Physical performance and training response during Ramadan observance, with particular reference to protein metabolism.

This review examines information on the effects of Ramadan observance upon the metabolism, training and performance of athletes, with particular reference to proteins and amino acids. Increased gluconeogenesis and/or a reduced intake of protein could lead to a decrease of lean tissue, with adverse effects on muscular performance, and the lack of immediate protein ingestion could compromise responses to strength training. Actual responses vary quite widely, depending on culture and the individual's level and type of athletic involvement. In elite competitors, there is typically an increased fractional ingestion of protein with a small reduction in overall energy intake, and this may lead to small reductions of body and lean tissue mass. There are often small decreases of performance, particularly in activities requiring vigorous and/or repetitive muscular contraction. More information is needed on responses in situations where protein intake is likely to be inadequate (adolescent growth, those maintaining vegetarian diets or from poor countries and disciplines with very high overall energy needs) and when vigorous muscle training is in progress. However, in most of the situations studied to date, Ramadan observance has had only limited adverse consequences for either training or competitive performance.