Low Energy Availability Followed by Optimal Energy Availability Does Not Benefit Performance in Trained Females

Mikkel Oxfeldt*, Daniel Marsi, Peter M. Christensen, Ole Emil Andersen, Frank Ted Johansen, Maj Bangshaab, Jeyanthini Risikesan, Jan S. Jeppesen, Ylva Hellsten, Stuart M. Phillips, Anna K. Melin, Niels Ørtenblad, Mette Hansen

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

1 Citationer (Scopus)

Abstract

Purpose Short periods of reduced energy availability are commonly undertaken by athletes to decrease body mass, possibly improve the power-to-mass ratio, and enhance physical performance. Our primary aim was to investigate the impact of 10 d of low energy availability (LEA) followed by 2 d of optimal energy availability (OEA) on physical performance parameters in trained females. Second, physiological markers at the whole-body and molecular level related to performance were evaluated. Methods Thirty young trained eumenorrheic females were matched in pairs based on training history and randomized to a 10-d intervention period of LEA (25 kcal·fat-free mass (FFM)-1·d-1) or OEA (50 kcal·FFM-1·d-1) along with supervised exercise training. Before the intervention, participants underwent a 5-d run-in period with OEA + supervised exercise training. After the LEA intervention, 2 d of recovery with OEA was completed. Participants underwent muscle biopsies, blood sampling, physical performance tests, body composition measurements, and resting metabolic rate measurements. A linear mixed model was used with group and time as fixed effects and subject as random effects. Results Compared with OEA, LEA resulted in reduced body mass, muscle glycogen content, repeated sprint ability, 4-min time-trial performance, and rate of force development of the knee extensors (absolute values; P < 0.05). Two days of recovery restored 4-min time-trial performance and partly restored repeated sprint ability, but performance remained inferior to the OEA group. When the performance data were expressed relative to body mass, LEA did not enhance performance. Conclusions Ten days of LEA resulted in impaired performance (absolute values), with concomitant reductions in muscle glycogen. Two days of recovery with OEA partially restored these impairments, although physical performance (absolute values) was still inferior to being in OEA. Our findings do not support the thesis that LEA giving rise to small reductions in body mass improves the power-to-mass ratio and thus increases physical performance.

OriginalsprogEngelsk
TidsskriftMedicine and Science in Sports and Exercise
Vol/bind56
Udgave nummer5
Sider (fra-til)902-916
ISSN0195-9131
DOI
StatusUdgivet - 2024

Bibliografisk note

Funding Information:
S. M. P. reports grants or research contracts from the US National Dairy Council, Canadian Institutes for Health Research, Dairy Farmers of Canada, Roquette Freres, Ontario Centre of Innovation, Nestle Health Sciences, Myos, National Science and Engineering Research Council, Friesland Campina, and the US National Institutes of Health during the conduct of the study; personal fees from Nestle Health Sciences, nonfinancial support from Enhanced Recovery, outside the submitted work. S. M. P. has patents licensed to Exerkine but reports no financial gains from patents or related work.

Publisher Copyright:
© 2024 Lippincott Williams & Wilkins.

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