Effects of moderate-intensity endurance and high-intensity

intermittent training on anaerobic capacity and ·VO2max

[Applied Sciences: Physical Fitness and Performance]

TABATA, IZUMI; NISHIMURA, KOUJI; KOUZAKI, MOTOKI; HIRAI, YUUSUKE;

OGITA, FUTOSHI; MIYACHI, MOTOHIKO; YAMAMOTO, KAORU
Department of Physiology and Biomechanics, National Institute of Fitness and Sports, Shiromizu-cho 1, Kanoya City, Kagoshima
Prefecture, 891-23 JAPAN
Submitted for publication November 1994.
Accepted for publication December 1995.
The training protocol used in experiment 2 was first introduced by Kouichi Irisawa, who was a head coach of the Japanese National Speed
Skating Team. The training has been used by the major members of the Japanese Speed Skating Team for several years.
Present addresses: I. Tabata, Laboratory of Exercise Physiology, Division of Health Promotion, National Institute of Health and Nutrition,
1-23-1 Toyama, Shinjuku City, Tokyo 162 Japan; Y. Hirai, Number 1 Fitness Club, 5-14-6 Shimo-Takaido, Suginami City, Tokyo 168
Japan; K. Nishimura, General Research and Development Section, Product Development Department, Moon-Star Chemical Corporation,
Kurume City, Fukuoka Prefecture, 830-91 Japan; F. Ogita, Swimming Performance Laboratory, National Institute of Fitness and Sport,
Shiromizu-cho 1, Kanoya City, Kagoshima Prefecture, 891-23 Japan; M. Miyachi, Department of Health and Sports Sciences, Kawasaki
University of Medical Welfare, 288 Matsushima, Kurashiki City, Okayama Prefecture, 701-01 Japan; and K. Yamamoto, Nagoya YMCA, 2-
5-29 Kamimaezu, Naka-ku, Nagoya City, Aichi Prefecture, 460 Japan.
Address for correspondence: I. Tabata, Ph.D., Laboratory of Exercise Physiology, Division of Health Promotion, National Institute of
Health and Nutrition, 1-23-1 Toyama, Shijuku City, Tokyo 162, Japan.

ABSTRACT

This study consists of two training experiments using a mechanically braked cycle ergometer. First, the effect of
6 wk of moderate-intensity endurance training (intensity: 70% of maximal oxygen uptake (·VO 2max), 60 min·d-1,
5 d·wk-1) on the anaerobic capacity (the maximal accumulated oxygen deficit) and ·VO2max was evaluated. After
the training, the anaerobic capacity did not increase significantly(P > 0.10), while ·VO2max increased from 53 ± 5
ml·kg-1·min-1 to 58 ± 3 ml·kg-1·min-1 (P < 0.01) (mean± SD). Second, to quantify the effect of high-intensity
intermittent training on energy release, seven subjects performed an intermittent training exercise 5 d·wk-1 for 6
wk. The exhaustive intermittent training consisted of seven to eight sets of 20-s exercise at an intensity of about
170% of ·VO2max with a 10-s rest between each bout. After the training period, ·VO2max increased by 7 ml·kg-
1
·min-1, while the anaerobic capacity increased by 28%. In conclusion, this study showed that moderate-intensity
aerobic training that improves the maximal aerobic power does not change anaerobic capacity and that adequate
high-intensity intermittent training may improve both anaerobic and aerobic energy supplying systems
significantly, probably through imposing intensive stimuli on both systems.

During high-intensity exercise lasting more than a few seconds, adenosine triphosphate (ATP) is resynthesized
by both aerobic and anaerobic processes (7). The ability to resynthesize ATP may limit performance in many
sports. Thus, if possible, the training of athletes for sports involving high-intensity exercise should improve the
athletes' ability to release energy both aerobically and anaerobically. The success of different training regimens
can and should be evaluated by the athletes' performance. However, performance is influenced by other factors
such as psychology. In addition, an adequate training regimen may have several different components, all of
which may not improve the athletes' ability to resynthesize ATP. Training programs should therefore be
evaluated by other means, e.g., by laboratory experiments.

