Kerr, AD and Slater, GJ and Byrne, NM, Influence of subject presentation on interpretation of body composition change after 6 months of self-selected training and diet in athletic males, European Journal of Applied Physiology, 118, (6) pp. 1273-1286. ISSN 1439-6319 (2018) [Refereed Article]
Copyright 2018 Springer-Verlag GmbH Germany, part of Springer Nature
Purpose: High precision body composition assessment methods accurately monitor physique traits in athletes. The acute impact of subject presentation (ad libitum food and fluid intake plus physical activity) on body composition estimation using field and laboratory methods has been quantified, but the impact on interpretation of longitudinal change is unknown. This study evaluated the impact of athlete presentation (standardised versus non-standardised) on interpretation of change in physique traits over time. Thirty athletic males (31.2±7.5 years; 182.2±6.5 cm; 91.7±10.3 kg; 27.6±2.6 kg/m2 ) underwent two testing sessions on 1 day including surface anthropometry, dual-energy X-ray absorptiometry (DXA), bioelectrical impedance spectroscopy (BIS) and air displacement plethysmography (via the BOD POD), with combinations of these used to establish three-compartment (3C) and four-compartment (4C) models.
Methods: Tests were conducted after an overnight fast (BASEam) and ~7 h later after ad libitum food/fluid and physical activity (BASEpm). This procedure was repeated 6 months later (POSTam and POSTpm). Magnitude of changes in the mean was assessed by standardisation.
Results: After 6 months of self-selected training and diet, standardised presentation testing (BASEam to POSTam) identified trivial changes from the smallest worthwhile effect (SWE) in fat-free mass (FFM) and fat mass (FM) for all methods except for BIS (FM) where there was a large change (7.2%) from the SWE. Non-standardised follow-up testing (BASEam to POSTpm) showed trivial changes from the SWE except for small changes in FFM (BOD POD) of 1.1%, and in FM (3C and 4C models) of 6.4 and 3.5%. Large changes from the SWE were found in FFM (BIS, 3C and 4C models) of 2.2, 1.8 and 1.8% and in FM (BIS) of 6.4%. Non-standardised presentation testing (BASEpm to POSTpm) identified trivial changes from the SWE in FFM except for BIS which was small (1.1%). A moderate change from the SWE was found for BOD POD (3.3%) and large for BIS (9.4%) in FM estimations.
Conclusions: Changes in body composition utilising non-standardised presentation were more substantial and often in the opposite direction to those identified using standardised presentation, causing misinterpretation of change in physique traits. Standardised presentation prior to body composition assessment for athletic populations should be advocated to enhance interpretation of true change.
|Item Type:||Refereed Article|
|Keywords:||Body composition · Air-displacement plethysmography · Dual-energy X-ray absorptiometry · Bioelectrical impedance spectroscopy · Surface anthropometry|
|Research Division:||Health Sciences|
|Research Group:||Sports science and exercise|
|Research Field:||Exercise physiology|
|Objective Group:||Specific population health (excl. Indigenous health)|
|Objective Field:||Men's health|
|UTAS Author:||Byrne, NM (Professor Nuala Byrne)|
|Web of Science® Times Cited:||3|
|Deposited By:||Health Sciences|
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