Comparing amount of mechanical work and metabolic cost between two kettlebell swing protocols

The kettlebell swing has been touted as having both cardiovascular-driven metabolic and strength benefits which several studies have investigated. However, to the authors’ knowledge, none have researched the work economy of the exercise by capturing both mechanical work and metabolic cost. Here, we implement a commonly studied kettlebell swing protocol consisting of short intervals of 20 reps and 30 seconds of rest and compare it to longer intervals of 60 reps followed by 90 seconds of rest. Work-rest ratio was 1:1 for both protocols based on a consistent cadence (short: 36.75 ± 2.12 vs. long: 37.08 ± 1.66 reps/min) total volume was the same. A group of 6 healthy young adults, familiar with the kettlebell swing, performed both protocols in a counterbalanced order and separated by 20 minutes of rest. To calculate total mechanical work performed (J/kg), we used the Noraxon motion capture system with inertial measurement units (IMUs) and conducted a segmental analysis of the feet, shanks, thigh, pelvis, trunk, upper arms, forearms, hands, and head. Oxygen consumption (VO 2 ) and other metabolic variables were captured using a metabolic cart (Parvo). We hypothesized that longer intervals might challenge form due to muscle fatigue, thereby changing economy despite matched work-rest ratios and total volume. Contrary to our hypothesis, there is no statistical significance in total mechanical work (short: 1043 ± 261 J/kg vs long: 1159 ± 334 J/kg, paired t-test: p = 0.49) between the two protocols. Similarly, total VO 2 (short: 121 ± 14 vs long: 126 ± 15 vs long: mL/kg; paired t-test: p = 0.62) was not significantly different and as a result the total work economy, total VO 2 divided by total work, was also not significantly different (short: 0.122 ± 0.031 ml/J vs long: 0.118 ± 0.043 ml/J; paired t-test: p = 0.34). The present findings suggest that protocols of the same work-rest ratios for the kettlebell swing elicit similar work, metabolic responses and therefore economy, even with different duration intervals. University of Dayton University Honors Program, Berry Summer Thesis Institute This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.