Introduction: According to current guidelines, the intensity of health-enhancing aerobic exercise should be prescribed using a percentage of heart rate reserve (%HRR), which is considered to be more closely associated (showing a 1:1 relation) with the percentage of oxygen uptake reserve (%V̇O2R) rather than with the percentage of maximal oxygen uptake (%V̇O2max) during incremental exercise. However, the associations between %HRR and %V̇O2R and between %HRR and %V̇O2max are under debate; hence, their actual relationships were investigated in this study. Methods: Data from each stage of a maximal incremental exercise test performed by 737 healthy and physically inactive participants of the HERITAGE Family Study were screened and filtered, then used to calculate the individual linear regressions (ILR) between %HRR and either %V̇O2R or %V̇O2max. For each relationship, the mean slope and intercept of the ILRs were compared to 1 and 0 (i.e., the identity line), respectively, using one-sample t-tests. The individual root mean square errors (RMSE) of the actual vs. the 1:1 predicted %HRR were calculated for both relationships and compared using a paired-sample t-test. Results: The mean slopes (%HRR-%V̇O2R: 0.972±0.189; %HRR-%V̇O2max: 1.096±0.216) and intercepts (%HRR-%V̇O2R: 8.855±16.022; %HRR-%V̇O2max: −3.616±18.993) of both relationships were significantly different from 1 and 0, respectively, with high inter-individual variability. The average RMSEs were high and revealed that the %HRR-%V̇O2max relationship was more similar to the identity line (p<0.001) than the %HRR-%V̇O2R relationship (7.78±4.49% vs. 9.25±5.54%). Conclusions: Since both relationships are different from the identity line and using a single equation may not be appropriate to predict exercise intensity at the individual level, a re-thinking of the relationships between the intensity variables may be necessary to ensure that the most suitable health-enhancing aerobic exercise intensity is prescribed.
HRR and V̇O₂R fractions are not equivalent: Is it time to rethink aerobic exercise prescription methods?
Stocchi, Vilberto;
2021-01-01
Abstract
Introduction: According to current guidelines, the intensity of health-enhancing aerobic exercise should be prescribed using a percentage of heart rate reserve (%HRR), which is considered to be more closely associated (showing a 1:1 relation) with the percentage of oxygen uptake reserve (%V̇O2R) rather than with the percentage of maximal oxygen uptake (%V̇O2max) during incremental exercise. However, the associations between %HRR and %V̇O2R and between %HRR and %V̇O2max are under debate; hence, their actual relationships were investigated in this study. Methods: Data from each stage of a maximal incremental exercise test performed by 737 healthy and physically inactive participants of the HERITAGE Family Study were screened and filtered, then used to calculate the individual linear regressions (ILR) between %HRR and either %V̇O2R or %V̇O2max. For each relationship, the mean slope and intercept of the ILRs were compared to 1 and 0 (i.e., the identity line), respectively, using one-sample t-tests. The individual root mean square errors (RMSE) of the actual vs. the 1:1 predicted %HRR were calculated for both relationships and compared using a paired-sample t-test. Results: The mean slopes (%HRR-%V̇O2R: 0.972±0.189; %HRR-%V̇O2max: 1.096±0.216) and intercepts (%HRR-%V̇O2R: 8.855±16.022; %HRR-%V̇O2max: −3.616±18.993) of both relationships were significantly different from 1 and 0, respectively, with high inter-individual variability. The average RMSEs were high and revealed that the %HRR-%V̇O2max relationship was more similar to the identity line (p<0.001) than the %HRR-%V̇O2R relationship (7.78±4.49% vs. 9.25±5.54%). Conclusions: Since both relationships are different from the identity line and using a single equation may not be appropriate to predict exercise intensity at the individual level, a re-thinking of the relationships between the intensity variables may be necessary to ensure that the most suitable health-enhancing aerobic exercise intensity is prescribed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.