Dooly, C. R., Reed, K. C., & Dotson, C. O. (1997). Excess post-exercise oxygen consumption at different intensities with equal energy expenditure. Medicine and Science in Sports and Exercise, 29(5), Supplement abstract 1113.

This study compared the effects of two exercise conditions of varying intensity and duration but with equal energy expenditure upon excess post-exercise oxygen consumption (EPOC), EPOC magnitude (the caloric cost expended above resting level), EPOC duration (amount of time above resting level), recovery heart rate, and recovery respiratory exchange ratio (RER).

Ss (Females = 15) performed treadmill exercise for either 30 min at 50% VO2max or 21.4 min at 70% VO2max. Duration was adjusted to equalize energy expenditure (197 kcal).

When the 50% and 70% tasks were compared the following were found:

• EPOC accounted for 19.9% and 25.9% of the total energy cost of the exercises,
• EPOC durations were significantly different (15.2 min vs 21.8 min),
• EPOC magnitudes were significantly different (49.0 kcal vs 68.8 kcal), and
• recovery heart rates curves were significantly different.

The slightest modification in the exercise task significantly altered energy requirements.

Implication. This study showed just how specific are the demands for exercise energy. Even though the same amount of work was performed, an alteration in the work characteristics significantly altered the energy demands. Apart from beneficial exercise, training tasks that vary will train different energy delivery mechanisms, magnitudes of energy used, and thus, different levels of performance efficiency/economy.

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