Excess Postexercise Oxygen Consumption After High-Intensity and Sprint Interval Exercise, and Continuous Steady-State...

Area of Science:

• Exercise Physiology
• Metabolic Adaptations

Background:

• High-intensity interval exercise (HIE) and sprint interval exercise (SIE) are anecdotally linked to greater fat loss than continuous steady-state exercise (SSE).
• Excess postexercise oxygen consumption (EPOC) is a potential mechanism for increased fat loss following HIE and SIE.

Purpose of the Study:

• To compare EPOC and energy expenditure (EE) among HIE, SIE, and SSE protocols.
• To determine if EPOC explains the greater fat loss often observed with interval training.

Main Methods:

• Ten recreationally active men completed a randomized crossover study.
• Participants underwent a resting control trial and three exercise conditions: HIE, SIE, and SSE on a cycle ergometer.
• Oxygen consumption (VO2) was measured during and for 3 hours post-exercise to calculate EPOC and net EE.

Main Results:

• 3-hour EPOC and net EE were significantly higher following SIE compared to SSE.
• Total net oxygen consumption and EE (exercise + postexercise) were greater for SSE than for SIE.
• No significant differences in EPOC or EE were found between HIE and either SIE or SSE.

Conclusions:

• EPOC following SIE and HIE is unlikely to be the sole factor driving the greater fat loss reported with these training modalities.
• Continuous steady-state exercise resulted in higher overall energy expenditure despite lower EPOC compared to SIE.