Expansion
Excess post-exercise oxygen consumption repays stores and restores homeostasis
Expansion
At the start of exercise, oxygen uptake lags behind demand, creating an oxygen deficit met by anaerobic sources.
After exercise, oxygen consumption remains above resting for minutes to hours: excess post-exercise oxygen consumption.
It is used for:
- Resynthesis of phosphocreatine and ATP (the fast component, minutes)
- Replenishing oxygen bound to myoglobin and haemoglobin
- Lactate clearance and conversion to glucose in the liver (the Cori cycle)
- Restoring body temperature, heart rate and ventilation
- Elevated catecholamines and increased metabolic rate
- Repair and remodelling of tissue
The fast component lasts minutes; the slow component may persist for hours after prolonged or high-intensity work.
This explains why high-intensity interval training produces a greater total energy expenditure than the exercise session alone would suggest, and why recovery heart rate and ventilation take time to normalise even after brief maximal effort.