Maximal sustainable energy intake during transatlantic ocean rowing is insufficient for total energy expenditure and skeletal muscle mass maintenance

• Published in: Experimental physiology 2024-02, Vol.109 (2), p.227-239
• Main Authors: Holsgrove‐West, Rosalind K., Revuelta Iniesta, Raquel, Abdelrahman, Doaa R., Murton, Andrew J., Wall, Benjamin T., Stephens, Francis B.
• Format: Article
• Language: English
• Subjects: Adult; Age; Aged; atrophy; Basal Metabolism - physiology; Body Composition - physiology; Body mass; doubly labelled water; Energy; Energy expenditure; energy expenditure endurance; Energy intake; Energy Intake - physiology; Energy Metabolism - physiology; Female; Females; Gender differences; Humans; Male; Males; Metabolic rate; Metabolism; Middle Aged; muscle maintenance; Muscle, Skeletal; ocean rowing; Oceans and Seas; Rowing; Sex differences; Skeletal muscle; Whisky; Young Adult
• ISSN: 0958-0670; 1469-445X
• DOI: 10.1113/EP091319

Studies of extreme endurance have suggested that there is an alimentary limit to energy intake (EI) of ∼2.5 × resting metabolic rate (RMR). To gain further insight, this study aimed to simultaneously measure EI, total energy expenditure (TEE) body mass and muscle mass in a large cohort of males and females of varying ages during a transatlantic rowing race. Forty‐nine competitors (m = 32, f = 17; age 24–67 years; time at sea 46 ± 7 days) in the 2020 and 2021 Talisker Whisky Atlantic Challenge rowed 12–18 hday−1 for ∼3000 miles. TEE was assessed in the final week of the row using 2H218O doubly labelled water, and EI was analysed from daily ration packs over this period. Thickness of relatively active (vastus lateralis, intermedius, biceps brachaii and rectus abdominus) and inactive (gastrocnemius, soleus and triceps) muscles was measured pre (