The Effects of Weight Training Upon Vertical Jumping Ability

The purpose of this study was to determine which of the following weight training programs would produce the greatest increases in vertical jumping ability: 1. a segmented weight training program that was limited to exercises that strengthen the arms and shoulder girdle. 2. A segmented weight training program that was limited to exercises that strengthen the legs. 3. A program that uses a combination of the exercises used in the two segmented weight training programs. Twenty-seven male college students served as subjects for this study. The vertical jumping ability of each student was measured by a jump- reach variation of the Sargent Jump at the beginning and at the conclusion of a six-week weight training program. All subjects performed their exercises three times a week (Monday, Wednesday, Friday). The subjects were randomly assigned to one of the three groups. Group A (arm and shoulder exercise) performed curls and presses in that order. Group B (leg exercise) performed rise-on-toes and half-squats in that order. Group C (combined exercise) performed curls, presses, rise-on-toes, and half-squats in that order. The vertical jump test consisted of five vertical jump trials for each individual recorded to the nearest half-inch in both the pre- and post-test. The arithmetic mean of the five vertical jump trials was calculated in both and pre- and post-test. Because of the statistically significant F-ratio yielded by the analysis of covariance, the null hypothesis that there was no significant difference among any of the group means could be rejected with a high degree of confidence. In order to determine which mean differences were significant, the t-test was applied. The t-test showed that there was a significant difference between Group A and Group B, between Group A and Group C, but that no significant difference existed between Group B and Group C. The following conclusions were based on the evidence presented in this study: 1. Arm and shoulder weight training exercises do not produce increases in vertical jumping ability. 2. Leg weight training exercises will increase vertical jumping ability. 3. A combination weight training exercise program employing leg exercises and arm and shoulder exercises will increase vertical jumping ability. 4. Leg exercises are significantly superior to arm and shoulder exercises for producing increases in vertical jumping ability. 5. A combination of arm and shoulder and leg exercises is significantly superior to arm and shoulder exercises for increasing vertical jumping ability. 6. A combination of arm and shoulder, and leg exercises are not significantly superior to leg exercises, nor are leg exercises superior to a combination of arm and shoulder exercises, and leg exercises for increasing vertical jumping ability. 7. In a combined exercise program using arm and shoulder exercises (curls and presses) and leg exercises (rise-on-toes and half-squats), the leg exercises appear to be responsible for the increases in vertical jumping ability. 8. For economy of time, coaches should use leg exercises (half-squats and rise-on-toes) to increase vertical jumping ability rather than a combination of exercises (half-squats, rise-on-toes, curls, and presses). However, if there is adequate practice time, it may be desirable to use all of the exercises to improve over-all performance