Detraining

Detraining is the partial or complete loss of physiological and performance adaptations previously gained through exercise training because the training stimulus has been substantially reduced or stopped. It can occur during periods of injury, illness, inactivity, or planned breaks from regular training. The extent of detraining depends on factors such as the duration and degree of training reduction, the type of adaptation, and the person’s previous training status .^1,2

Cardiorespiratory adaptations can begin to regress within weeks of training cessation. In endurance-trained individuals, detraining can reduce maximal oxygen uptake, partly through decreases in blood and plasma volume and changes that reduce maximal stroke volume and cardiac output. Metabolic adaptations, including skeletal-muscle oxidative capacity and glycogen storage, can also decline as an insufficient training stimulus continues .^1,2

Other training adaptations can also be lost during detraining, and different characteristics do not necessarily decline at the same rate. Strength, power, endurance capacity, and cardiovascular fitness can therefore follow different time courses. Some adaptations may remain above pre-training levels even after measurable declines have occurred .^1,2

Detraining is distinct from tapering and ordinary recovery. A taper is a deliberate short-term reduction in training load designed to reduce accumulated fatigue while preserving training adaptations and improving readiness for performance. Detraining refers specifically to the loss of training-induced adaptations when the remaining training stimulus is insufficient to maintain them .^1,3