Detraining is the
partial or complete loss of training-induced adaptations, in
response to an insufficient training stimulus. Detraining characteristics
may be different depending on the duration of training cessation
or insufficient training.
Mujika I, Padilla S. Detraining: loss of training-induced
physiological and performance adaptations. Part I: short term
insufficient training stimulus. Sports Med. 2000 Aug;30(2):79-87.
Squat strength of Olympic Weightlifters declined approximately
10% in after 4 weeks of cessation of weight training.
Hakkinen K, Komi PV (1985). Changes in electrical and mechanical
behaviour of leg extensor muscles during heavy resistance strength
training. Scandinavian Journal of Sports Science 7: 55-64.
Detraining can result in a decrease in muscle mass.
American College of Sports Medicine. ACSM's Resource Manual
for Guidelines for Exercise Testing and Prescription, 2005
Muscle fiber cross-sectional area declines rapidly in strength
and sprint athletes (during detraining).
Mujika, I and Padillam, S, Muscular characteristics of
detraining in humans. Medicine & Science in Sports &
Exercise. 33(8):1297-1303, August 2001.
Loss of over 24 lbs of muscle after 7 months of detraining.
The effects of detraining on an elite powerlifter. Journal
of Neurological Sciences, 51, 247-257.
Muscle mass returned to pretraining levels after 5 months
Thorstensson, A. Observations on strength training and
detraining. Acta Physiologica Scandinavica 100: 491-493, 1977.
detraining appears to shift the contractile characteristics
towards type IIb, although muscle atrophy is also likely to occur.
Ross A, Leveritt M. Long-term metabolic and skeletal muscle
adaptations to short-sprint training: implications for sprint
training and tapering. Sports Med. 2001;31(15):1063-82.
With detraining, however, muscle cross-sectional area decreases
and there is an increase in the number of oxidative fibres (slow-
twitch) versus glycolytic (fast-twitch) fibres in elite powerlifters
J Appl Physiol 1994; 77:1532-1536