Isolated & Combined Wearable Technology Underestimate the Total Energy Expenditure of Professional Young Rugby League Players; A Doubly Labelled Water Validation Study

<p>Costello, N, Deighton, K, Cummins, C, Whitehead, S, Preston, T, and Jones, B. Isolated & combined wearable technology underestimate the total energy expenditure of professional young rugby league players; a doubly labelled water validation study. J Strength Cond Res XX(X): 000–000, 2019—Accurately determining total energy expenditure (TEE) enables the precise manipulation of energy balance within professional collision-based sports. Therefore, this study investigated the ability of isolated or combined wearable technology to determine the TEE of professional young rugby league players across a typical preseason and in-season period. Total energy expenditure was measured via doubly labelled water, the criterion method, across a fourteen-day preseason (<i>n</i> = 6) and 7-day in-season (<i>n</i> = 7) period. Practical measures of TEE included SenseWear Pro3 Armbands in isolation and combined with metabolic power derived from microtechnology units. SenseWear Pro3 Armbands significantly under-reported preseason (5.00 [2.52] MJ·d⁻¹; <i>p</i> = 0.002) and in-season (2.86 [1.15] MJ·d⁻¹; <i>p</i> < 0.001) TEE, demonstrating a <i>large</i> and <i>extremely large</i> standardized mean bias, and a <i>very large</i> and <i>large</i> typical error, respectively. Combining metabolic power with SenseWear Pro3 Armbands <i>almost certainly</i> improved preseason (0.95 [0.15] MJ·d⁻¹; Effect size = 0.32 ± 0.04; <i>p</i> < 0.001) and in-season (1.01 [0.15] MJ·d⁻¹; ES = 0.88 ± 1.05; <i>p</i> < 0.001) assessment. However, SenseWear Pro3 Armbands combined with metabolic power continued to significantly under-report preseason (4.04 [2.38] MJ·d⁻¹; <i>p</i> = 0.004) and in-season (2.18 [0.96] MJ·d⁻¹; <i>p</i> = 0.002) expenditure, demonstrating a <i>large</i> and <i>very large</i> standardized mean bias, and a <i>very large</i> and <i>large</i> typical error, respectively. These findings demonstrate the limitations of utilizing isolated or combined wearable technology to accurately determine the TEE of professional collision-based sport athletes across different stages of the season.