The Impact of Nutrition and Exercise on Muscle Growth
Muscle tissue, on average, makes up the majority of our body weight, and it contains the majority of all body proteins. On a daily basis, muscle tissue breaks down and it also regenerates. There are many factors that can accelerate the rate at which muscle will breakdown, just as there are factors that support the regeneration and growth of our muscle tissue.
The rate of muscle atrophy (wasting) will increase with inactivity, lack of movement and lack of resistance of our muscles. Muscle breakdown accelerates with age. As we age, the nerves and fibers that move muscles start to shrink down and cannot function as optimally. Also, the aging process begins the decline of our hormones that help support Muscle Protein Synthesis (MPS).
The Lifestyle factors that support MPS are to always stay active and exercise, and to support the muscle recovery with adequate amounts of protein and amino acids to rebuild, regenerate, and grow muscle tissue. Our menu plan choices should focus on less inflammatory signals. Foods like added sugars, alcohol, and overly processed choices will increase systemic inflammation and support muscle protein breakdown (MPB).
ROLE OF PROTEIN AND TRAINING
Protein ingestion and resistance exercise both stimulate the process of new MPS. Our health goal is to continue to have a healthy balance of MPS exceeding over MPB. As we age, the Standard American Diet tends to consume more carbohydrates and less proteins and can lead to a condition called Sarcopenia, which is age-related muscle wasting.
As mentioned earlier, muscle tissue contains protein, and therefor muscle tissue is made from protein and amino acids. When we look at the studies to prevent MPB, adequate protein intake (at least 1-1.2 g/kg body weight) is recommended, however, in some cases, even more protein has been shown to be beneficial for physically active athletes and exercisers.
BCAA AND THE MTOR PATHWAY
Protein, and in particular, Branch Chain Amino Acids (BCAA) that are in protein, are essential to for MPS. The BCAAs comprise of leucine, isoleucine, and valine, which are essential amino acids. BCAAs, with a special focus on Leucine, has been shown to increase MPS and the production of lean body mass, as well as stimulate a pathway called MTOR (MTORc1). MTOR expression leads to protein synthesis, activates the Krebs Cycle and ATP production providing energy to our cells. More energy to our cells is more energy we have to perform and function better. The MTOR pathway also slows down the breakdown of muscle tissue (muscle atrophy).
In conclusion, adequate protein, staying physically active, and living a healthy lifestyle are the key factors to support more muscle tissue and have healthy function and healthy aging. If eating enough protein throughout the day is a challenge, an easy way to ensure you are getting in enough protein and our Essential Amino Acids like BCAA, is to use supplementation.