The purpose of this study was to asses the effects of isometric, handgrip exercise training at low intensity (15% of maximum voluntary contraction : 15% MVC) on maximum muscle strength, and blood pressure, O₂ supply and O₂ consumption in the brachio-radialis muscles during submaximal isometric handgrip exercise (15% MVC). Twelve female subjects (aged 45~67 years) performed isometric handgrip exercise at 15% MVC for 5 -min. The training frequency was 5 times per week and training period was 10 weeks.
　After training, the maximum handgrip strength increased from 24.5 ± 1.0 kg to 26.4 ± 1.1 kg in trained forearm (P< 0.05), and from 24.0 ± 1.2 kg to 25.6 ± 1.0 kg in untrained forearm (P< 0.05). The number of contration at 30% of pretraining MVC increased not only in the trained forearm (from 65.0 ± 5.7 to 139.3 ± 16.2, P< 0.05), but also in the untrained forearm (from 61.4 ± 4.1 to 110.2 ± 16.1, P< 0.05). After the training, the resting diastolic blood pressure was decreased (P< 0.05), and the systolic and diastolic blood pressure during 5 -min isometric handgrip exercise at 15% MVC tended to decrease. The reduction in oxy-Hb volume during static exercise tended to decrease after training.
　These results suggest that the training of isometric handgrip exercise at low intensity affects the circulatory system and metabolism, not only in the trained arm, but also in the untrained arm.

DESCENTE SPORTS SCIENCE Vol.16/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE