In this prospective, single-center, randomized, self-controlled crossover manikin simulation study, participitants performed 2 minutes of single-rescuer CPR (30:2 compression-to-ventilation ratio) with each of the four techniques (the two-finger (2F), three-finger (3F), heel-of-one-hand (HOH), and two-thumb (2T) techniques) in a randomized order, with at least 10 minutes of rest between techniques. Chest compression depth, rate, release velocity, and the proportion of compressions within the target range were recorded using a feedback device. Provider fatigue and perceived difficulty (modified Borg scale) were assessed as secondary outcomes