Validity of energy expenditure estimation methods during 10 days of military training

Abstract

Wearable physical activity (PA) monitors have improved the ability to estimate free-living total energy expenditure (TEE) but their application during arduous military training alongside more well-established research methods has not been widely documented.This study aimed to assess the validity of two wrist-worn activity monitors and a PA log against doubly labeled water (DLW) during British Army Officer Cadet (OC) training. For 10 days of training, twenty (10 male and 10 female) OCs (mean ± SD: age 23 ± 2 years, height 1.74 ± 0.09 m, body mass 77.0 ± 9.3 kg) wore one researchgrade accelerometer (GENEActiv, Cambridge, UK) on the dominant wrist, wore one commercially available monitor (Fitbit SURGE, USA) on the non-dominant wrist, and completed a self-report PA log. Immediately prior to this 10-day period, participants consumed a bolus of DLW and provided daily urine samples, which were analyzed by mass spectrometry to determine TEE. Bivariate correlations and limits of agreement (LoA) were employed to compare TEE from each estimation method to DLW. Average daily TEE from DLW was 4112 ± 652 kcal·day −1 against which the GENEActiv showed near identical average TEE (mean bias ± LoA: −15 ± 851 kcal . day −1 ) while Fitbit tended to underestimate (−656 ± 683 kcal·day −1 ) and the PA log substantially overestimate (+1946 ± 1637 kcal·day −1 ). Wearable physical activity monitors provide a cheaper and more practical method for estimating free-living TEE than DLW in military settings. The GENEActiv accelerometer demonstrated good validity for assessing daily TEE and would appear suitable for use in large-scale, longitudinal military studies. K E Y W O R D Saccelerometry, army, doubly labeled water, physical activity, wearable technology

Recommendations for Determining the Validity of Consumer Wearables and Smartphones for the Estimation of Energy Expenditure: Expert Statement and Checklist of the INTERLIVE Network

“…Therefore, based on the current available evidence, we recommend that the criterion measure for the validation of specific activities or exercise protocols be indirect calorimetry, with DLW used for free-living studies. All five studies in the systematic literature review validating consumer wearables in a free-living context utilised the DLW method [10,[36][37][38][39], while 3 (10%) of the 28 semi-free-living protocols utilised a metabolic chamber [10,37,40]. The remaining studies with a semi-free-living protocol ( 25) and all 52 laboratory protocols selected indirect calorimetry in the form of a portable system or metabolic cart.…”

Measuring the Exercise Component of Energy Availability during Arduous Training in Women

“…The context of basic military training is germane for developing EA measurement, since it is characterized with high physical demands and multiple stressors, in free-living but well circumscribed field environment. It is repeatable (12) and provides routine measures of training adaptation (1). Furthermore, since a ban on women joining the infantry has recently been lifted, women may be required to train more arduously which could put them at increased risk of conditions associated with low EA, like premature osteoporosis, increased cardiovascular risk or reproductive dysfunction (1,13,14).…”

Wearable Health Devices in Health Care: Narrative Systematic Review (Preprint)

“…Because false alarms would reduce user alertness and prevent user adherence from the feedback provided, efficient mechanisms are needed to detect and diagnose deviations occurring in captured data [126]. (5) Other issues such as cost, low data collection and processing efficiency, unstable human-computer interaction interfaces, and incomplete construction of big data health clouds need to be further improved [9,13,122].…”

“…Since then, wearable technology has received considerable attention from researchers all around the world. In recent years, with the development of the internet, intelligent hardware, and big data, wearable technology has developed rapidly in various fields such as health care [2], education and culture [3], social networking [4], and the military [5]. Some of these technologies are becoming part of people's daily life in the form of accessories such as smart watches, smart bracelets, armbands, and glasses [6].…”