Resistance exercise is recommended by the major health and sports medicine organizations to maintain good health, but resistance exercise energy expenditure is difficult to measure. Accelerometers offer a viable alternative to estimate energy expenditure during resistance exercise because they are cost effective and do not restrict motion or exercise choice.
Purpose: To estimate resistance exercise energy expenditure using accelerometry and to determine whether there are differences in counts of activity during resistance exercise on the basis of accelerometer location.
Methods: Thirty men and women (21.6 yr) performed two sets of 10 repetitions of each of eight exercises. During the exercise protocol, participants wore accelerometers (ActiGraph GT1M) on the wrist, waist, and ankle and a portable metabolic system (CosMed K4b2).
Results: Activity counts (mean ± SD) were different between the wrist (61,282 ± 8358), the ankle (26,886 ± 3998), and the waist (6565 ± 2445). Resistance exercise energy expenditure was significantly associated with ankle (r = 0.50; P < 0.01) and waist (r = 0.77; P < 0.001) accelerometer counts, and there was a trend for an association between resistance exercise energy expenditure and wrist accelerometer counts (r = 0.31; P = 0.10). Total waist accelerometer counts explained 59% of the variance (R2 = 0.59) in energy expenditure. A regression equation to predict resistance exercise energy expenditure including sex, fat-free mass, and counts of activity from the waist accelerometer explained 90% (R2 = 0.90) of the variance in energy expenditure.
Conclusion: Resistance exercise energy expenditure can be estimated using a uniaxial accelerometer worn at the waist, along with the sex, and fat-free mass, of the participant.