摘要
Purpose The aim of the study was to establish the optimum variable resistance(VR)intensity for loaded countermovement jump(LCMJ)to induce post-activation potentiation(PAP).Methods Eleven male athletes(age 23±2.3 years,height 1.77±0.05 m,body mass 73.7±9.0 kg)attended one familiariza-tion and four testing sessions.Subjects performed their own pre-competition warm up before performing two countermove-ment jumps(CMJ)for baseline measure.Subsequently,they performed 2×3 unloaded(UCMJ)or loaded CMJ(LCMJ)with one of the three VR intensities,Orange(6.7±0.6 kg),Red(14.0±0.9 kg)and Blue(24.0±1.4 kg),in random order,before performing two more CMJ for post-test measure.Each testing session was separated by at least 48 h.Results There was significant increase in jump height in all conditions(P<0.05),but no significant difference in change in jump height between conditions(P>0.05).There were small to moderate effect when comparing Orange and the other conditions.Peak force and velocity increased in Red(P<0.05)and Orange(P<0.05),respectively.Change in jump height was significantly correlated to change in peak velocity(r=0.46,P=0.002)and peak power(r=0.46,P=0.002).Conclusion The findings of the study showed that UCMJ and LCMJ were effective in improving jump height acutely,and an intensity level of about 10%body weight contributed by VR seems to be the optimum resistance level.
