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Increasing the meal frequency does not promote exercise‐induced muscle hypertrophy in rats
Author(s) -
Tanaka Chihiro,
Fujii Takako,
Nakashima Ayumi,
Xu Minjun,
Sonou Tomohiro,
Okamura Koji
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.631.12
Subject(s) - muscle hypertrophy , meal , medicine , endocrinology , muscle protein , urea , excretion , skeletal muscle , protein catabolism , catabolism , amino acid , chemistry , biology , metabolism , biochemistry
Skeletal muscle protein synthesis has been reported to be maximized after ingesting 20 g of protein, and protein consumption of 2.0 g/kg BW/day is the upper limit to promote exercise‐induced muscle synthesis in humans. Therefore, 100 g of protein maximizes the muscle synthesis in a 50 kg human, and consuming 20 g of protein 5 times a day may promote muscle hypertrophy. To examine the effect of meal frequency on exercise‐induced muscle hypertrophy, male rats performed climbing exercise (19:00 – 20:00) three times a week were divided into a group fed 2 meals (08:00 – 09:00 and 20:00 – 21:00; 2M) or a group fed 5 meals (every three hours between 08:00–21:00; 5M). The amount of protein given to both groups was equal. The rats were killed pre‐and post‐exercise on the last day of the 8‐week study. The flexor hallucis longus muscle weight tended to be higher in 2M than 5M, while the weights of other muscles did not differ. The plasma urea level was significantly higher in 5M than 2M. The urinary urea nitrogen excretion did not differ significantly but it was higher in 5M than 2M by 19%. The pre‐exercise plasma branched‐chain amino acid level tended to be higher in 5M than 2M, while it was similar post‐exercise. The plasma levels of other amino acids did not differ between the groups pre‐or post‐exercise. Therefore, increasing the meal frequency may increase amino acid catabolism, and does not promote exercise‐induced muscle hypertrophy.