Effects of low-intensity cycle training with restricted leg blood flow on thigh muscle volume and VO2max in young men

Concurrent improvements in aerobic capacity and muscle hypertrophy in response to a single mode of training have not been reported. we examined the effects of low-intensity cycle exercise training with and without blood flow restriction (bfr) on muscle size and maximum oxygen uptake (vo2max). a group of 19 young men (mean age ± sd: 23.0 ± 1.7 years) were allocated randomly into either a bfr-training group (n=9,bfr-training) or a non-bfr control training group (n=10,con-training),both of which trained 3 days/wk for 8 wk. training intensity and duration were 40% of vo2max and 15 min for the bfr-training group and 40% of vo2max and 45 min for the con-training group. mri-measured thigh and quadriceps muscle crosssectional area and muscle volume increased by 3.4-5.1% (p < 0.01) and isometric knee extension strength tended to increase by 7.7% (p < 0.10) in the bfr-training group. there was no change in muscle size (~0.6%) and strength (~1.4%) in the con-training group. significant improvements in vo2max (6.4%) and exercise time until exhaustion (15.4%) were observed in the bfr-training group (p < 0.05) but not in the contraining group (-0.1 and 3.9%,respectively). the results suggest that low-intensity,short-duration cycling exercise combined with bfr improves both muscle hypertrophy and aerobic capacity concurrently in young men.© journal of sports science and medicine.