Key benefits of Protein
1) Growth and repair of lean muscle tissue
2) Improves body composition
3) Enhances gastrointestinal health
4) Can improve immune health
Protein has a number of important roles in the body including the manufacturing of hormones, enzymes, messengers and immune-system components, as well as playing the main structural process of every muscle fibre. The amino acids that make up various proteins are therefore critical for the structure and regulation of cells and without adequate protein from our diet the body simply will not function. Protein can also help to reduce body fat levels due to the enhanced feeling of satiety and increase in fat utilisation that typically occurs. The effects on gastrointestinal health are also highly documented with increased glutamine intake being shown to develop overall gut function as well as aid decline in the immune system. The amino acid cysteine (typically found in high amounts in whey) will also help to promote glutathione level in turn having a positive effect on the immune system.
The most appreciated benefit of protein is perhaps the effects on muscle fibre remodelling and structure. The processes of muscle protein synthesis and muscle protein breakdown occur concurrently, with both exercise and dietary protein consumption (rich in BCAAs) having a direct effect on the rate of these. This balance between the process of muscle protein synthesis and muscle protein breakdown will determine the net gain, loss, or balance of myofibrillar proteins and whether muscle fibre size increases (hypertrophy) or decreases (atrophy).
Muscle protein synthesis is stimulated through all types of exercise modes but with this also augments muscle degradation – the rate of this depending on exercise type. Figure 1 represents the effects of a dietary protein intake on muscle protein synthesis and breakdown. It illustrates the importance of how dietary protein consumption through supplements such as whey can help to stimulate muscle protein synthesis and reduce muscle breakdown. This constant protein turnover allows for a muscle fibre to change by removing damaged proteins and replacing them with new proteins which alters a muscle fibre structure eventually leading to training adaptation.