Five monozygotic twin pairs were submitted to a 10-week isokinetic strength training program and biochemical characteristics measured before and after training to determine the role of heredity in skeletal muscle adaptation, while 5 unrelated sedentary subjects served as control group. Experimental subjects performed twice 3 series of 5 bilateral reciprocal alternating knee flexions and extensions at a velocity of 90 °/s 5 times per week. Before and after the training period, for each subject, the peak muscular torque output was measured at the same velocity and the vastus lateralis muscle was biopsied for biochemical determinations. No significant change was observed in the control group. Training increased peak muscular torque output by 24%. The activities of hexokinase, malate dehydrogenase and 3-hydroxyacyl CoA dehydrogenase also increased significantly by 28, 26 and 38%, respectively. Interindividual variations in the response of these variables to training were noted but these were shown to be independent of the genotype. No overall effect of training was observed for oxoglutarate dehydrogenase activity (OGDH). However, changes were seen in individual pairs of twins and these were in opposite directions in some pairs compared to others, thus explaining the absence of a general training effect. Significant intrapair resemblance in the training response was present for OGDH (r = 0.76), indicating that the sensitivity to isokinetic strength training for OGDH was highly variable, not random and probably genetically determined.
The effects of variations in extent of movement on fractionated reaction times (RTs) were studied in 18 male Ss. The means of total RT, premotor RT and motor RT (Weiss, 1965) did not change significantly under the two treatment conditions involving variations in extent of elbow flexion in response to a visual stimulus. These results supported earlier work of Brown and Slater-Hammel (1949), but apparently conflicted with recent data reported by Williams (1971). A differential effect of practice on the two tasks was identified and postulated as a possible factor contributing to the conflict among previous research findings.
This study was designed to investigate the influence of functional electrical stimulation on the improvement of reaction time and its fractionated components during learning an horizontal arm-sweep task. 62 subjects participated and were divided into control, stimulation, and trail/stimulation groups. Functional electrical stimulation was an effective method of improving total reaction time and its central component, premotor time.
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