Energy expenditure estimation during walking in overweight and obese adults from the ActiTrainer accelerometer and heart rate

Background: Gold standard methods of measuring energy expenditure (EE) are impractical and expensive (Brouchard et al., 1983: Am J Clin Nutr, 14, 255–260). Conversely, several studies have shown that accelerometers can provide good estimates of EE in healthy (Fudge et al., 2007: Med Sci Sports Exerc, 39, 192–198) and overweight individuals (Jacobi et al., 2006: Obesity, 15(4), 950–956) during structured exercise in the laboratory. Furthermore, the accuracy of EE prediction can be enhanced using a combination of heart rate (HR) and accelerometer counts (AC) (Fudge et al., 2007). However, studies have shown that AC vary between different models of accelerometer (Welk et al., 2004: Med Sci Sports Exerc, 36, 1637–1645) and the validity of the uni-axial ActiTrainer accelerometer to predict EE in overweight and obese adults has not yet been explored.