Biomechanical Analysis of the Kettlebell Swing in Women

Previous research considering kettlebell swings in men demonstrated significant impulse, power, and kettlebell velocity changes with ketttlebell masses varying by 8kg. Women also commonly perform kettlebell swings, however research is needed with smaller load progressions. PURPOSE: To determine the effect of kettlebell mass on peak kettlebell velocity and total body center of mass (TBCM) impulse and peak power in women while performing overhead kettlebell swings. METHODS: 12 women (29.3 ± 6.1 yrs, 69.3 ± 9.6 kg, 1.65 ± .05 m) experienced in kettlebell swings performed 15 overhead swings with three different masses (8 kg, 12 kg, 16 kg) in a between subject randomized order. Participants completed a standardized warm up and were allotted two minutes rest between sets. Three dimensional kettlebell kinematics were used to compute peak kettlebell velocity while TBCM impulse and peak power were computed from the ground reaction forces. Outcome measures were computed as the resultant of vertical and anterior vectors separately during the upswing and downswing. RESULTS: Both impulse and power increased with each load increase. The 12 kg impulse was significantly greater than 8 kg (95% CIdiff: .164 – .354 N•kg-1•s) and 16 kg was significantly greater than 12 kg (95% CIdiff: .325 – .562 N•kg-1•s), while peak power at 16 kg was significantly greater than 8 kg (95% CIdiff: .55 – 11.52 W•kg-1) and 12 kg (95% CIdiff: .15 – 9.6 W•kg-1). There was no significant difference between 8 kg and 12 kg (95% CIdiff: -3.1 – .8 W•kg-1). Concentric kettlebell velocity significantly decreased with each progressive load increase: 12 kg (95%CIdiff: .093 – .296 m•s-1) and 16 kg(95%CIdiff: .145 – .326 m•s-1). Eccentrically the only significant peak velocity difference was between 16 kg and 8 kg (95% CIdiff: .011 – .437 m•s-1). CONCLUSIONS: 4 kg increments in kettlebell mass were sufficient stimulus to largely promote changes in all measures considered. Across the three loads, both impulse and peak power were maximized by the 16 kg despite a significant decrease in velocity. This suggests women with similar kettlebell experience should utilize at least 16 kg to stimulate strength and power adaptations. Future studies examining kettlebell swings in women should consider larger mass kettlebells to determine at what mass impulse and power are maximized