Performance of Different Accelerometry-Based Metrics to Estimate Oxygen Consumption during Track and Treadmill Locomotion over a Wide Intensity Range

Abstract

Accelerometer data can be used to estimate incident oxygen consumption (VO2) during physical activity. Relationships between the accelerometer metrics and VO2 are typically determined using specific walking or running protocols on a track or treadmill. In this study, we compared the predictive performance of three different metrics based on the mean amplitude deviation (MAD) of the raw three-dimensional acceleration signal during maximal tests performed on a track or treadmill. A total of 53 healthy adult volunteers participated in the study, 29 performed the track test and 24 the treadmill test. During the tests, the data were collected using hip-worn triaxial accelerometers and metabolic gas analyzers. Data from both tests were pooled for primary statistical analysis. For typical walking speeds at VO2 less than 25 mL/kg/min, accelerometer metrics accounted for 71–86% of the variation in VO2. For typical running speeds starting from VO2 of 25 mL/kg/min up to over 60 mL/kg/min, 32–69% of the variation in VO2 could be explained, while the test type had an independent effect on the results, except for the conventional MAD metrics. The MAD metric is the best predictor of VO2 during walking, but the poorest during running. Depending on the intensity of locomotion, the choice of proper accelerometer metrics and test type may affect the validity of the prediction of incident VO2.

What Can One Minute of the Day Tell about Physical Activity?

“…The observed U-shaped pattern in relative terms (Figures 5 and 6) also suggests that individuals with high CRF engage in exercise voluntarily and intentionally. However, it is essential to note that the analysis algorithms used in the present study were validated specifically for bipedal activities [23]. As a result, the intensity of activities such as cycling and cross-country skiing may have been underestimated and muscle-strengthening or balance-enhancing activities are not captured properly.…”

“…The raw accelerometer data were analyzed in 6 s epochs according to our standard procedure [23]. For each epoch, the mean amplitude deviation values of the resultant acceleration signal and of the acceleration signal in each orthogonal direction were calculated [23]. The epoch-wise acceleration values were converted to METs [12].…”

“…The epoch-wise acceleration values were converted to METs [12]. The accuracy of the MET estimation is about 1.2 MET for bipedal locomotion over a wide range of speeds [23].…”

Measurement of Sedentary Behavior—The Outcomes of the Angle for Posture Estimation (APE) Method

“…If the MAD value was below 91.5 mg, Equation (4) was used; for MAD values between 91.5 mg and just under 500 mg, Equation (5) was used; otherwise, Equation ( 6) was used. The accuracy of estimation for intensities typical for walking is approximately 0.45 MET and for running it is 1.58 METs [31].…”