Whey protein can build lean muscle and prevent protein breakdown.81 Studies suggest whey protein isolate as a useful supplement for muscle recovery and immune regulation for athletes and others.In addition, protein supplementation may help enhance muscle protein anabolism and provide a means of reducing the progressive loss of muscle mass with age. It has also been shown to enhance the production of glutathione, the body’s natural antioxidant.

Long used by athletes to improve strength and exercise performance, creatine is being recognized as more than a muscle-building supplement. Creatine is present in the body. Skeletal muscles, the heart, brain, and other tissues metabolize creatine and use it as a major energy storage form. Creatine boosts levels of ATP in the mitochondria, the cells’ energy powerhouses.

While studies have shown that creatine may indeed help build muscle and strength in explosive short duration activities, other research has demonstrated the supplement’s role in enhancing healthy muscle mass in aging humans.

Glutamine is a non-essential amino acid that generates energy and helps increase strength, quicker recovery, and exercise endurance.Blood ammonia concentration increases during endurance exercise and has been proposed as a cause for both peripheral and central fatigue. In trials, glutamine supplementation reduced the accumulation of blood ammonia during prolonged, strenuous exercise in high-level athletes. As an immune booster, glutamine supplementation may prevent the negative effects of strenuous exercise on immune function. Moreover, glutamine supplementation has a protective effect in the DNA fragmentation, mitochondrial membrane depolarization and apoptosis, and in regulation of the inflammatory process and immune suppression, which are induced by a single session of exercise. Glutamine also plays an important role in maintaining functional integrity of the gut. As a gut-trophic factor, glutamine improves intestinal function, allowing better absorption of nutrients.