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

Common methods to prescribe exercise intensity are based on fixed percentages of maximum rate of oxygen uptake (VO_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 VO_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 VO_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 %VO_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 %VO_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.