(13) COMPARISON OF REALTIVE MEAN CONCENTRIC FORCE, DURATION, AND IMPULSE BETWEEN FLYWHEEL AND TRADTIONAL SQUATS

Abstract Details:

Purpose: The purpose of this study was to compare the propulsion force-time characteristics between traditional back squats and flywheel inertial squats.

Methods: 17 resistance-trained individuals including nine men (age = 24.7 ± 4.0 years, height = 171.7 ± 5.8 cm, body mass = 77.9 ± 11.2 kg, relative one repetition maximum [1RM] back squat = 2.01 ± 0.26 kg/kg) and eight women (age = 23.0 ± 2.1 years, height = 167.6 ± 8.6 cm, body mass=71.5 ± 7.7 kg, relative 1RM back squat = 1.43 ± 0.25 kg/kg) participated in three separate testing sessions. The first session required the subjects to complete a 1RM back squat protocol and flywheel squat familiarization. The order of the following sessions was randomized and required the subjects to perform either traditional back squat or flywheel inertial squat sets. Specifically, subjects performed three repetitions each of 40, 50, 60, 70, and 80 of their 1RM back squat or five flywheel squats using 0.01, 0.025, 0.050, 0.075, and 0.10 kgm2 inertial wheels. It should be noted that only the last three repetitions of each flywheel set were used for statistical analysis. Each squat repetition was performed on dual force plates sampling at 1000 Hz and the raw force-time data were used to calculate propulsion mean force, phase duration, and impulse. A series of 2 (condition) x 5 (load) repeated measures ANOVA tests were used to examine the differences between squat conditions. In addition, Hedge’s g effect sizes were used to examine the magnitude of the differences for each variable.

Results: There were significant condition x load interaction effects for propulsive mean force, duration, and impulse (all p < 0.001). Descriptive statistics and post hoc comparisons are displayed in Table 1. Large effect sizes (g=1.20-1.52) favored traditional squats across all loads for propulsive mean force. Despite a trivial difference (g=0.03) at 40% 1RM/0.01 kgm2, there were large-very large (g=1.60-2.63) differences were present between conditions across the remaining loads for propulsion phase duration. Finally, the differences between conditions for propulsion impulse were moderate-large (g=0.65-1.92) with larger impulses being produced by flywheel squats with all loads except the lightest.

Conclusions: Greater propulsion forces were produced during traditional back squats across all the examined loads. In contrast, propulsion phase durations and impulses were greater for flywheel squats at all but the lightest load. PRACTICAL APPLICATIONS: Traditional back squats may provide a superior training stimulus for propulsive rapid force production as greater forces are produced over shorter durations across the entire loading spectrum. However, flywheel squats may be used to train individuals to create large propulsive impulses. Practitioners should note that the examined traditional and flywheel loads may not be direct equivalents and thus, further research is needed to determine what loads may correspond with each other.

Acknowledgements: None