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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| Subjects: | |
|---|---|
| Notations: | endurance sports biological and medical sciences |
| Tagging: | Low Energy Availability RED-S |
| Published in: | Journal of Sports Sciences |
| Language: | English |
| Published: |
2022
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| Online Access: | https://doi.org/10.1080/02640414.2022.2115676 |
| Volume: | 40 |
| Issue: | 16 |
| Pages: | 1849-1856 |
| Document types: | article |
| Level: | advanced |