Abstract

The purpose of this study was to observe the effects of 2 intense exercise programs, emphasizing frequency, on the contractile enzyme of human skeletal muscle. Ten female subjects were randomly assigned to either a high frequency (H) (120 rpm) or low frequency (L) (60 rpm), bicycle ergometer training program. Throughout the 6 week program, each subject trained 3 d/wk, by performing 10, 20 sec. exercise bouts at the same relative intensities (1.5 x V02 MAX). Each week 1 bout and 10 of the initial V02 MAX were added to both groups. Before and after training a frequency (F) and resistance (R) power test were administered and muscle biopsies obtained. The power production (kpm/sec/kg) of the R and F tests increased as a result of both training programs, with differences between groups not significant. Increments in myofibrillar ATPase activities were 0.181 +/- 0.023 to 0.272 +/- 0.22 umoles Pi/mg/min and 0.214 +/- 0.022 to 0.244 +/- 0.018 umoles Pi/mg/min for the H and L groups, respectively. No changes in muscle glycogen, ATP and CP were observed. The results for change in ATPase activity suggest that movement frequency is not a critical factor for determining biochemical characteristics of human muscle. Verf.-Referat