With so much focus on the right way to exercise, it’s easy to forget that nutrition is as important as how much weight you lift or how you train. For muscles to grow, muscle cells must lay down new contractile fibers that thicken the muscle fibers and increase their size. Exercise is a stimulus for muscle growth, but you also need amino acids, the building blocks of protein, to build those fibers.
Muscle protein synthesis allows your muscles to grow, and it’s counterbalanced by muscle protein catabolism, the breakdown of muscle tissue. For muscles to enlarge, muscle protein synthesis must exceed muscle protein breakdown. That’s why there’s so much emphasis on supporting muscle protein synthesis and reducing muscle breakdown.
Stimulating muscle through resistance training is one way to boost muscle protein synthesis, but nutrition matters too. Let’s look at some nutritional strategies for boosting muscle protein synthesis to enhance muscle growth.
Consume Protein with Each Meal
Protein supplies the amino acid building blocks that muscles need to repair and generate new muscle. However, you can only utilize so much protein at one time. The amount you can use at one time is between 20 and 30 grams of protein. If you’re getting most of your protein at a single meal, your body isn’t using all of it to build muscle. Therefore, rather than drinking a high-powered protein drink one time each day, it’s better for muscle growth to eat 20 to 40 grams of protein at each meal, so you know what you consume goes to muscle protein synthesis.
Consume Protein after a Workout
After a workout, your muscles need amino acids to start the repair process. As muscles repair the microtears created by a workout, they also build new tissue. At one time, people believed that the window period for getting protein after a workout was short and you need to consume protein within 30 minutes after a workout. However, research now shows the window period is longer. You can get a significant bump up in muscle protein synthesis by consuming protein within two hours after a workout. Again, the optimal amount is around 30 grams of high-quality protein.
Consume Carbohydrates to Maximize Muscle Protein Synthesis after a Workout
Protein is only part of the muscle-building equation. Consuming carbohydrates after a workout helps you better make use of the protein you take in. When you eat or drink carbohydrates, it stimulates insulin release and insulin helps get amino acids get into muscle cells where you can use them to build muscle tissue. When you eat a carbohydrate snack, it replaces glycogen stores, but the insulin release also helps your muscle cells gain access to the amino acids from protein. The ideal ratio of carbohydrates to protein in a post-workout snack is around 3 to 1.
Don’t Restrict Calories
Even if you consume enough protein, consuming calories below the level you need for maintenance can interfere with muscle growth. A 2014 study found even a short-term decrease in calories below maintenance reduces muscle protein synthesis after a meal. That’s why it’s difficult to “diet” to lose weight and build muscle at the same time. Calorie restriction makes it harder to build muscle. In fact, you need a slight calorie surplus to maximize muscle protein synthesis.
Consume Protein Before Sleep
The longest most people go without food is during sleep, so there are benefits to giving your muscles a shot of protein before bedtime to keep them in an anabolic state. A 2012 study found that consuming 40 grams of protein before bedtime boosted muscle protein synthesis during sleep. The best form of protein is casein, since your body absorbs it more slowly and levels of amino acids stay higher throughout the night relative to whey protein. Research shows casein before bed enhances muscle protein synthesis during sleep.
There’s also some evidence that protein before sleep boosts resting metabolic rate. However, consuming protein prior to slumber if you aren’t physically active could have a negative effect on your body composition. Casein increases insulin, and if you aren’t exercising to put that protein to use, the insulin may increase fat storage and lead to a gain in body fat. Exercise increases muscle sensitivity to protein for up to a day after a strength-training workout, so there’s less risk of fat gains.
Consume Leucine-Rich Foods
Leucine is a branched-chain amino acid, and it’s the most potent stimulator of muscle protein synthesis. Beyond being a source of an amino acid, it acts as a signaling molecule to activate the muscle protein synthesis machinery. Animal-based foods, like chicken, beef, and pork, are the best sources of leucine, although eggs, milk, beans, seeds, and soy foods contain leucine too. Leucine supplements are also available or you can take a branched-chain amino acid supplement that also contains isoleucine and valine.
The Bottom Line
If you’re trying to build muscle size, make sure you’re eating a balanced, nutritious diet and consuming enough calories. Also, be sure to consume the right amount of protein at the best times–after a workout, at meals, and before bedtime. Don’t overdo it, though. There’s no evidence that consuming over 40 grams of protein at one time boosts muscle protein synthesis more. Small quantities of protein and not all at the same time is the best approach.
Don’t neglect the basics either. You need adequate sleep and stress management to keep your body out of a catabolic state that will work against your goal of building muscle. Keep your body well fed and your training balance and you’ll have an easier time building muscle.
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