Distinguishing Increased Adiposity and/or Aerobic Deconditioning as Moderators of Low VO2peak in Obese Men

Authors

Jeff M. Moore, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterFollow
Carrie Ferguson, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterFollow
Molly M. Baldwin, Centre for Exercise and Rehabilitation Science, NIHR Leicester Biomedical Research CentreFollow
Ronald S. Swerdloff, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterFollow
Christina Wang, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterFollow
Wei Yan, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterFollow
Harry B. Rossiter FACSM, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterFollow

Abstract

Peak oxygen uptake (V̇O_2peak) in a cardiopulmonary exercise test (CPET) is a strong predictor of morbidity, mortality, and quality of life. V̇O_2peak in obese individuals is typically below the lower limit of normal (2 transport and utilization, i.e. aerobic deconditioning; or both. We hypothesized a modified CPET, to measure the fraction of maximum isokinetic power that can be supported by aerobic metabolism, will distinguish between adiposity and deconditioning effects on V̇O_2peak. PURPOSE: To compare V̇O_2peak and isokinetic neuromuscular performance in obese vs non-obese men. METHODS: A modified CPET with maximal (3 s) isokinetic cycling power at baseline and the limit of ramp-incremental (RI) exercise was used to calculate: A) baseline maximum isokinetic power (Piso); B) tolerance index (TI), % of Piso at V̇O_2peak; C) fatigue index (FI), % reduction in Piso per RI-watt at V̇O_2peak; D) power reserve (PR), isokinetic power available at V̇O_2peak expressed as % RI-watt_peak. The FRIEND nomogram was used to predict V̇O_2peak. Data are mean(SD) and were assessed by t-test. RESULTS: Compared to controls (n=24), obese men (n=20) were older (32(5) vs 26(7) yr), had greater BMI (38(6) vs 23(2) kg/m²), but were not different in stature (177(5) vs 180(7) cm) or predicted V̇O_2peak (3.49(0.49) vs 3.58(0.36) L/min). Obese men had lower V̇O_2peak (2.84(0.42) vs 3.71(0.45) L/min, p2peak (82(15) vs 104(12) %, pIndependent of body mass, obese men had preserved leg strength (normal Piso), but the fraction of maximum isokinetic power supported by aerobic metabolism at RI intolerance was reduced (low TI) with greater fatigability (high FI); each consistent with aerobic deconditioning. A modified CPET with maximal isokinetic power measurements can distinguish the effects of increased adiposity from aerobic deconditioning on V̇O_2peak in obese men.

Recommended Citation

Moore, Jeff M.; Ferguson, Carrie; Baldwin, Molly M.; Swerdloff, Ronald S.; Wang, Christina; Yan, Wei; and Rossiter, Harry B. FACSM (2022) "Distinguishing Increased Adiposity and/or Aerobic Deconditioning as Moderators of Low VO2peak in Obese Men," International Journal of Exercise Science: Conference Proceedings: Vol. 14: Iss. 2, Article 150.
Available at: https://digitalcommons.wku.edu/ijesab/vol14/iss2/150