Question

How does training impact O2 deficit and EPOC?

Answer 1

once a workout is over and you’re back in your daily routine, your body’s metabolism can continue to burn more calories then when at complete rest. This physiological effect is called excess post-exercise oxygen consumption, or EPOC. Also known as oxygen debt, EPOC is the amount of oxygen required to restore your body to its normal, resting level of metabolic function (called homeostasis).

When you first start to exercise, your body uses the anaerobic energy pathways and stored ATP to fuel that activity. A proper warm-up is important because it can take about five to eight minutes to be able to efficiently use aerobic metabolism to produce the ATP necessary to sustain physical activity. Once a steady-state of oxygen consumption is achieved, the aerobic energy pathways are able to provide most of the ATP needed for the workout. Exercise that places a greater demand on the anaerobic energy pathways during the workout can increase the need for oxygen after the workout, thereby enhancing the EPOC effect.

Strength training with compound, multijoint weightlifting exercises or doing a weightlifting circuit that alternates between upper- and lower-body movements places a greater demand on the involved muscles for ATP from the anaerobic pathways. Increased need for anaerobic ATP also creates a greater demand on the aerobic system to replenish that ATP during the rest intervals and the post-exercise recovery process. Heavy training loads or shorter recovery intervals increase the demand on the anaerobic energy pathways during exercise, which yields a greater EPOC effect during the post-exercise recovery period.