BACKGROUND: Pre-Event movement with weighted objects (PEmWO) to gain a performance advantage is commonly done. The effect that PEmWO has on enhancing performance is unclear. This study's purpose was to investigate the effect PEmWO has on knee extension reaction time (RT) and electromyography (EMG) onset time. METHODS: RT and EMG onset time was measured before and after doing a pre-event movement leg exercise using three weights: 8.90, 17.79, and 26.69 Newtons attached to the participant's shank while the participant extended their leg five times after a random visual 'GO' to move signal. Based on the participant's effort and comfort level, one of these weights was chosen as their baseline. PEmWO exercises were then randomly performed with weighted cuffs of 1/2, equal or 2xs the baseline weight. Each PEmWO consisted of 10 leg extensions with each weight. RT s and EMG onset times were calculated and compared with baseline values. RESULTS: Significant mean differences in RT or EMG onset times were not found among any of the weighted trials. However, in 13% of the participants a substantial increase was observed. CONCLUSIONS: Translating our results to actual athletic performance suggests that weighted PEmWO in most people has no advantage in decreasing the time it takes to initiate a movement. It is suggested when PEmWO exercise is used before an athletic event the lighter weighted object should be used decreasing the possibility of injury. It is also recommended that an assessment be conducted before the event is performed to assure that PEmWO is not having a detrimental effect on the athlete's performance.