BACKGROUND: Resistance training in combination with practical blood flow 
restriction (pBFR) is thought to stimulate muscle hypertrophy by increasing 
muscle activation and muscle swelling. Most previous studies used the KAATSU 
device; however, little long-term research has been completed using pBFR.
OBJECTIVE: To investigate the effects of pBFR on muscle hypertrophy.
METHODS: Twenty college-aged male participants with a minimum of 1 year of 
resistance training experience were recruited for this study. Our study 
consisted of a randomized, crossover protocol consisting of individuals either 
using pBFR for the elbow flexors during the first 4 weeks (BFR-HI) or the second 
4 weeks (HI-BFR) of an 8-week resistance training programme. Direct 
ultrasound-determined bicep muscle thickness was assessed collectively at 
baseline and at the end of weeks 4 and 8.
RESULTS: There were no differences in muscle thickness between groups at 
baseline (P = 0·52). There were time (P<0·01, ES = 0·99) but no condition by 
time effects (P = 0·58, ES = 0·80) for muscle thickness in which the combined 
values of both groups increased on average from week 0 (3·66 ± 0·06) to week 4 
(3·95 ± 0·05) to week 8 (4·11 ± 0·07). However, both the BFR-HI and HI-BFR 
increased significantly from baseline to week 4 (6·9% and 8·6%, P<0·01) and from 
weeks 4 to 8 (4·1%, 4·0%, P<0·01), respectively.
CONCLUSION: The results of this study suggest that pBFR can stimulate muscle 
hypertrophy to the same degree to that of high-intensity resistance training.