Abstract des Autors

Voluntary and electrically evoked contractile properties were studied in the triceps brachii following a 24-weeks dynamic strength training program in ten men aged 65-78 years. Eight men of a similar age were control subjects. A resistance overload program was undertaken three times per week with subjects performing four sets of six to eight repetitions at 80 of their one repetition maximum (1RM). Maximum voluntary contraction (MVC) and contractile properties were measured at 0, 12, and 24 weeks in the exercise group and at 0 and 24 weeks in the controls. The 1RM was used to assess dynamic strength at 0 and 4 weeks in the exercise group. Contractile measures consisted of supramaximal isometric twitch and post-activation twitch parameters. Muscle size was estimated from anthropometric measurements. Compared with the control group, the exercise group MVC increased by about 20 and time to peak tension was slowed by about 11. Also in the exercise group the peak rate of torque development of the potentiated twitch was reduced by about 10. Twitch potentiation was substantial in both groups (about 140) and unaffected by training. The 1RM increased by about 30, and there was a non-significant positive change of 8.6 in the muscle plus bone cross-sectional area in the exercise group. The results show that the force generating capacity of the triceps brachii in these men can be significantly improved for up to 24 weeks using concentric overload training.