VARIABILITY IN EXPLOSIVE POWER AND EFFECTS OF STATURE DURING THE AGING PROCESS

Abstract

Aerobic performance shows a gradual, but persistent decline as we age. The data is less clear regarding the impact of aging on explosive power. Further, the effects of stature on power performance is unknown. PURPOSE To determine the variability in sport-specific power performance and the influence of stature among young, middle-aged and mature adults. METHODS Jumping ability was quantified using a sports specific protocol. Twelve age groups from 6 to 70+ and both sexes were measured to determine maximum reach height, vertical jump and maximum jumping height (cm). A total of 6,535 subjects were evaluated over the course of two years. The assessment of vertical jump was performed with a basketball suspended from a retractable reel. Subjects were required to grasp the ball at full reach from a flat-footed stance. The height of the ball was raised and recorded electronically to the nearest cm as the subject jumped to grasp and pull down the basketball with two hands. Three trials were given at each height until the subject was unable to successfully retrieve the ball. RESULTS The coefficient of variation (CV) in vertical jump (θ/μ × 100) among youth (6–15) was significantly higher (24%) than among older adolescents and mature males (16%). There was little difference in CV (23%) among age groups in females from 6–70+. The variability was greater among females than males. A low correlation was found to exist between vertical jump and reach height in females (r=.4) and was moderate (r=.68) among males. Among males maximum reach height was highly related to vertical jump (r=.89), but shows only a low relationship among females (r=.39). CONCLUSION The gradual decline in power was accompanied by an equalization among males as they age. This may be due to cessation of training in previously active children. Among females, the variation in explosive power did not change with age and may be explained by less intensive training at an early age, thereby allowing discrepancies that existed in youth to be maintained in adulthood.