Three keys to build muscle and retain muscle

A study published in February 2018 has shed more light on how protein impacts muscle building and breakdown.1 Three main factors have surfaced: 

               1. The exercise you do (or don’t do)

               2. How much protein you eat 

               3. The quality of protein you eat


1. Weight training or cardio?

Most people understand that exercise is good for muscle health, but what does that have to do with protein? Exercise sensitizes your body to protein so that it is used more effectively.2,3,4 The opposite happens as you get older–your body is naturally desensitized so that you need to consume more for the same results.5

Researchers have shown that resistance exercise (think weight training) is the best form of exercise for building muscle, something that bodybuilders have known for years.32,33 Exercise performed at an intensity greater than 60% of a one-repetition max produces a 2-3 fold increase in muscle protein synthesis. On the other hand, at intensities less than 40% of a one-repetition max it is hard for researchers to detect an increase in muscle protein synthesis–unless the repetitions are performed to failure.34,35,36 Cardio (endurance-type exercise) is great for long-term health, but it will not maximize muscle growth like pumping iron.  


2. How much protein do you need?

Protein intake boosts muscle protein synthesis. The more you consume, the better your growth. But if you do not exercise, your muscle protein synthesis will plateau after consuming roughly 20 grams. Engaging in full-body resistance exercise lets your body take advantage of much larger amounts.6,7 Once your muscle protein synthesis is maxed out, additional protein can still help by inhibiting muscle protein breakdown.8,9 

Recreationally active individuals should focus on boosting muscle protein synthesis instead of suppressing muscle protein breakdown. Many researchers conclude that the optimal daily intake level is between 0.7 and 1.1 grams per pound of body weight.1,10,11


3. Protein quality also matters

Your body needs all nine essential amino acids to build muscle. These “indispensable” or “essential” amino acids cannot be made by the body, so they must come from your diet. Especially important is the essential amino acid leucine because it activates the muscle building process. Research has shown you need at least 1,700 to 2,400 mg of leucine to “switch on” muscle protein synthesis.12,13,14

Whey is arguably the best protein source due to its excellent essential amino acid profile, including its high leucine content. Animal or dairy-based proteins fall into this high-quality category because they contain all nine essential amino acids.15,16

Plant proteins typically lack one or more of the nine essential amino acids and typically have lower leucine amounts. Vegetarians can overcome this limitation this by combining different sources together, like pea and rice. If your plant protein blend does not contain pea, consider adding a vegan form of the amino acid leucine (2.5-5 grams) to your plant-based meal or protein shake.17 Pea is one of the few plant proteins with a high leucine content.


Some practical tips for day-to-day living

Here are a few practical ways to turn this knowledge into power, literally. Your approach should change depending on the goals you set.

Goal: Maximize muscle growth

Eat enough protein each day

Eat 0.7 to 1.1 grams of protein per pound of body weight each day.1 That’s 100 to 165g for a 150-pound person.

Eat enough protein each meal

If you don’t get enough protein each meal, you are not reaching your potential. An inferior intake at each sitting will result in submaximal muscle growth.18 The chart above shows what you should target based on your weight.

Eat protein before bed

Consume a larger amount 1-3 hours prior to sleep to offset declines in muscle protein synthesis that occur while sleeping.19-22

Lift weights

Perform resistance training exercises to build and maintain muscle.2,3,4 Endurance exercises are also good for cardiovascular health.


Goal: Retain muscle during weight loss 

Lift weights to retain muscle

Weight loss wreaks havoc on existing muscle. You must lift weights if you want to retain muscle during calorie restriction.23,24,25

Consume quality protein

For athletes or dieters “cutting” weight over an extended period of time, research shows whey is the best for appetite control (provide satiety) and help keep you from splurging.26,27,28 

Protein needs are higher when dieting

Your protein requirements are greater during calorie restriction than when maintaining weight. Increase your intake to between 1 to 1.4 grams per pound of body weight.29,30  That’s 150 to 210 grams a day if you weigh 150 pounds.

If you have a higher body fat percentage, aim for the lower end of this range. Leaner individuals with resistance-training experience are more vulnerable to losing muscle during calorie restriction. They should aim for the higher end of this range.31


In summary 

Engage in a resistance-exercise plan, whether that is weightlifting or bodyweight exercises. Each day, try to consume one gram of protein for every pound of your ideal body weight. If you are older or trying to lose weight, make sure you get slightly more.

Consume enough protein in each meal to produce a robust stimulus of muscle protein synthesis. Look for high-quality protein sources with all nine essential amino acids, such as whey, casein, egg, fish, poultry and other animal proteins.

If you are vegan, obtain your protein from a variety of sources to guarantee you are getting all nine essential amino acids. You may need to eat more total protein or add additional leucine to your diet to get the same results as with whey protein. 

Next Back to Top
More Related Articles