A Critical Evaluation of Current Methods for Exercise Prescription in Women and Men

TLDR

Common exercise prescription methods rely on fixed percentages of maximum oxygen uptake, peak work rate, or heart rate. The study aims to compare contemporary gold‑standard prescription methods based on fixed percentages of maximum values with the underutilized domain schema for partitioning exercise intensity. One hundred participants underwent cardiopulmonary ramp tests and submaximal trials to determine V˙O₂max, WR peak, HR max, lactate threshold, and MLSS, which were then used to classify intensity into moderate, heavy, and severe domains. Women showed higher %V˙O₂max and %HR max at lactate threshold and MLSS than men, with wide individual ranges that caused large variability in domain assignment; thus, fixed‑percentage prescription methods poorly match intensity domains and fail to control metabolic stimulus.

Abstract

ABSTRACT Common methods to prescribe exercise intensity are based on fixed percentages of maximum rate of oxygen uptake (V˙O 2max ), peak work rate (WR peak ), maximal HR (HR max ). However, it is unknown how these methods compare to the current models to partition the exercise intensity spectrum. Purpose Thus, the aim of this study was to compare contemporary gold-standard approaches for exercise prescription based on fixed percentages of maximum values to the well-established, but underutilized, “domain” schema of exercise intensity. Methods One hundred individuals participated in the study (women, 46; men, 54). A cardiopulmonary ramp-incremental test was performed to assess V˙O 2max , WR peak , HR max , and the lactate threshold (LT), and submaximal constant-work rate trials of 30-min duration to determine the maximal lactate steady-state (MLSS). The LT and MLSS were used to partition the intensity spectrum for each individual in three domains of intensity: moderate, heavy, and severe. Results V˙O 2max in women and men was 3.06 ± 0.41 L·min −1 and 4.10 ± 0.56 L·min −1 , respectively. Lactate threshold and MLSS occurred at a greater %V˙O 2max and %HR max in women compared with men ( P < 0.05). The large ranges in both sexes at which LT and MLSS occurred on the basis of %V˙O 2max (LT, 45%–74%; MLSS, 69%–96%), %WR peak (LT, 23%–57%; MLSS, 44%–71%), and %HR max (LT, 60%–90%; MLSS, 75%–97%) elicited large variability in the number of individuals distributed in each domain at the fixed-percentages examined. Conclusions Contemporary gold-standard methods for exercise prescription based on fixed-percentages of maximum values conform poorly to exercise intensity domains and thus do not adequately control the metabolic stimulus.