MECHANICAL DEMANDS OF KETTLEBELL SWING EXERCISE
The aims of this study were to establish mechanical demands of kettlebell swing exercise, and provide context by comparing them to mechanical demands of back squat and jump squat exercise. Sixteen men performed two sets of 10 swings with 16, 24, and 32 kg, two back squats with 20, 40, 60 and 80% 1RM, and two jump squats with 0, 20, 40, and 60% 1RM. Sagittal plane motion and ground reaction forces (GRF) were recorded during swing performance, and GRF were recorded during back and jump squat performance. Net impulse, and peak and mean propulsion phase force and power applied to the center of mass (CM) were obtained from GRF data, and kettlebell displacement and velocity from motion data. Results of repeated measures analysis of variance showed that all swing CM measures were maximized during the 32 kg condition, but that velocity of the kettlebell was maximized during the 16 kg condition; displacement was consistent across different loads. Peak and mean force tended to be greater during back and jump squat performance, but swing peak and mean power was greater than back squat power, and largely comparable with jump squat power. However, the highest net impulse was recorded during swing exercise with 32 kg (276.1 ± 45.3 N·s vs. 60% 1RM back squat: 182.8 ± 43.1 N·s, and 40% jump squat: 231.3 ± 47.1 N·s). These findings indicate a large mechanical demand during swing exercise, that could make swing exercise a useful addition to strength and conditioning programs that aim to develop the ability to rapidly apply force.