The aerobic energy releasing system is conventionally evaluated by maximal oxygen uptake (·VO 2max) (10), and
there are many studies on the effect of training on ·VO 2max(9). However, until recently methods for quantifying
anaerobic energy release have been inadequate and thus information on the effect of training on anaerobic
capacity, i.e., the maximum amount of energy available from anaerobic sources, is incomplete. We have
proposed that the accumulated oxygen deficit, first introduced by Krogh and Lindhard in 1920 (4), is an
accurate measure of the anaerobic energy release during treadmill running (6) and bicycling (7). This principle
may allow examination of the anaerobic capacity (3), taken as the maximal accumulated oxygen deficit during
2-3 min of exhaustive exercise (6,7). Therefore, the effect of specific training on the anaerobic capacity may be
evaluated by measuring the maximal accumulated oxygen deficit before and after training. Generally, the more
demanding the training, the greater the fitness benefits. Therefore, we were interested in learning whether the
effects of training on anaerobic capacity are dependent on the magnitude of anaerobic energy release developed
by the specific training. To study this issue, we compared two different training protocols: a moderate-intensity
endurance training that is not supposed to depend on anaerobic metabolism and a high-intensity intermittent
training that is supposed to recruit the anaerobic energy releasing system almost maximally.

MATERIALS AND METHODS

Subjects. Young male students majoring in physical education volunteered for the study (Table 1). Most were
physically active and were members of varsity table tennis, baseball, basketball, football (soccer), and
swimming teams. After receiving a detailed explanation of the purposes, potential benefits, and risks associated
with participating in the study, each student gave his written consent.

TABLE 1. Characteristics of the subjects.

From: TABATA: Med Sci Sports Exerc, Volume 28(10).October 1996.1327-1330

Protocol. All experiments, as well as pretests, were done on a mechanically braked cycle ergometer (Monark,
Stockholm, Sweden) at 90 rpm. Each test or high-intensity intermittent training session was introduced by a 10-
min warm-up at about 50% of ·VO2max.

Experiment 1. The subjects started training after their·VO2max and maximal accumulated oxygen deficit were
measured. They exercised 5 d·wk-1 for 6 wk at an intensity that elicited 70% of each subject's ·VO2max. The
pedaling rate was 70 rpm, and the duration of the training was 60 min. As each subject's ·VO 2max increased
during the training period, exercise intensity was increased from week to week as required to elicit 70% of the
actual ·VO2max. During the training, the maximal accumulated oxygen deficit was measured before, at 4 wk, and
after the training. ·VO2max was determined before and after the training and every week during the training
period.

Experiment 2. Subjects exercised for 5 d·wk-1 for 6 wk. For 4 d·wk-1, they exercised using exhaustive
intermittent training. They were encouraged by the supervisor to complete seven to eight sets of the exercise.
Exercise was terminated when the pedaling frequency dropped below 85 rpm. When they could complete more
than nine sets of the exercise, exercise intensity was increased by 11 W. One day per week the subjects
exercised for 30 min at an intensity of 70% ·VO 2max before carrying out four sets of the intermittent exercise at
170%·VO2max. This latter session was not exhaustive. The anaerobic capacity was determined before, at 2 wk,
and 4 wk into the training, and after the training. ·VO2max was determined before, at 3 wk, 5 wk, and after the
training.

METHODS

Pretest. Each subject's oxygen uptake was measured during the last 2 min of six to nine different 10-min
exercise sets at constant power. The power used during each set ranged between 39% and 87% of the·VO 2max. In
addition, the power that would exhaust each subject in 2-3 min was established. These pretests were carried out
on 3-5 separate days.
·VO2max. After a linear relationship between exercise intensity and the steady-state oxygen uptake had been
determined in the pretests, the oxygen uptake was measured for the last two or three 30-s intervals during
several bouts of supramaximal intensity exercise that lasted 2-4 min. The highest ·VO 2 was determined to be the
subject's·VO2max (7,10).

Anaerobic capacity. Anaerobic capacity, the maximal accumulated oxygen deficit during a 2-3-min exhaustive
bicycle exercise, was determined according to the method of Medbø et al.(6,7). The exercise intensity used to
cause exhaustion within the desired duration (2-3 min) was established on pretests. On the day that anaerobic
capacity was measured, the subjects exercised at the preset power to exhaustin (defined as when they were
unable to keep the pedaling rate above 85 rpm).

Methods of analysis. Fractions of oxygen and carbon dioxide in the expired air were measured by a mass
spectrometer (MGA-1100, Perkin-Elmer Cetus, Norwalk CT). The gas volume was measured by a gasometer
(Shinagawa Seisakusho, Tokyo, Japan). Values are shown as means ± SD. The data were compared using a
paired t-test. The significance level for all comparisons was set at P < 0.05.

Calculations. For each subject linear relationships between the oxygen demand and power (experiment 1: r =
0.997 ± 0.001, experiment 2: r = 0.998 ± 0.001) were established from the measured steady state oxygen uptake
at different power during the pretests. The regression parameters are shown in Table 2. The regression
parameters did not change during training periods in either experiment 1 or 2.

TABLE 2. Regression characteristics of the subjects.

