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Soy protein ingestion results in less prolonged p70S6 kinase phosphorylation compared to whey protein after resistance exercise in older men

Authors :
Paul A. Della Gatta
David Cameron-Smith
Cameron J. Mitchell
James F. Markworth
Aaron C. Petersen
Source :
Journal of the International Society of Sports Nutrition
Publication Year :
2015
Publisher :
Informa UK Limited, 2015.

Abstract

Background The phosphorylation of p70S6 Kinase (p70S6K) is an important step in the initiation of protein translation. p70S6K phosphorylation is enhanced with graded intakes of whey protein after resistance exercise. Soy protein ingestion results in lower muscle protein synthesis after exercise compared with whey; however, the underlying mechanisms responsible for this difference have not been reported. Findings 13 older men (60–75) completed an acute bout of lower body resistance exercise and ingested 30 g of soy protein or carbohydrate. Muscle biopsies were obtained in the rested and fasted state and 2 and 4 hours post exercise. Phosphorylation status of p70S6K was measured with western blot. Results were compared with previously reported data from the ingestion of 30 g of whey protein or placebo. p70S6K phosphorylation was increased 2, but not 4 hours post exercise with soy protein ingestion. p70S6K phosphorylation was not increased post exercise with carbohydrate ingestion. Conclusions Ingesting 30 g of either whey or soy protein resulted in equivalent p70S6K phosphorylation at 2 hours post exercise, however, unlike whey, soy protein failed to promote prolonged phosphorylation of p70S6K to 4 hours post-exercise.

Details

ISSN :
15502783
Volume :
12
Database :
OpenAIRE
Journal :
Journal of the International Society of Sports Nutrition
Accession number :
edsair.doi.dedup.....4a34be2fb73122315da5faa63f71dd20
Full Text :
https://doi.org/10.1186/s12970-015-0070-2