Effects of body position in leg-extension exercises on movement-time in a short sprint

Includes bibliographical references (pages 79-86)The purpose of this investigation was to determine the effects of leg-strength gained in two different body positions on movement-time in a ten yard sprint.\ud Forty-eight male students, enrolled in general physical education classes at California State University, Northridge served as subjects. After a one-week orientation period to the training and testing apparatus, the individuals were randomly assigned to one of three groups of sixteen subjects. Group I trained using the Universal Seated Leg-Press exercise, Group II trained using the Marcy Leg-Drive Exercise, and Group III served as a control group.\ud A pre-test was given to each subject for strength in each leg-exercise, and for movement-time in a ten yard sprint, prior to the six-week training period. Training sessions for the experimental groups were conducted each Monday, Wednesday, and Friday during the six-week period. One set of eight to ten repetitions maximum was used by the subjects of the experimental groups for each session. All subjects were retested at the conclusion of the third week of training and again at the completion of the training period. Strength was measured by the 1 RM strength test for both exercises, and movement-time was recorded using an electronic photo-cell and digital clock timer.\ud Analysis of variance on the data of this investigation indicated that all groups significantly improved in strength in both leg-extension exercises. The data on between group differences for the leg-press exercise demonstrated that: 1) Groups I and II improved significantly more than Group III, 2) no significant difference existed between Groups I and II. The data for the leg-drive exercise indicated that: 1) Group II improved significantly more than Groups I and III, 2) no significant difference existed between Groups I and III. (See more in text