The Effects of Short-Term Resistance Training and Subsequent Detraining on Neuromuscular Function, Muscle Cross-Sectional Area, and Lean Mass

Abstract

PurposeTo examine and compare the effects of three days of dynamic constant external resistance (DCER) and isokinetic (ISOK) training and subsequent detraining on thigh muscle cross-sectional area (TMCSA) and thigh lean mass (TLM), ISOK peak torque (PT), DCER strength, isometric force, muscle activation, and percent voluntary activation (%VA).MethodsThirty-one apparently-healthy untrained men (mean ± SD age = 22.2 ± 4.2 years; body mass = 77.9 ± 12.9 kg; height = 173.9 ± 5.4 cm) were randomly assigned to a DCER training group (n = 11), ISOK training group (n = 10) or control (CONT) group (n = 10). Subjects visited the laboratory eight times. The first visit was a familiarization session, the second visit was a pre-training assessment, the subsequent three visits were for unilateral training of the quadriceps (if assigned to a training group), and the last three visits were the post-training assessments conducted at three days, one week, and two weeks after training ended.ResultsDCER strength increased from pre- to post-training assessment 1 in both limbs for the DCER group only, and remained elevated during post-training assessments 2 and 3 (P < 0.05). In addition, surface EMG for the biceps femoris was higher at post-training assessment 3 than at the pre-training assessment, and post-training assessments 1 and 2 (P < 0.05). No other training-related changes were found.ConclusionThe primary finding of this study was that DCER strength of the trained and untrained limbs can be increased with three days of training. This has important implications for injury rehabilitation, where in the initial period post-injury strength gains on an injured limb can possibly be obtained with short-term contralateral resistance training.