Whole Body Fat Free Mass and Vo2peak in Recreationally Active Men and Women

Abstract

BACKGROUND: Vo2peak has traditionally been thought to be regulated by cardiac output and arteriovenous-oxygen difference. A “muscle-centric” view suggests the cardiovascular system is secondarily responsive to the primary driver: active muscle mass.METHODS: A total of 19 recreationally active men (N = 10) and women (N = 9) performed a Vo2peak test, a Vo2peak verification test on an electrically braked cycle ergometer on the same day, and a hydrostatic weighing test to assess fat free mass after providing written informed consent.RESULTS: Vo2peak was significantly higher in men (3.74 ± 0.6 L · min−1) than women (2.22 ± 0.30 L · min−1). Whole body fat free mass explained 91% of the variability in Vo2peak (R2 = 0.91) in the men and women combined, 81% of the variability in Vo2peak in men alone, and 46% of the variability in Vo2peak in women alone. None of these subjects were highly trained.DISCUSSION: Fat free mass, a surrogate for muscle mass, was the primary predictor of Vo2peak in this group of recreationally active men and women. Therefore, it appears that whole body fat free mass (a surrogate for muscle mass) is the primary driver for Vo2peak in these recreationally active men and women. These data have implications as to the type of training NASA personnel should be undertaking: resistance training as opposed to aerobic training.Lambert CP. Whole body fat free mass and Vo2peak in recreationally active men and women. Aerosp Med Hum Perform. 2020; 91(2):102–105.