How Much Is Enough: A Randomized Non-Inferiority Trial Comparing Three Bodyweight Training Protocols

Purpose: The current study tested the hypothesis that a bodyweight training (BWT) protocol with a higher weekly time commitment and training volume would produce greater improvements in cardiorespiratory fitness compared to lower time commitment/volume BWT protocols. Methods: Fifty-eight (n = 21 males; n = 37 females) recreationally active, healthy, young adults were randomized to either a 16 (TAB, n = 20), 27 (5BX, n = 19), or 90 min/week (AMRAP, n = 19) BWT protocol for 6 weeks. Peak work rate (WRpeak) was measured pre- and post-intervention using a cycle ergometer graded exercise test. VO₂peak was estimated (eVO₂peak) using a simple linear regression of WRpeak and VO₂peak generated from a previous study (n = 26; 13M/13F). Results: TAB and 5BX yielded non-inferior improvements in eVO₂peak. The 95% confidence intervals of the mean difference in change did not cross our non-inferiority margin of -2.6 mL/kg/min (TAB-AMRAP = 95% CI = -1.16 to 2.07; 5BX-AMRAP 95% CI = -0.29 to 2.89). Conclusions: Our results suggest that 16 and 27 min/week of minimalist BWT yields non-inferior improvements in CRF compared to 90 min/week and provides evidence supporting the efficacy of low-volume BWT protocols compared to higher volume protocols. The study was registered on Open Science Framework on 29 May 2023 (OSF registration).