The effects of a high-intensity free-weight back-squat exercise protocol on postural stability in resistance-trained males

摘要

The purpose of this study was to investigate the effects of a high-intensity free-weight back-squat exercise on postural stability characteristics in resistance-trained males. Eighteen college-aged (mean +/- SD: age=22.9 +/- 2.9years; height=175.8 +/- 6.4cm; mass=86.3 +/- 9.3kg), resistance-trained males performed postural stability testing before and after completing five sets of eight repetitions of back-squat exercises at 80% of one-repetition maximum. A commercial balance testing device was used to assess sway index at pre- and at 0, 5, 10, 15 and 20min post-exercise. Each balance assessment consisted of four, 20-s static stance conditions: eyes-open firm surface, eyes-closed firm surface, eyes-open soft surface and eyes-closed soft surface. Sway index was greater (P=0.001-0.020) at Post 0 than at all other time points. No differences (P>0.05) were observed between any other time phases. Sway index was greater (P<0.001) for eyes-closed soft surface than all other conditions. These findings revealed sway index for all conditions significantly increased following completion of the back-squat; however, sway index recovered within 5min of exercise. Higher sway index values as a result of neuromuscular fatigue induced by a back-squat exercise may have performance and injury risk consequences to subsequent activities that rely on postural stability. However, these findings suggest balance impairments may recover in ~5min following high-intensity lower body resistance exercise.