Effects of resistance exercise combined with moderate vascular occlusion on muscular function in humans

Acute and long-term effects of resistance exercise combined with vascular o cclusion on muscular function were investigated. Changes in integrated elec tromyogram with respect to time (iEMG), vascular resistive index, and plasm a lactate concentration were measured in five men either during or after el bow flexion exercises with the proximal end of the arm occluded at 0-100 mm Hg. The mean iEMG, postexercise hyperemia, and plasma lactate concentration were all elevated with the increase in occlusion pressure at a low-intensi ty exercise, whereas they were unchanged with the increase in occlusion pre ssure at high-intensity exercise. To investigate the long-term effects of l ow-intensity exercise with occlusion, older women (n = 24) were subjected t o a 16-wk exercise training for elbow flexor muscles, in which low-intensit y [similar to 50-30% one repetition maximum (1 RM)] exercise with occlusion at similar to 110 mmHg (LIO), low-intensity exercise without occlusion (LI ), and high- to medium-intensity (similar to 80-50% 1 RM) exercise without occlusion (HI) were performed. Percent increases in both cross-sectional ar ea and isokinetic strength of elbow flexor muscles after LIO were larger th an those after LI (P < 0.05) and similar to those after HI. The results sug gest that resistance exercise at an intensity even lower than 50% 1 RM is e ffective in inducing muscular hypertrophy and concomitant increase in stren gth when combined with vascular occlusion.