Do moderate- to vigorous-intensity accelerometer count thresholds correspond to relative moderate- to vigorous-intensity physical activity?

• Published in: Applied physiology, nutrition, and metabolism Vol. 44; no. 4; pp. 407 - 413
• Main Authors: Raiber, Lilian, Christensen, Rebecca A.G, Randhawa, Arshdeep K, Jamnik, Veronica K, Kuk, Jennifer L
• Format: Journal Article
• Language: English
• Published: Canada NRC Research Press 01.04.2019; Canadian Science Publishing NRC Research Press
• Subjects: Accelerometers; accelerometry; accélérométrie; activité physique; BMI; Body mass index; condition physique; Evaluation; Exercise; Exercise physiology; fitness; Health; Health surveys; IMC; intensity thresholds; intensité relative; Medical schools; Nutrition; Obesity; Oxygen consumption (Metabolism); physical activity; Physical fitness; Physiological aspects; Physiological research; relative intensity; seuils d’intensité; accelerometry; activité physique; condition physique; intensité relative; fitness; intensity thresholds; seuils d’intensité; relative intensity; IMC; BMI; accélérométrie; physical activity
• ISSN: 1715-5312; 1715-5320
• DOI: 10.1139/apnm-2017-0643

We aimed to predict % maximal oxygen consumption at absolute accelerometer thresholds and to estimate and compare durations of objective physical activity (PA) among body mass index (BMI) categories using thresholds that account for cardiorespiratory fitness. Eight hundred twenty-eight adults (53.5% male; age, 33.9 ± 0.3 years) from the National Health and Nutrition Examination Survey 2003–2004 were analyzed. Metabolic equivalent values at absolute thresholds were converted to percentage of maximal oxygen consumption, and accelerometer counts corresponding to 40% or 60% maximal oxygen consumption were determined using 4 energy expenditure prediction equations. Absolute thresholds underestimated PA intensity for all adults; however, because of lower fitness, individuals with overweight and obesity work at significantly higher percentage of maximal oxygen consumption at the absolute thresholds and require significantly lower accelerometer counts to reach relative moderate and vigorous PA intensities compared with those with normal weight (P < 0.05). However, moderate-to-vigorous physical activity (MVPA) durations were shorter when using relative thresholds compared with absolute thresholds (in all BMI groups, P < 0.05), and they were shorter among individuals with obesity compared with those with normal weight when using relative thresholds (P < 0.05). Regardless of the thresholds used, a greater proportion of individuals with normal weight met the PA guideline of 150 min·week –1 of MVPA compared with individuals with obesity (absolute: 21.3% vs 6.7%; Yngve: 4.0% vs 0.2%; Swartz: 10.7% vs 3.9%; Hendelman: 4.7% vs 0.2%; Freedson: 6.4% vs 0.5%; P < 0.05). Current absolute thresholds of accelerometry-derived PA may overestimate MVPA for all BMI categories when compared with relative thresholds that account for cardiorespiratory fitness. Given the large variability in our results, more work is needed to better understand how to use accelerometers for evaluating PA at the population level.