Estimation of resistance exercise energy expenditure using triaxial accelerometry

Area of Science:

• Exercise Physiology
• Biomechanics
• Wearable Technology

Background:

• Previous research indicated uniaxial accelerometers can estimate resistance exercise energy expenditure.
• Resistance exercise involves multi-planar movements, suggesting triaxial accelerometers might offer improved accuracy.
• Optimal placement of triaxial accelerometers for this purpose requires investigation.

Purpose of the Study:

• To estimate resistance exercise energy expenditure using triaxial accelerometry.
• To identify the most effective body location for wearing triaxial accelerometers during resistance exercise.

Main Methods:

• Thirty participants (15 male, 15 female) completed a resistance exercise protocol with 10-repetition maximum (10RM) loads.
• Triaxial accelerometers were worn on the wrist, waist, and ankle, alongside heart rate monitors and portable metabolic systems.
• Net energy expenditure was measured and correlated with accelerometer data from various locations.

Main Results:

• Net energy expenditure showed significant correlations with vertical, horizontal, and sum of 3-axis counts at the waist.
• Horizontal accelerometer counts at the wrist also correlated with energy expenditure.
• A regression equation incorporating waist accelerometer data, fat-free mass, and sex explained 73% of the variance in energy expenditure.

Conclusions:

• Triaxial accelerometers worn at the waist can estimate resistance exercise energy expenditure.
• Waist-worn triaxial accelerometers do not appear to offer significant advantages over uniaxial accelerometers for this application.
• Accelerometer technology shows potential for individuals and athletes focused on precise energy balance during resistance training.