Abstract

The purpose of this study was to examine mode and speed specificity of strength training by comparing concentric and eccentric isokinetic exercise of the quadriceps. Forty-eight healthy men (mean age = 23.9 years) were randomly assigned to one of three groups: concentric training (C), eccentric training (E), or control (K). Average force (in Newtons) of 3 concentric and of 3 eccentric quadriceps contractions on the KIN-COM dynamometer at 60, 120, and 180 degrees/sec was evaluated prior to and following a 6 week period during which only the C and E groups trained. Training sessions (3/week) included 4 submaximal and 1 maximal warm-up followed by 10 maximal effort isokinetic contractions of the quadriceps at 120 degrees/sec for each leg. Group C subjects trained concentrically only while Group E subjects trained eccentrically only. A t-test for independent means showed no significant right/left differences. ANOVA and Scheffes F-tests were then used to assess the differences in training effects among the 3 groups for the left leg only. Results showed that although Group C increased slightly in both concentric and eccentric force at all speeds, the gains were significant only for concentric force at 180 degrees/sec. Group E showed significant gains in eccentric force at all speeds but not in concentric force. The K group had no significant change in concentric or eccentric force at any speed. Verf.-Referat