The growth of new muscle tissue and its maintenance happens during a specific metabolic process known as muscle protein synthesis. The body constantly seeks new sources of energy, and one of the ways it can satisfy these energy requirements is by using the protein found in your muscles. This means, that if you want to keep your muscles the way they are or make them bigger, the rate at which muscle protein synthesis occurs must be greater than the rate at which protein breaks down. Eating adequate amounts of protein and doing some kind of strength training is crucial to increase muscle protein synthesis.
Muscle loss caused by aging
The quantity and quality of the muscle tissue you have in your body is in a state of constant degradation. With age, this breakdown of muscle tissue becomes faster. The American College of Sports medicine has stated that muscular atrophy related to aging varies a lot individually, and can increase or decrease based on changes happening in the endocrine system as well as the quality of the diet. Even though the rate of muscle breakdown might be different for every individual, numerous studies have shown that leading a sedentary lifestyle past the age of 25 leads to a loss in muscle tissue of about 3-5% every 10 years.
The effects of lifting weights
In order to stop the effects of muscle breakdown, people take up a strength training program. When the muscles are put under mechanical stress caused by heavy weights, muscle fibers experience micro-trauma and damage. This damage to the fibers causes the satellite cells inside them to activate. Activating these cells causes various metabolic processes such as cell division and adaptation which eventually lead to increased muscle growth provided the newly grown cells have adequate nutrition.
Meeting your protein needs
Lifting weights triggers the metabolic processes needed for muscle growth, but if they are not supported by supplying the muscles with the adequate amount of nutrients needed to repair the damage done during weightlifting, they will remain the same or they will start to break down. The general recommendation for adults is that they consume at least 0.8 grams of protein per kilo of body weight daily. For athletes that endure intense physical activity this amount can go up to 2.5g per kg. This protein should ideally come from low-fat foods which have all 9 essential amino acids in them, like poultry, lean meat, milk, and eggs.
Consuming protein regularly will bring the muscles constant supply of amino acids so that protein synthesis can occur, which will prevent muscle loss. If you want your muscles to grow, you will have to eat a lot more protein than the recommended daily amount. Consult with a registered nutritionist/dietician to help you decide how much protein you need for optimal muscle growth or muscle maintenance.
Timing your protein intake
It has been repeatedly shown by numerous studies that you optimize your muscle growth by ingesting protein before, during and after the workout. Studies examining the effects of protein timing have found that supplementing with protein before you train can increase the rate at which essential nutrients needed for optimal muscle growth are transported to the muscles by more than two and half times the normal rate after working out.