From: TABATA: Med Sci Sports Exerc, Volume 28(10).October 1996.1327-1330

The oxygen demands of the 2-3 min of exhausting exercise were estimated by extrapolating these relationships
to the power used during the experiment. The accumulated oxygen demand was taken as the product of the
estimated oxygen demand and the duration of the exercise, while the accumulated oxygen uptake was taken as
the measured oxygen uptake integrated over the exercise duration. The accumulated oxygen deficit was taken as
the difference between these two entities.

RESULTS

Experiment 1. After the 6 wk of training, the anaerobic capacity did not change (Fig. 1) (P > 0.10).
The·VO2max increased significantly during the training (Fig. 2) (P < 0.01).
Figure 1-Effect of the endurance training (ET, experiment 1) and the intermittent training (IT,
experiment 2) on the anaerobic capacity. Significant increase from the pretraining value at*P < 0.05 and
**P< 0.01; significant increase from the 2-wk value at#P < 0.05.
From: TABATA: Med Sci Sports Exerc, Volume 28(10).October 1996.1327-1330

Figure 2-Effect of the endurance training (ET, experiment 1) and the intermittent training (IT,
experiment 2) on the maximal oxygen uptake; significant increase from the pretraining value at*P < 0.05
and **P< 0.01, respectively.
From: TABATA: Med Sci Sports Exerc, Volume 28(10).October 1996.1327-1330

Experiment 2. The anaerobic capacity increased by 23% after 4 wk of training (P < 0.01, Fig. 1). It increased
further toward the end of the training period. After the training period, the anaerobic capacity reached 77 ± 9
ml·kg-1, 28% higher than the pretraining capacity.
After 3 wk of training, the ·VO2max had increased significantly by 5 ± 3 ml·kg -1·min-1 (P < 0.01, Fig. 2). It tended
to increase in the last part of the training period, but no significant changes were observed. The final·VO 2max
after 6 wk of training was 55 ± 6 ml·kg-1·min-1, a value of 7 ± 1 ml·kg-1·min-1 above the pretraining value.

DISCUSSION

The main finding of this study was that 6 wk of aerobic training at 70%·VO 2max improved the ·VO2max by 5
ml·kg-1·min-1 in moderately trained young men but that the anaerobic capacity, as judged by the maximal
accumulated oxygen deficit, did not change. The second finding is that 6 wk of training using high-intensity
intermittent exhaustive exercise improved ·VO2max by 7 ml·kg-1·min-1 and the anaerobic capacity by 28%.

The observation in experiment 1 that anaerobic capacity did not change after 6 weeks of moderate-intensity
endurance training but that·VO2max did increase has several implications. First, it shows the specificity of
training; aerobic training does not change anaerobic capacity. Since lactate production accounts for about 75%
of maximal anaerobic energy release (11), significant improvements in anaerobic capacity will probably require
that the subjects can produce more lactate after training. Consequently, lactate production should be stressed to
increase the anaerobic capacity during “anaerobic” training. However, since the blood lactate concentration
during the exercise was low (about 2 mmol·l-1), the major part of anaerobic energy released during the exercise
probably comes from the breakdown of phosphocreatine (PCr). Therefore, the training sessions in experiment 1
probably did not tax the lactate producing system much and therefore did not tax the whole anaerobic energy
releasing system to any significant extent. Actually, the accumulated oxygen deficit during the first minutes of
the exercise at 70%·VO2max was only 37 ± 6% (N = 7) of the maximal accumulated oxygen deficit (data not
shown).

Second, the results of experiment 1 support the idea that the accumulated oxygen deficit is a specific measure of
the maximal anaerobic energy release. Due to the increased ·VO2max after the training period, the subjects could
exercise for more than 6 min at the power used for the pretraining 2- to 3-min anaerobic capacity test.
Therefore, the exercise power for the posttraining anaerobic capacity test was increased by 6 ± 3% to exhaust
each subject in 2-3 min. However, the accumulated oxygen deficit appeared unaffected by the higher power
used at the posttraining test, suggesting that this entity is able to distinguish between aerobic and anaerobic
energy release at different powers. The alternative interpretation, that there was a change in the anaerobic
capacity but that this change was obscured by a bias in the accumulated oxygen deficit, cannot be ruled out, but
the findings here suggest that the latter interpretation is less likely.

