Protein supplementation advantages: concentrated amounts of high quality protein, easily consumed, practical, readily available, provides raw material for both muscle construction and repair, promotes glycogen resynthesis, plays an important role in the immune system, is critical to the endocrine (hormone production) system, facilitates the transmission of nerve impulses throughout the nervous system, prevents sport anaemia by promoting increased synthesis of haemoglobin, myoglobin and oxidative enzymes
Protein supplementation disadvantages: can get enough protein from a properly constituted well-balanced diet, strain on kidneys - increased processing and filtration (excess not stores), costly.