This study examined postactivation potentiation (PAP) and its effect on performance during sprint swimming. After maximal muscular contraction, the muscles are in both a potentiated and fatigued state. However, fatigue dissipates faster than potentiation, creating a window of opportunity for possible performance enhancement. We observed 30 collegiate swimmers (15 men and 15 women) performing 2 swim trials in a randomized order. The control trial involved a standard swim warm-up, followed by a 6-minute rest and by a maximal 100-m freestyle swim effort. The PAP trial involved the same protocol; however, a PAP loading protocol involved the subjects completing 4 maximal 10-m swims at a 1-minute interval while attached to a resistive power rack and was completed before the 6-minute rest. Fifty-meter splits and blood lactates were also analyzed. There was a significant improvement in 100-m freestyle swim time (0.54 seconds) for the PAP trial vs. the control trial (p = 0.029). Both men and women improved during the PAP trial compared with the control trial, and there was no significant gender interaction. We conclude that PAP substantially enhances 100-m freestyle performance in collegiate swimmers and presents a valid technique for competitive performance enhancement.