Do the speeds defined by the American College of Sports Medicine metabolic equation for running produce target energy expenditures during isocaloric exercise bouts?

Abstract

The accuracy of the American College of Sports Medicine (ACSM) equations for producing predicted values of heart rate reserve (HRR) and oxygen uptake reserve (VO2R) and consequently, target energy expenditure (EE) during exercise are yet to be established. This study investigated whether speeds defined by the ACSM metabolic equation for running correctly estimate the EEs during isocaloric exercise bouts. Twenty-eight men performed a ramp-incremental maximal exercise test to determine HRmax and VO2max. Two continuous exercise bouts at 60 and 80% VO2R and target EE of 400 kcal were then performed. In the 60% VO2R exercise the observed VO2R and EE were lower than predicted only during the first time quartile of the bout (t = 6.5, p < 0.001), whereas at 80% VO2R it was lower during the first (t = 15.3, p < 0.001), second (t = 5.4, p < 0.001) and third (t = 3.1, p = 0.025) quartiles. The observed HR was lower than predicted in the first time quartile of the 60% [Formula: see text] (t = 5.6, p < 0.001) and 80% VO2R bouts (t = 10.7, p < 0.001), whereas no significant differences occurred for any other time quartiles (p ≥ 0.23). In conclusion, the running speed defined by the ACSM metabolic equation overestimated VO2R and EE within exercise performed at 60 and 80% VO2R especially in higher intensities.

Influence of exercise modality on agreement between gas exchange and heart rate variability thresholds

“…For example, the relationship between heart rate and ${\dot{\text{V}}\text{O}}_2$ is currently used to estimate the energy expenditure associated with an exercise bout (1,2). However, three recent studies by our group did not confirm the hypothetical 1:1 relationship between the %HRR and $\%{\dot{\text{V}}\text{O}}_2\text{\hspace{0.17em}R}$ during maximal ramp-incremented CPET (24) and prolonged running bouts performed at different constant work rates (25,26). In both activities, the %HRR was greater than the corresponding $\%{\dot{\text{V}}\text{O}}_2\text{\hspace{0.17em}R}$.…”

Acute Hypotensive Response to Continuous and Accumulated Isocaloric Aerobic Bouts

“…Some studies, for example, suggested that accumulated acute exercise may elicit greater PEH than continuous acute exercise [2,3,21,29], while another indicated continuous and accumulated acute exercise bouts elicited similar blood pressure reductions [27]. However, none of those studies applied isocaloric exercise bouts and, therefore, the exercise volume performed may have been a potential confounding factor [9] explaining the inconsistencies in this literature. This is an important methodological issue, since the exercise pressor response, which seems to influence blood pressure after exercise, has been shown to be affected by the total amount of muscle work performed and is a surrogate of exercise volume [5,16].…”

Utility of a Non-Exercise VO2max Prediction Model for Designing Ramp Test Protocols

“…Recently, these methodological issues were addressed by our group using 3 non-exercise models (the second version of VSAQ that was validated by observed VO 2max [22]; Rating of Perceived Capacity (RPC) [27]; and CRF [16]) to predict VO 2max and use as a criterion to determine the final speed of treadmill running ramp protocols in 117 apparently healthy subjects (47 woman) aged between 18 and 51 years [7]. Our previous findings showed that the CRF was more accurate than the VSAQ and RPC for estimating VO 2max [r 2 values ( • ▶ Fig. 3).…”