Abstract This study attempted to determine if a maximum iosmetric exercise program would improve standing broad jumping ability. Seventy-six male eighth-grade junior high school students were tested in the standing broad jump. The subjects were then paired according to broad jumping ability into two groups. The experimental group participated in an isometric program consisting of a 15-sec. maximum contraction in an inverted leg press once a day, five days a week for six weeks. Both groups were retested at the end of the six weeks program. The data were treated statistically and neither the experimental nor the control group improved significantly in standing broad jumping ability.