The high-intensity intermittent training in experiment 2 improved anaerobic capacity by 28%. Medbø and
Burgers (5) reported that 6 wk of the intermittent training (their group B) increased the anaerobic capacity of
untrained men by 16%. Since there are no clear differences in exercise intensity, exercise duration, and number
of exercise bouts between the two studies, this quantitative difference in improving anaerobic capacity is
probably explained by the difference between the two studies in magnitude of the anaerobic energy release
during each training session. The peak blood lactate concentration after each training session in the previous
study (5) was 69% of the peak blood lactate concentration after the 2-min exhaustive running. Therefore,
anaerobic metabolism, and especially the lactate producing system, was probably not taxed maximally. In
contrast, the peak blood lactate concentration after the intermittent training in this investigation was not
significantly different from the value observed after the anaerobic capacity test that recruited anaerobic energy
releasing systems maximally. In addition, our subjects exercised to exhaustion, but in the previous study, the
subjects' rating of perceived exertion (1) was only 15 (“hard”). This difference may also reflect the recruited
level of anaerobic energy release. Therefore, these results support our hypothesis that the higher the anaerobic
energy release during each training session the higher the increase in anaerobic capacity after a training period.

In addition to anaerobic capacity, the intermittent training increased·VO2max significantly in experiment 2. This
is to our knowledge the first study to demonstrate an increase in both anaerobic capacity and maximal aerobic
power. It should be emphasized that during the last part of each training session the oxygen uptake almost
equaled each subject's maximal oxygen uptake (data not shown). High-intensity intermittent training is a very
potent means of increasing maximal oxygen uptake (2). It is interesting to note that the increase in the maximal
oxygen uptake that we found is almost identical to that expected for intermittent training by Fox (2).
Consequently, the protocol used in training in experiment 2 may be optimal with respect to improving both the
aerobic and the anaerobic energy releasing systems.

The intensive bicycle training may have affected the efficiency of cycling, meaning that the relationship
between power and ·VO2 may have changed. This change may affect the measurement of anaerobic capacity
because the accumulated oxygen deficit is a calculated entity assuming a constant mechanical efficiency.
However, our subjects were sufficiently familiar with bicycle exercise through repeated testing and experiments
so that the relationship between the steady state oxygen uptake and power did not change during the training
periods. Therefore, the pre- and posttraining data of the accumulated oxygen deficit should be comparable.

In summary, this investigation demonstrated that 6 wk of moderate-intensity endurance training did not affect
anaerobic capacity but that 6 wk of high-intensity intermittent training (20 s exercise, 10 s rest; intensity
170%·VO2max) may improve both anaerobic capacity and ·VO2max simultaneously.

REFERENCES

1. Borg, G. Perceived exertion as an indicator of somatic stress. Scand. J. Rehabil. Med. 2-3:92-98, 1970.
[Context Link]

2. Fox, E. Sport Physiology. Philadelphia: W.B. Saunders, 1979, pp. 226. [Context Link]

3. Hermansen, L., J. I. Medbo, A.-C. Mohn, I. Tabata, and R. Bahr. Oxygen deficit during maximal exercise of
short duration. (Abstract).Acta Physiol. Scand. 121:39A, 1984. [Context Link]

4. Krogh, A. and J. Lindhard. The changes in respiration at the transition from work to rest. J. Physiol. 53:431-
437, 1920. ExternalResolverBasic Bibliographic Links [Context Link]

5. Medbø, J. I. and S. Burgers. Effect of training on the anaerobic capacity. Med. Sci. Sports Exerc. 22:501-507,
1990. Ovid Full Text ExternalResolverBasic Bibliographic Links [Context Link]

6. Medbø, J. I., A.-C. Mohn, I. Tabata, R. Bahr, O. Vaage, and O. M. Sejersted. Anaerobic capacity determined
by maximal accumulated O2 deficit. J. Appl. Physiol. 64:50-60, 1988. [Context Link]

7. Medbø, J. I. and I. Tabata. Relative importance of aerobic and anaerobic energy release during short-lasting
exhaustive bicycle exercise. J. Appl. Physiol. 67:1881-1886, 1989. [Context Link]

8. Medbø, J. I. and I. Tabata. Anaerobic energy release in working muscle during 30 s to 3 min of exhausting
bicycling.J. Appl. Physiol. 75:1654-1660, 1993.

9. Saltin, B., G. Blomqvist, J. H. Mitchell, R. L. Johnson, Jr., and C. B. Chapman. Responses to exercise after
bed rest and after training. A longituinal study of adaptive changes in oxygen transport and body composition.
Circulation 38 (Suppl. 7):1-78, 1968. [Context Link]

10. Taylor, H. L., E. Buskirk, and A. Henshel. Maximal oxygen intake as an objective measure of
cardiorespiratory performance.J. Appl. Physiol. 8:73-80, 1955. [Context Link]

ANAEROBIC TRAINING; AEROBIC TRAINING