Effect of individual characteristics and aerobic training on the %HRR‐%V̇O₂R relationship

Abstract

This study aimed to assess if, during incremental exercise, considering individual characteristics can make the relationship between the percentages of heart rate (HRR) and oxygen uptake (V ̇O2R) reserve either 1:1 or more accurate. Cycle ergometer data of the maximal incremental exercise tests performed by 450 healthy and sedentary participants (17-66 years) of the HERITAGE Family Study, grouped for sex, ethnicity, age, body fat, resting HR, and V ̇O2max, were used to calculate the individual linear regressions between %HRR and %V ̇O2R. The mean slope and intercept of the individual linear regressions of each subgroup were compared with 1 and 0 (identity line), respectively, using Hotelling tests followed by post-hoc one-sample t-tests. Two multiple linear regressions were also performed, using either the slopes or intercepts of the individual linear regressions as dependent variables and sex, age, resting HR, and V ̇O2max as independent variables.The mean %HRR-%V ̇O2R relationships of all subgroups differed from the identity line. Moreover, individual linear regression intercepts (8.9±16.0) and slopes (0.971±0.190) changed (p<0.001) after 20 weeks of aerobic training (13.1±11.1 and 0.891±0.122). The multiple linear regressions could explain only 3.8% and 1.3% of the variance in the intercepts and slopes, whose variability remained high (standard error of estimate of 15.8 and 0.189). In conclusion, the %HRR-%V ̇O2R relationship differs from the identity line regardless of individual characteristics and their difference increased after aerobic training. Moreover, due to the high interindividual variability, using a single equation for the whole population seems not suitable for representing the %HRR-%V ̇O2R relationship of a given subject, even when several individual characteristics are considered. HIGHLIGHTS The association between %HRR and %V ̇O2R is not 1:1 even when individuals are grouped by age, sex, ethnicity, body composition, HRrest, and V ̇O2max. Using several subject characteristics to identify the individual's %HRR-%V ̇O2R relationship does not meaningfully increase its prediction accuracy or reduce the interindividual variability of %HRR-%V ̇O2R relationships  Using a single equation for the whole population is not suitable for representing the relationship of a given subject; hence, individual relationships should be preferred when prescribing the intensity of aerobic exercise. The individual %HRR-%V ̇O2R relationship should be periodically assessed due to the potential training induced changes in the relationship.

Factors Determining the Agreement between Aerobic Threshold and Point of Maximal Fat Oxidation: Follow-Up on a Systematic Review and Meta-Analysis on Association

“…The traditional approach used to prescribe and monitor exercise intensity is based on the use of physiological parameters, such as oxygen uptake (VO 2 ) or heart rate (HR), expressed either in absolute (e.g., mL/kg/min and beats per minute (b/min), respectively) or relative (e.g., percentages of their maximal values, %VO 2max and %HR max , respectively) values [13]. Although these methods are commonly used and widely accepted by the scientific community, they have been shown to produce a high inter-individual variability in exercise intensity [15]. Indeed, the high inter-individual variability in the metabolic responses resulting from exercise prescription methods based on fixed percentages of maximum values yielding FAT max and 45-65%HR max ) has been revealed [1,8,16].…”

An Evaluation of Change in the Physical Output in Female Youth Football Players During a Game

“…During exercise, HR is used as an index of the physical load because HR is related to V ̇O2 during dynamic exercise (Marini et al, 2022). Some studies (Ali & Farrally, 1991;Mohr et al, 2004) have attempted to assess physical strength during a football game using HR and demonstrated that the average percentage of the maximal HR (%HRmax) during a 90-min soccer match is close to the anaerobic threshold (80%-90% of %HRmax in soccer players) (Stolen et al, 2005).…”

Are incremental exercise relationships between rating of perceived exertion and oxygen uptake or heart rate reserve valid during steady-state exercises?

“…After 3 min, necessary to reach HRs close to the desired intensity ( i.e., 60% and 80% HRR), the speed was adjusted (when needed) every 30s to find the speed yielding the desired target %HRR, which was then used as starting exercise intensity of the SSEs. The practice trials allowed a more accurate determination of the speed yielding the desired HR, which could have been biased by the lack of the 1:1 relationship between %HRR and %V̇O 2 R ( Ferri Marini et al, 2022a ; Ferri Marini et al, 2021b ; Ferri Marini et al, 2023 ) or the presence of errors in the ACSM’s running equation. The practice trials were intended to last less than 12 min to avoid possible altered HR responses due to the onset of cardiovascular drift ( Wingo, 2015 ).…”

“…However, the relationships between RPE and HR, V̇O 2 , or blood lactate ( Borg, Hassmen & Lagerstrom, 1987 ; Borg, 1974 ; Dunbar et al, 1992 ; Glass, Knowlton & Becque, 1992 ; Irving et al, 2006 ; Noble et al, 1983 ; Robertson et al, 2004 ; Utter et al, 2004 ) were found during incremental exercises but are used to prescribe and monitor exercise intensity during prolonged constant-intensity exercises. Additionally, there is a high interindividual variability in the relationship between %HRR and %V̇O 2 R ( Ferri Marini et al, 2023 ), which makes the use of standardized values for the entire population potentially inaccurate at an individual level. Indeed, ACSM guidelines ( ACSM, 2012 ; ACSM, 2021 ) point out that the RPE responses across exercise modalities and individuals are not comparable due to the high interindividual variability.…”