Effects of short-term detraining following blood flow restricted low-intensity training on muscle size and strength

We investigated the effects of 3 weeks of detraining on muscle cross-sectional area (CSA) and one-repetition maximum strength (1-RM) in young men who had previously participated in 6 weeks (3 days week(-1) ) of bench press training [blood flow restricted low-intensity (LI-BFR; n = 10, 20% 1-RM) or high-intensity (HI; n = 7, 75% 1-RM)]. Bench press 1-RM and muscle CSA of triceps brachii (TB) and pectoralis major (PM) were evaluated before (pre) and after training period (post) as well as after detraining period (detraining). Bench press 1-RM was higher at both post and detraining than at pre for LI-BFR (P<0·01) and the HI (P<0·01). TB and PM muscle CSA were higher at both post and detraining than at pre for the HI group (P<0·01), while the LI-BFR group only increased (P<0·01) at post. Relative dynamic strength (1-RM divided by TB muscle CSA) was higher at both post and detraining than at pre for the HI group (P<0·01), while the LI-BFR group only increased (P<0·01) at detraining. In conclusion, increased muscle strength following 6 weeks of training with LI-BFR as well as HI was well preserved at 3 weeks of detraining. HI-induced muscle strength appears to be dependent upon both neural adaptations and muscle hypertrophy with training and detraining. On the other hand, LI-BFR-induced muscle strength appears to be related primarily to muscle hypertrophy with training and to neural adaptations with detraining.