Protein supplements areprimarily ingested to promote muscle strength, function, and possibly size. Currently, it is not possible to form a consensus position regarding the benefit of protein or amino acid supplements in exercise training. Determination of whether supplements are beneficial has been hampered by the failure to select appropriate endpoints for evaluation of a positive effect. Furthermore, studies focused at a more basic level have failed to agree on the response of protein metabolism to exercise. An additional complication of dietary studies that is not often taken into account is the amount of energy intake. Because of these and other complications, studies at the whole body level have not yielded a clear picture of the need for, or response to, dietary protein or amino acid supplements.
The potential benefit of protein supplementation has to be tailored to the goal of supplementation. For example, an endurance athlete may want a supplement that will speed recovery from workouts without adding muscle mass, whereas a weight-lifter will seek a supplement specifically to increase muscle mass and power. Factors yet to be determined are the optimal composition of a supplement (e.g. type of protein, composition of amino acid mixture, nature of non-protein energy), the optimal timing of ingestion in relation to exercise, and the amount of protein or amino acids per serving. Only when an optimal supplement is evaluated under controlled conditions (comparable levels of exercise intensity, training duration, and other nutritional intake) can the question of protein requirements during exercise be definitively answered.
Though there appears to be no evidence that any particular protein supplement positively improves performance, this cannot be considered as proof that there is no supplement that might be useful. It can be speculated that a protein supplement should be useful to stimulate net muscle protein synthesis, particularly if the supplement has the optimal proportion of individual amino acids. However, experiments have yet to be performed that document such a beneficial effect of protein supplements.
Creatinine levels will increase with increased protein intake. Till there is definite evidence of any advantage in taking protein supplements, it is best to avoid it. Please do not take unnecessary vitamin A as it is toxic in high amounts.