Muscle tissues are made up of a repeated structure of protein filaments: myosin and actin, which interact with each other to initiate muscle contractions. Over time, the mechanical stress from continuous movement leads to damage in the protein filaments. As a result, your muscles require a daily supply of protein to rebuild themselves and maintain function. The mechanical stress from weight training is intense enough to make your muscles larger and stronger, which is why bodybuilders tend to train with very heavy weights. They might use supplements like the best protein powders and protein bars - it's how they ensure their bodies have enough building blocks to maintain their sculpted physique. However, it may take more than just drinking protein shakes to achieve the desired muscle. Many different factors affect the strength and size of your muscle fibers, including the type and amount of protein you consume.
#### How Does Protein Build Muscle?
The ongoing process of muscle fibers being built and damaged is called muscle protein turnover. If your body is in what is called an anabolic state, it will build more muscle than it breaks down. If you are in a catabolic state, you will lose muscle mass. Muscle protein turnover is a relatively slow metabolic process and takes time before results become noticeable. As such, the goal of building muscle is to maintain a continuous anabolic state long enough to produce the desired effect. According to Frontiers in Nutrition, two conditions must be met for your body to enter an anabolic state: your muscle fibers must be damaged, and your protein intake must be sufficient to build new tissue. Resistance training is one of the most effective ways to trigger this state.
The amount of muscle you gain from weightlifting depends on several different factors, including the frequency and intensity of your training sessions. To maximize muscle growth, scientists recommend exercising at least twice a week and using weights ranging from 70-90% of your one-rep max at least once. Numerous studies have shown that prolonged infection and inflammation can also decrease the rate of muscle protein turnover, as can drinking excessive alcohol or not getting enough sleep.
#### How Much Protein Do You Need to Build Muscle?
The amount of protein you need to build muscle largely depends on body weight and activity levels. Since body weight tends to be the most important factor, recommendations are usually given in grams of protein per pound or kilogram of body weight. However, scientists do not agree on the adequate amount of protein. For athletes, the American College of Sports Medicine suggests consuming 1.2-1.4 grams of protein per kilogram of body weight to maintain muscle mass and recover from training. Recommendations from the International Society of Sports Nutrition are higher - up to 2 grams of protein per kilogram. According to a meta-analysis published in the British Journal of Sports Medicine, consuming more than 1.6 grams of protein per kilogram does not provide any additional benefits.
It is noteworthy that when it comes to protein intake for muscle building, quality may be just as important as quantity. Protein molecules consist of 20 different types of amino acids, nine of which are essential, meaning our bodies cannot produce them. To grow new muscle fibers, all these amino acids must be present in sufficient amounts. Animal foods are considered complete protein sources because they contain enough of all the amino acids. However, it is not necessary to consume meat to get protein. If planned carefully, vegetarian diets can provide the same results, according to the journal Nutrients. It has also been suggested that branched-chain amino acids (BCAAs) like leucine, valine, and isoleucine may be more effective at building muscle than others.
