It has been suggested that acute increases in the power output during explosive movements can occur by the prior execution of high intensity resistance exercises. This phenomenon is called Post Activation Potentiation (PAP). One critical factor that is involved in PAP is the length of the recovery period between the intervention and the performance. The isolation of the recovery time as the independent variable has not been successfully achieved previously and there is a need to determine its net effects on the dependent variables measured in PAP studies. To systematically vary the length of the recovery period post hang clean in order to determine the effects of recovery time on performance. Twelve strength-trained male track and field athletes (22.42 ± 5.66 yrs, 1.80 ± 0.07 m, 80.3 ± 8.72 kg) completed 8 randomised protocols with each of them consisting of a structured warm-up, 3 pre standing countermovement vertical jumps, 3 reps of hang cleans set at 90% of 1RM, a variable seated rest and 3 post vertical jumps. The variable rest was set at 0 (T0), 1 (T1), 2 (T2), 3 (T3), 4 (T4), 5 (T5) and 6 (T6) minutes recovery from the hang cleans while a control (C) protocol without the hang clean intervention was also employed. The vertical jumps were performed on a force platform (1000 Hz) and several mechanical variables (e.g. peak power) as well as the jump performance (jump height) were calculated from the force-time curves. A two factor within subjects ANOVA showed no significant changes in any of the mechanical variables in terms of either factor (hang clean, recovery time) or hang clean × recovery time interaction. Regarding the jump height, the post performance remained unchanged for C, T1, T4, T5 and T6 whereas there was a significant decrease (p < 0.05) for T0 (−4%), T2 (−3%) and T3 (−3.3%) (Figure 1). The combination of the selected activation method (3 reps of hang cleans set at 90% of 1RM) and recovery periods may not have activated the necessary neuromuscular mechanisms to enable PAP and consequently increase the vertical jump performance. Moreover the results showed that for most of the shorter recovery periods (T0, T2 and T3) the performance declined. Previous studies which employed similar interventions in terms of volume/intensity have shown positive post activation effects but they used a different type of resistance exercise and a limited number or recovery intervals. The use of a hang clean prior to a vertical jump does not enhance vertical jump performance in university standard athletes. Actually a performance decline can occur if the recovery period between intervention and post performance is short (< 3 min).