High-intensity, short-duration warm-up techniques improve acute physical performance, but sparse research has examined their consequence when followed by intermittent activity, which is pertinent to team sports. The authors compared a 5-repetitionmaximum (5RM) leg-press, a small-sided game (SSG), and a current team-sport warm-up in 10 semiprofessional soccer players after 2 intermittent-activity protocols consisting of 15 repetitions of a 60-s circuit that included sprinting, slalom, walking, jogging, decelerations, changes of direction, backward running, and striding activities. There was a large improvement in countermovement-jump height in the 5RM after the 1st intermittent-activity protocol (mean, ±90% CL 6.0, ±4.0%, P=.03) and a small improvement after the 2nd (4.6, ±4.0%, P=.04) compared with team sport. Reactive agility was moderately faster via 5RM after the 1st intermittent-activity protocol (3.1, ±2.6%: P=.04) and the 2nd (5.7, ±2.7%, P=.001) than via SSG. There was a small improvement in reactive agility after the 1st intermittent-activity protocol in the 5RM, compared with team sport (3.3, ±2.9%, P=.04). There was a small improvement in mean 20-m-sprint times after both intermittent-activity protocols in the 5RM, compared with SSG (4.2, ±2.0%, P=.01, and 4.3, ±2.0%, P=.01) and, after the 1st intermittent-activity protocol only, compared with team sport (4.2, ±2.1%, P=0.02). Small increases in blood lactate concentration were observed (46.7, ±18.6%, P=.01) in the 5RM compared with the SSG after the 2nd intermittent-activity protocol. Improved performances after the 5RM warm-up should encourage practitioners to reduce activity time and include high-intensity tasks in team-sport warmups aimed at inducing a potentiating effect.