DUPONT, G., W. MOALLA, C. GUINHOUYA, S. AHMAIDI, and S. BERTHOIN. Passive versus Active Recovery during High-Intensity Intermittent Exercises. Med. Sci. Sports Exerc., Vol. 36, No. 2, pp. 302–308, 2004.
Purpose: To compare the effects of passive versus active recovery on muscle oxygenation and on the time to exhaustion for high-intensity intermittent exercises.
Methods: Twelve male subjects performed a graded test and two intermittent exercises to exhaustion. The intermittent exercises (15 s) were alternated with recovery periods (15 s), which were either passive or active recovery at 40% of V̇O2max. Oxyhemoglobin was evaluated by near-infrared spectroscopy during the two intermittent exercises.
Results: Time to exhaustion for intermittent exercise alternated with passive recovery (962 ± 314 s) was significantly longer (P < 0.001) than with active recovery (427 ± 118 s). The mean metabolic power during intermittent exercise alternated with passive recovery (48.9 ± 4.9 mL·kg−1·min−1) was significantly lower (P < 0.001) than during intermittent exercise alternated with active recovery (52.6 ± 4.6 mL·kg−1·min−1). The mean rate of decrease in oxyhemoglobin during intermittent exercises alternated with passive recovery (2.9 ± 2.4%·s−1) was significantly slower (P < 0.001) than during intermittent exercises alternated with active recovery (7.8 ± 3.4%·s−1), and both were negatively correlated with the times to exhaustion (r = 0.67, P < 0.05 and r = 0.81, P < 0.05, respectively).
Conclusion: The longer time to exhaustion for intermittent exercise alternated with passive recovery could be linked to lower metabolic power. As intermittent exercise alternated with passive recovery is characterized by a slower decline in oxyhemoglobin than during intermittent exercise alternated with active recovery at 40% of V̇O2max, it may also allow a higher reoxygenation of myoglobin and a higher phosphorylcreatine resynthesis, and thus contribute to a longer time to exhaustion.
Short intermittent exercises are frequently used in training programs in order to improve maximal oxygen uptake (V̇O2max;19,21,35) and/or anaerobic capacity (35). The performance and physiological adaptations associated with these exercises depend on the interaction between different parameters such as exercise intensity, recovery type, exercise and recovery periods, and number of repetitions. The recovery type, which can be either active or passive, represents one of these variables. For short intermittent exercises, it has been recommended to introduce active recovery between exercises rather than passive recovery in order to decrease blood lactate concentration ([La]b;8,9) and thus to increase time to exhaustion (TTE). This assumption was based on the fact that active recovery enhances blood lactate removal in comparison with passive recovery (11,22,36). However, for short intermittent runs of 15 s at 120% of maximal aerobic speed, alternated with either 15 s of passive recovery or active recovery at 50% of maximal aerobic speed, it has been reported that TTE with passive recovery was longer than with active recovery (18). The latter hypothesized that passive recovery allowed a higher reoxygenation of myoglobin and hemoglobin, and a higher phosphorylcreatine (PCr) resynthesis than active recovery. For short intermittent exercise, oxyhemoglobin (HbO2) variations have already been analyzed using near-infrared spectroscopy (NIRS), and it has been demonstrated that such variations depended on exercise duration and intensity. Christmass et al. (15) reported that the decline in muscle HbO2 during long intermittent exercise (work:recovery ratio of 24s:36s) was significantly greater than for short intermittent exercises (work:recovery ratio of 6s:9s). These results showed that the contrast in HbO2 between the two intermittent exercises was linked to the duration of the work period, as suggested by Åstrand et al. (1) in 1960. Bae et al. (2) found that the deoxygenation level was dependent on exercise intensity, as the decreased oxygenation level was significantly lower in an intermittent exercise at 100% of the power eliciting V̇O2max than during an intermittent exercise at 95% of the ventilatory threshold. However, to our knowledge, no study has focused on the effects of recovery type on the muscle HbO2 variations and its possible influence on the TTE, especially for short intermittent exercises.
This study was designed: 1) to compare TTE using a cycle ergometer for short intermittent exercise (15 s) interspersed with passive recovery (IE-PR) and short intermittent exercise (15 s) interspersed with active recovery at 40% of V̇O2max (IE-AR) and 2) to compare HbO2 variations using NIRS between IE-PR and IE-AR. We hypothesized that TTE would be longer for IE-PR than for IE-AR and that the deoxygenation during IE-PR would be slower than during IE-AR.