How is protein beneficial to endurance athletes?
Dietary protein is the key nutrient that helps the body grow and repair by stimulating muscle protein synthesis. Muscle is damaged as a result of strenuous exercise, therefore consuming sufficient protein helps athletes to recover from training, and allows them to train harder and more often in order to maximise performances.
What other benefits does protein bring?
The role of protein for growing and developing new tissue goes beyond muscle alone. Protein makes up every cell in the body and is essential for the structure, function and regulation of all organs and tissues. Protein has a half-life of just a few hours, therefore adequate protein is vital, not only to generate new proteins for normal bodily functions, but also to support the additional stress, energy demands and adaptive response placed on the body during vigorous training regimes.
There is a lot of stress placed on an endurance athlete’s body during training, especially runners who experience repeated high impact stress. This increases the risk of injury for muscle, bone and connective tissue if the diet is lacking in protein.
Protein also plays a role in immune function to keep the body healthy which is important for athletes and for endurance athletes who are susceptible to upper respiratory tract infections.
How can protein aid with weight management?
Increasing protein intake during periods of energy restriction is a common strategy to promote fat loss. This is achieved by an increased thermogenic response to a high protein diet compared to a low protein diet. Together with this slight increase in energy expenditure from digesting food, there is also a wealthy of literature to support improved feelings of satiety following a meal high in protein, leading to subsequent reductions in energy intake. This is particularly effective at breakfast; a meal that is often lacking in protein and when corrected is associated with superior food choices later in the day.
Furthermore, higher protein intakes are important for athletes during energy restriction to avoid significant losses in lean muscle mass.
What are the chief sources of protein for athletes and how do they differ?
There are 3 main types of dietary protein; whey (meat, fish, eggs), casein (dairy) and plant based such as soy, all of which are considered ‘complete’ proteins as they contain all essential amino acids. These amino acids cannot be made by the body and therefore must be sourced through the diet.
Whey proteins are recommended ahead of other types of protein to maximise the muscle protein synthetic response to exercise because they are rapidly absorbed and are rich in leucine, a key amino acid required to trigger muscle protein synthesis.
Casein is a slow-release protein and has a lower concentration of leucine compared to whey, as does soy, and it’s likely because of this that whey is superior for stimulating protein synthesis.
Athletes should consume a source of high quality protein every 3-4 hours, but also having some before bed can promote recovery during sleep. Therefore it may be advantageous to consume casein protein before bed to drip-feed your muscles throughout the night.