Effects of dynamic exercise on muscle function in elderly men, aged 70 years.

Abstract

The maximal electrically evoked and voluntary contractions of the triceps surae were measured, before and after 30 min of continuous uphill walking, in 8 elderly men aged 67-71 years. The exercise was performed on a motor-driven treadmill and corresponded to 66-74% of their predicted maximal aerobic power output. During the control period, before exercise, twitch tension (Pt), time-to-peak tension (TPT) and half relaxation time (1/2RT) of the maximal twitch response were 102 +/- 29 N, 156 +/- 15 ms and 98 +/- 11 ms; the tetanic responses at frequencies of 10 Hz (PO10) and 20 Hz (PO20) and the maximal voluntary contraction (MVC) averaged 600 +/- 103, 766 +/- 106 and 1,225 +/- 185 N, respectively. The fatigue index in response to a 2-min test involving repeated tetanisation of the triceps surae was 0.40 +/- 0.14. None of these variables (except TPT which was decreased to 145 +/- 11 ms, p less than 0.001) was significantly changed following exercise. It was concluded that exercise of relatively high intensity and duration in healthy elderly men does not impair the force-generating capacity of the lower leg muscles nor increase their fatigability.