Previous research has demonstrated that post-activation potentiation (PAP) increases in an intensity-dependent manner. However, these studies did not control for volume loads. The purpose of this study was to investigate the effects of varying intensities and rest period lengths, while controlling for volume load, on vertical jump (VJ) performance. Thirteen men, aged 21 ± 3 years with an average relative full squat of 1.7 ± 2 times their body weight, were recruited for this study. Participants were assigned to 3 different experimental sessions that required them to perform the back squat at 56% (low intensity), 70% (moderate intensity), and 93% (high intensity) of their 1 repetition maximums. Vertical jump height and power were recorded at 0, 2, 4, 8, and 12 minutes after squat. There was a significant condition by time interaction for VJ height and power, in which both variables did not change in the low-intensity condition, whereas decreasing immediately after squat for both the moderate- and high-intensity conditions. In the moderate- and high-intensity conditions, VJ height and power increased and peaked at minute 4 and returned to baseline by minutes 8 and 12. These results indicate that when controlling for total work, jump performance and power are enhanced similarly by moderate and high squat intensities. However, high-intensity workloads may prolong the duration of PAP. Therefore, athletes may use moderate- and high-intensity loads during warm-ups to improve jump performance and power.