title: Power output in vertical jumps: does optimum loading depend on activity profiles?
abstract: The previously proposed maximum dynamic output hypothesis (MDO: i.e. the optimum load for maximizing the power output during jumping is one's own body) was tested on individuals of various activity profiles. Forty males (10 strength-trained athletes, 10 speed-trained athletes, 10 physically active non-athletes, and 10 sedentary individuals) performed different vertical jumps on a force plate while a pulley system was used to either reduce or increase the subject's body weight by 10-30 %. As expected, an increase in external loading resulted in a significant increase (p < 0.001) in force output and a concomitant decrease of peak jumping velocity in all groups of participants. The main finding, however, was that all groups revealed the maximum peak and mean power output at approximately the subjects' own body weight although their weight represented prominently different percentage of their maximum dynamic strength. While a significant (p < 0.05), albeit moderate, 'group × load' interaction in one jump was observed for the peak power output, the individual optimum load for maximizing the power output number did not differ among the groups. Although apparently further research on various types of movements is needed, the present results provide, so far, the strongest support of the MDO hypothesis.
authors.affiliation: Faculty of Sports and Physical Education, The Research Center, University of Belgrade, Belgrade, Serbia.
authors.forename: Nemanja
authors.initials: N
authors.lastname: Pazin
authors.forename: Bobana
authors.initials: B
authors.lastname: Berjan
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Nedeljkovic
authors.forename: Goran
authors.initials: G
authors.lastname: Markovic
authors.forename: Slobodan
authors.initials: S
authors.lastname: Jaric
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology; D006801:Humans; D008297:Male; D016139:Martial Arts / Q000502:physiology; D008954:Models, Biological; D009043:Motor Activity / Q000502:physiology; D009068:Movement / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D055070:Resistance Training; D057185:Sedentary Behavior; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult