The Keys for Muscle Building

Submitted by Amy Sercel MS RD CD

Edited by Marcia Bristow MS RDN CSSD CD

“If some is good, more is better,” is an all-too-common trap, not least in the nutrition world.  Many people apply this idea to their food choices, especially when they’re trying to use their diet to enhance physical performance.  Many athletes include very large portions of protein-rich foods throughout the day to achieve muscle growth or boost their strength.  It turns out that an extremely high protein intake is really not necessary to get the results you may be looking for.

The average, minimally active adult needs about 0.8 grams of protein per kilogram of body weight to maintain overall health.  For a 150-pound person, this translates to a total of 55 g protein per day.  Some athletes more than triple that intake in an effort to build muscle, eating 3-3.5 grams of protein per kilogram of body weight each day!¹ These athletes are far exceeding their protein needs, and may be putting their health at risk.  In general, athletes need about 1.2-1.7 grams of protein per kilogram of weight to maintain muscle mass, or about 81-115 grams for a 150-pound athlete.  Ammonia is produced as a byproduct of protein breakdown, and when someone eats more than 2.5 grams of protein per kilogram of body weight each day, they risk maxing out their body’s capacity to safely get rid of that ammonia, which could lead the ammonia to build up in their blood.¹

In reality, someone who is trying to build muscle can expect to gain, at most, about 1 pound per week.  If this is a goal for you, you only need an extra 14 grams of protein per day.  This means the 150-pound athlete would need 95-130 grams of protein per day to build muscle.  An extra 14 grams of protein could come from 2 hard-boiled eggs, 2 oz of poultry or beef, 12 fluid ounces of milk, or ¾ cup of tofu.  At the same time, you’ll need about 400 extra calories per day, on top of what you need to maintain your current weight and activity level, to support muscle tissue growth, because muscle building itself requires energy.^1,2 

If you don’t know your daily calorie needs, you can use this calculator to get an estimate.  Once you’ve learned the amount you need to eat to maintain your weight and activity level, add about 400 calories to support muscle gain.  Since you’ll need an extra 14 grams of protein, about 60 of these calories should come from protein. 

A protein-rich post-workout meal or snack will help you build muscle mass by ensuring that your body has the building blocks available when muscle synthesis is triggered.  In one study, researchers compared the muscle mass of a group who consumed 10 grams of protein immediately after exercise and another group who had no post-exercise nutrition.  The group who ate a post-exercise snack gained muscle, while the group who didn’t lost muscle by the end of the study.²

Your diet is only half of the equation though.  In order to trigger muscle growth, you also need to engage in some type of strength training.  During strength training, the force on your muscles activates the genes that regulate muscle synthesis and trigger them to start making new muscle fibers.¹ Once they’re activated, your body will use the energy and protein from your diet to build muscle.  If you don’t have enough energy or protein available, your body will be unable to repair the tears that occurred during your strength workout, and you will likely experience some muscle loss.^1,2

There isn’t a clear consensus on the type of strength training that will result in the most significant muscle gains.  This is partially because muscle increases depend so much on individual body type, hormone levels, and genetics.¹ Some people recommend using higher weights and lower repetitions, while others suggest that the opposite type of lifting may be more effective.  One small-scale study of 15 men found that low-weight, high repetition training had a stronger impact on muscle growth because the cellular signals triggering muscle growth remained active 24 hours after the weight training session, while they only remained active for about 4 hours after the high-weight, low repetition session.³ More studies with a larger participant pool are needed before we can say for certain whether this advice applies to the entire population.

Another study examined frequency of training and found that people who completed nine sets (or cycles of unique exercises) over three days of the week gained the same amount of muscle as those who did all nine sets on one day and didn’t do any other strength training during the week. The researchers concluded that the total volume of training was more important for muscle growth than the frequency throughout the week.⁴

The main take-away is, if you want to build muscle you don’t need to take extreme measures in your diet and exercise.  Incorporate weight lifting into your typical workout routine each week, and make sure to include a post-workout meal or snack that contains a good source of protein.  Get an idea of the amount you need to eat to maintain your current weight, and add an extra 400 calories to that to support muscle growth.  If you’d like more support with meal planning and timing your nutrition around activity, or if you’ve made changes but aren’t seeing the results you expected, meet with a registered dietitian who can give you more specific, individualized advice.  The key to this long-term change is to stick with it and remember muscle growth won’t occur overnight. Be patient! 

References:

1.         Dunford M, Doyle JA. Nutrition for Sport and Exercise. 3rd ed. Cengage Learning; 2015.

2.         Weinert DJ. Nutrition and muscle protein synthesis: a descriptive review. J Can Chiropr Assoc. 2009;53(3):186-193.

3.         Burd NA, West DWD, Staples AW, et al. Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men. PLOS ONE. 2010;5(8).

4.         Thomas MH, Burns SP. Increasing Lean Mass and Strength: A Comparison of High Frequency Strength Training to Lower Frequency Strength Training. Int J Exerc Sci. 2016;9(2):159-167.