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

Abstract

Common methods to prescribe exercise intensity are based on fixed percentages of maximum rate of oxygen uptake (V˙O2max), peak work rate (WRpeak), maximal HR (HRmax). 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˙O2max, WRpeak, HRmax, 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˙O2max 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˙O2max and %HRmax 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˙O2max (LT, 45%–74%; MLSS, 69%–96%), %WRpeak (LT, 23%–57%; MLSS, 44%–71%), and %HRmax (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.

Heart Rate Performance Curve Is Dependent on Age, Sex, and Performance

“…From a practical point of view the heterogenous character of HRPC's has some consequences on exercise prescription when using fixed percentage of HR max , already discussed in detail by our study group (2,12) which was supported recently by Iannetta et al (37). We could nicely show that the same relative intensity of 85% HR max gave different workloads when related to the anaerobic threshold and this effect became even stronger with ß 1 -recepter antagonism application (13).…”

“…Underestimation might cause absence of desired training effects, but overestimation of the workload presents some risks and could have major consequences in subjects suffering from a chronic disease. Iannetta et al (37) supported this earlier results and concluded that "contemporary gold-standard methods for exercise prescription based on fixedpercentages of maximum values conform poorly to exercise intensity domains and thus do not adequately control the metabolic stimulus. "…”

“…Due to the changes of the HRPC pattern with aging, an age dependent prescription of exercise intensity needs to be developed as usual linear equations are not appropriate. The given guideline range of 77-95% HR max (38) to calculate the upper target training limits represent a wide spectrum of cardiorespiratory and metabolic responses (39), so to fulfill the needs for an individualized approach, individual thresholds need to be determined (37).…”

Relationship between maximal incremental and high-intensity interval exercise performance in elite athletes

“…The use of an INC-derived fixed percentage to calculate the HIIT work rate should be considered another determinant of the variability in R lim results in this context. In 2019, Iannetta et al [64] reported that when work rates are set as fixed-percentage of parameters measured at maximal exercise capacity, given the betweensubjects variability in percentages defining the intensity of an exercise domain (i.e., moderate, heavy, severe, extreme [65]), an increased variance in metabolic stimulus/response is expected. In our study, this correlates to metabolic stress and unequal relative work seen in the HIIT participants' responses (e.g., oxygen uptake ranged between 82-91% and 95.4-112% of the individual _ VO 2max during the first and following HIIT repetitions, respectively; Fig 4A).…”

“…In our study, this correlates to metabolic stress and unequal relative work seen in the HIIT participants' responses (e.g., oxygen uptake ranged between 82-91% and 95.4-112% of the individual _ VO 2max during the first and following HIIT repetitions, respectively; Fig 4A). To ensure accurate control of exercise intensity among participants and reduce errors in comparisons, future studies on the physiological response at specific exercise intensity domains should adopt methodological approaches that consider individual physiological thresholds and exercise-intensity domain models as those proposed by Iannetta and colleagues [64].…”