVO2max) ‘classic.’ Indeed, Veronique has carried out new experimental work with modestly fit physical education students (VO2max = 54 ml/ min.kg-1) showing that a twice-weekly regimen of 30-30 workouts can boost VO2max by a whopping 10% in just 8-10 weeks!

Veronique recommends using the 30-30 session early in the season as an excellent, easily-tolerated way to kick-start improvements in VO2max, vVO2max, lactate threshold, and running economy. Anecdotally, 30-30, even when carried out to the point of exhaustion (ie the point at which vVO2max can no longer be sustained for a 30-second work interval) appears to be a little easier on runners’ muscles and tendons than the crueller ‘3-3′ session (5 x 3 minutes at vVO2max, with 3-minute recoveries).

After a month or so, you can progress from 30-30 to another Billat workout, the ‘60-60′ (60 seconds at vVO2max alternating with 60 seconds of floats, again until exhaustion calls your name). Once you have become a master of 60-60, you can begin the classic (and much tougher) three-minute-interval-at-vVO2max workout to further improve vVO2max, VO2max, lactate threshold, and economy - and also broaden something called tlimvVO2max (the amount of time you can run continuously at vVO2max before stopping from fatigue). It so happens that tlimvVO2max is an excellent predictor of endurance performance in its own right.

Rating the workouts

Will 5 x 3 minutes improve VO2max, vVO2max, lactate threshold, and running economy more effectively than 30-30 and 60-60? In many cases, the answer is yes: the average time at VO2max during the 5 x 3 is around 10 minutes, about 25% more high-octane time than during the 30-30. Thus, moving from 30-30 to 5 x 3 is a beautiful progression, both in terms of the ease with which the workout can be accomplished and also the magnitude of the stimulus for physiological improvement.

Note, though, that individual variations might make the 30-30 better than 5 x 3 for some athletes. This is probably true of the athlete mentioned above, who lasted for 27 intervals during 30-30, totalling up 18:30 at VO2max; even if this runner spent all of 5 x 3 at VO2max, which is most unlikely, he would not be able to amass as much time at VO2max as he had done with the 30-30 effort. If you are the kind of runner who can handle more than 20 work intervals with the 30-30 session, you may want to think about alternating 30-30 with 5 x 3, even during the later stages of your overall training progression. Taking another course - shifting to 6 x 3 or even 7 x 3 - is not recommended, as the basic 5 x 3 appears to be quite challenging to the musculoskeletal system, even for experienced runners.

If you are new to PP and are not sure how to calculate your vVO2max, simply go to the track on a day when you are feeling great, the wind is a non-factor, the temperature and humidity are salubrious and your mental stress levels are low. After a great warm-up, set sail on the track at the fastest speed you can sustain for six minutes. After six minutes, mark where you are on the track and compute your vVO2max. For example, if you have travelled 1800 metres, your vVO2max would be 1800/6 = 300m/minute, or 5m per second. This, of course, would be a tempo of 80 seconds per 400m.

Your classic workout would then be 5 x 900m in three minutes each, with three-minute jog recoveries. The new 30-30 workout would be alternations of 30 seconds at 5m per second pace with 30 seconds of float - until you could go no more. That, of course, means that you would cover 150m in 30 seconds, about 75m in the next 30 seconds, 150m in the next half-minute, and so on - until your legs feel like stones. The 60-60 would entail 300m in one minute, 150m in the next minute, 300m in the following minute, etc.

It may be a good idea to get hold of a set of orange, plastic cones, which can be placed around the track at strategic locations, corresponding to the distances you need to run for your 30-, 60-, or even 180-second intervals. Since your actual pace during the recovery intervals is not critically important (as long as the pace is easy), your best bet will be to mark off your work-interval distance with great accuracy. You can then simply jog easily during your recovery interval, making sure that you are at one end of your work-interval arc when the next work interval begins.

Incidentally, if you are a cyclist (or triathlete) and want to know your vVO2max on the bike, you can perform exactly the same test as I have described for runners: on a day when you are feeling terrific, warm up and then ride as far as possible in six minutes. Figure out your distance covered and thus your vVO2max. You are then ready for some great vVO2max-enhancing workouts, namely:

1. Cycle 1/12 of your vVO2max test distance in 30 seconds, easy pedal for 30 seconds, 1/12 of the distance in 30 seconds etc until exhaustion;

2. Cover 1/6 of your vVO2max test distance in 60 seconds, easy pedal for 60 seconds, and so on;

3. Cycle 5 x 3 minutes at vVO2max, with 3-minute recoveries. Experienced bikers can complete more than five three-minute intervals if they wish, since the impact forces associated with biking are much lower than for running.

Swimmers and rowers can, of course, follow exactly the same protocol for vVO2max testing and training. Naturally, runners, cyclists, swimmers, and rowers will want to re-check their vVO2max, using the six-minute test, every 4-6 weeks or so, then use the new vVO2max as the appropriate training speed.

Background and summary information

1. In a paper published in 1984, which still makes good reading, the famed coach Jack Daniels was the first scientist to describe the importance of a runner’s actual running speed at VO2max (maximal aerobic capacity), which he termed vVO2max (3).

2. vVO2max is generally defined as the minimal velocity which elicits VO2max in an incremental exercise protocol (ie a test in which a runner’s rate of oxygen consumption is assessed while running speed is increased in specific increments - often 1 km/hr - with each speed sustained for a relatively short period of time - usually two minutes).

3. Although runners and exercise physiologists refer to vVO2max as though it were a single entity, there are actually many vVO2maxs, ie many speeds which would cause a runner to ‘hit’ VO2max before reaching exhaustion. If this seems incredibly confusing, remember that the incremental exercise test used to determine vVO2max allows runners to remain at each speed for only a short period of time (often two minutes). As a result, a runner might be very close to VO2max but not actually reach it while running at 17 km/hr, for example, but then ’strike VO2max gold’ while sizzling along at the next test speed of 18 km/hr. According to the test, the runner’s vVO2max would thus be 18 km/hr, but in truth if the runner had been allowed to keep running for longer at 17 km/hr, he might well have been able to ‘hit’ VO2max at the slower speed; at high-quality running speeds, oxygen-consumption rate tends to climb even when speed is absolutely constant, an effect which is often called the ’slow component of oxygen uptake’. To make matters even more interesting, many runners can run about 40% faster than vVO2max and still stir up VO2max for a brief period before falling prostrate on the track. While this ‘140% of vVO2max’ might be sustained for only 70 seconds or so and VO2max itself might be reached for only the last 15-18 seconds of the brief effort, nonetheless VO2max is attained and 140% of vVO2max would also qualify as a ‘vVO2max’.

4. With so many vVO2maxs to choose from, Veronique Billat has made a serious and elegant effort to find the vVO2max which, when used in training, would produce the greatest gain in performance. Ingeniously, Billat has developed her six-minute test (an all-out effort lasting six minutes, with vVO2max calculated as average velocity) and has also shown that a workout consisting of 5 x 3 minutes at vVO2max, with three-minute recoveries, is an incredible booster of vVO2max, lactate threshold, running economy, and performance.

Owen Anderson

1. Rufor Says:
   March 1st, 2009 at 10:34 pm

   Hi there,
   Thank you! I would now go on this blog every day!

   Have a nice day
   Rufor

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