Performance of Different Accelerometry-Based Metrics to Estimate Oxygen Consumption during Track and Treadmill...

Area of Science:

• Exercise Physiology
• Biomedical Engineering
• Wearable Technology

Background:

• Estimating oxygen consumption (VO2) is crucial for assessing physical activity intensity.
• Accelerometer data offers a promising non-invasive method for VO2 estimation.
• Current methods often rely on specific walking or running protocols to establish relationships between accelerometer metrics and VO2.

Purpose of the Study:

• To compare the predictive performance of three different accelerometer metrics derived from the mean amplitude deviation (MAD) of acceleration signals.
• To evaluate these metrics during maximal exercise tests on both a track and a treadmill.
• To determine the influence of locomotion intensity and test type on VO2 prediction accuracy.

Main Methods:

• Utilized hip-worn triaxial accelerometers and metabolic gas analyzers in 53 healthy adults.
• Collected data during maximal exercise tests conducted on a track (n=29) and a treadmill (n=24).
• Pooled data for statistical analysis to assess the relationship between accelerometer metrics and measured VO2.

Main Results:

• Accelerometer metrics explained 71-86% of VO2 variation at typical walking speeds (VO2 < 25 mL/kg/min).
• For running speeds (VO2 > 25 mL/kg/min), 32-69% of VO2 variation was explained.
• The Mean Amplitude Deviation (MAD) metric was optimal for walking but suboptimal for running, with test type influencing results except for MAD.

Conclusions:

• The choice of accelerometer metric and test type significantly impacts the accuracy of predicting oxygen consumption (VO2).
• MAD is a strong predictor for walking but a weak predictor for running.
• Future research should consider locomotion intensity and test modality for accurate VO2 estimation using accelerometers.