Article révisé par les pairs
Résumé : Muscle mass is the major deposit of protein molecules with dynamic turnover between net protein synthesis and 8 degradation. In human subjects, invasive and non-invasive techniques have been applied to determine their 9 skeletal muscle catabolism of amino acids at rest, during and after different forms of physical exercise and training. 10 The aim of this review is to analyse the turnover flux and the relative oxidation rate of different types of muscle 11 proteins after one bout of exercise as well as after resistance and endurance condition of training. Protein feeding 12 in athletes appears to be a crucial nutrition necessity to promote the maintenance of muscle mass and its 13 adaptation to the need imposed by the imposed technical requirements. In resting human individuals, the 14 recommended protein daily allowance is about 0.8 g (dry weight)kg−1 body weight per 24 h knowing that 15 humans are unable to accumulate protein stores in muscle tissues. Nevertheless, practical feeding recommendations 16 related to regular exercise practice are proposed to athletes by different bodies in order to foster their skills and 17 performance. This review will examine the results obtained under endurance and resistance type of exercise while 18 consuming single or repeated doses of various ingestions of protein products (full meat, essential amino acids, 19 specific amino acids and derivatives, vegetarian food). From the scientific literature, it appears that healthy athletes 20 (and heavy workers) should have a common diet of 1.25 g kg−1 24 h to compensate the exercise training muscle 21 protein degradation and their resynthesis within the following hours. A nitrogen-balance assay would be 22 recommended to avoid any excessive intake of protein. Eventually, a daily equilibrated food intake would be 23 of primer importance versus inadequate absorption of some specific by-products.