Net Heart Rate for Estimating Oxygen Consumption in Active Adults

Area of Science:

• Exercise Physiology
• Sports Science
• Biomedical Engineering

Background:

• Accurate estimation of oxygen consumption (VO2) is crucial for exercise prescription and energy expenditure calculations.
• Existing methods for VO2 prediction may have limitations in diverse adult populations.
• Net heart rate (netHR), sex, and body mass index (BMI) are readily available metrics during physical activity.

Purpose of the Study:

• To develop and validate a predictive model for net oxygen uptake (netVO2) in active adults during aerobic activities.
• To assess the accuracy of using netHR, sex, and BMI for predicting netVO2.
• To establish a formula for estimating energy expenditure and exercise intensity (METs) based on predicted netVO2.

Main Methods:

• A total of 156 active adults (52 women, 104 men) aged 18-81 participated.
• Participants were divided into a prediction sample (n=79) and a validation sample (n=77).
• Net heart rate (netHR) and net oxygen intake (netVO2) were measured; multiple linear regression and Bland-Altman analysis were used.

Main Results:

• Multiple linear regression revealed that sex, netHR, and BMI significantly predicted netVO2 (R² = 85.2%, p < 0.001).
• The derived formula: NetVO2 = 16 + 3.67 (sex) + 0.27 (netHR) - 0.57 (BMI).
• Bland-Altman plots confirmed good agreement between measured and predicted netVO2, with non-significant differences and trivial effect size.

Conclusions:

• A simple and accurate formula using netHR, sex, and BMI can predict netVO2 in active adults during aerobic exercise.
• The model provides a practical tool for estimating energy expenditure and prescribing exercise intensity (METs).
• This method offers a valuable, non-invasive approach for monitoring and guiding physical activity in clinical and fitness settings.