2019 年 19 巻 2 号 p. 114-121
Resistance training (RT) machines are very useful devices for muscle hypertrophy and muscle strengthening. However, RT machines have friction resistance. It causes decrease in lowering movement load and increase in lifting load. The present study was performed to examine how to decrease load in lowering movement compared to lifting movement in RT machines. Low rowing and arm curl were performed as representative RT events in heavy (10 repetition maximum [10RM] load), middle (heavy×0.7) and low (heavy×0.7×0.7) load condition and in normal (1s lifting / 1s lowering), moderate slow (2s lifting /2s lowering) and slow (3s lifting / 3s lowering) movement speed. RT events in several conditions were performed with free weight (FW), gymnastic RT machine (GM) and home use RT machine (HM). The rates of lowering movement phase load compared to lifting movement phase load (ECC/CON: eccentric/concentric) were approximately 100% in FW,88-96% in GM and 51-65% in HM. The decreasing rates in lowering movement in GM and HM were affected a little by movement speed or training load. These results suggest that the decreasing rate in lowering movement in GM is not large, but that in HM is considerably large.
