Alterations in protein metabolism during space flight and inactivity

Arny A. Ferrando, Doug Paddon-Jones, Robert R. Wolfe

    Research output: Contribution to journalArticlepeer-review

    47 Scopus citations


    Space flight and the accompanying diminished muscular activity lead to a loss of body nitrogen and muscle function. These losses may affect crew capabilities and health in long-duration missions. Space flight alters protein metabolism such that the body is unable to maintain protein synthetic rates. A concomitant hypocaloric intake and altered anabolic/catabolic hormonal profiles may contribute to or exacerbate this problem. The inactivity associated with bedrest also reduces muscle and whole-body protein synthesis. For this reason, bedrest provides a good model for the investigation of potential exercise and nutritional countermeasures to restore muscle protein synthesis. We have demonstrated that minimal resistance exercise preserves muscle protein synthesis throughout bedrest. In addition, ongoing work indicates that an essential amino acid and carbohydrate supplement may ameliorate the loss of lean body mass and muscle strength associated with 28 d of bedrest. The investigation of inactivity-induced alterations in protein metabolism, during space flight or prolonged bedrest, is applicable to clinical populations and, in a more general sense, to the problems associated with the decreased activity that occur with aging.

    Original languageEnglish (US)
    Pages (from-to)837-841
    Number of pages5
    Issue number10
    StatePublished - Oct 2002


    • Amino acid supplementation
    • Anabolic/catabolic hormones
    • Bed rest
    • Muscle protein metabolism
    • Resistance exercise

    ASJC Scopus subject areas

    • Endocrinology, Diabetes and Metabolism
    • Nutrition and Dietetics


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