Patterns of energy availability of free-living athletes display day-to-day variability that is not reflected in laboratory-based protocols: Insights from elite male road cyclists

The physiological effects of low energy availability (EA) have been studied using a homogenous daily EA pattern in laboratory settings. However, whether this daily EA pattern represents those of free-living athletes and is therefore ecologically valid is unknown. To investigate this, we assessed daily exercise energy expenditure, energy intake and EA in 10 free-living elite male road cyclists (20 min Mean Maximal Power: 5.27 ± 0.25 W · kg^-1) during 7 consecutive days of late pre-season training. Energy intake was measured using the remote-food photography method and exercise energy expenditure estimated from cycling crank-based power-metres. Seven-day mean ± SD energy intake and exercise energy expenditure was 57.9 ± 10.4 and 38.4 ± 8.6 kcal · kg FFM^-1 · day^-1, respectively. EA was 19.5 ± 9.1 kcal · kg FFM^-1 · day^-1. Within-participants correlation between daily energy intake and exercise energy expenditure was .62 (95% CI: .43 - .75; P < .001), and .60 (95% CI: .41 - .74; P < .001) between carbohydrate intake and exercise energy expenditure. However, energy intake only partially compensated for exercise energy expenditure, increasing 210 kcal · day^-1 per 1000 kcal · day^-1 increase in expenditure. EA patterns displayed marked day-to-day fluctuation (range: -22 to 76 kcal · kg FFM^-1 · day^-1). The validity of research using homogenous low EA patterns therefore requires further investigation.
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Bibliographic Details
Subjects:
Notations:endurance sports biological and medical sciences
Tagging:Low Energy Availability RED-S
Published in:Journal of Sports Sciences
Language:English
Published: 2022
Online Access:https://doi.org/10.1080/02640414.2022.2115676
Volume:40
Issue:16
Pages:1849-1856
Document types:article
Level:advanced