When you engage in resistance-focused exercise, like weightlifting, you create small tears in your muscle fibres, so what does your body do to repair these tears and ultimately build muscle?
Let’s talk about muscle protein synthesis and why it's so important for muscle gains (i.e. the reason why I keep telling you to eat your protein).
What is muscle protein synthesis?
Now back to that initial question. When you workout, you actually do create small tears in your muscle fibres. These tears cause your body to synthesize, or create new proteins to replace the damaged ones. Muscle protein synthesis is the way in which your body builds these new proteins in your muscles.
This process is essential for muscle growth, repair, and maintenance. If your body can't synthesize enough new muscle fibres to replace the damaged ones, your muscles won't grow or repair as effectively.
How does it work?
Muscle protein synthesis starts when your body receives a signal, usually triggered by resistance exercise and protein ingestion, to build new proteins, again, causing muscle growth, repair, and maintenance.
When you engage in resistance exercise, you activate certain signalling pathways that promote muscle protein synthesis. In fact, some studies have shown resistance training to promote protein synthesis twofold, following exercise, so get to the gym folks (2)!
Protein ingestion also stimulates muscle protein synthesis, as the amino acids in the protein provide the building blocks needed for protein synthesis.
How can I maximize it?
To maximize muscle protein synthesis, you need to consume enough protein and engage in resistance exercise regularly.
For resistance exercise, a 2012 study found that the magnitude of acute response of muscle to resistance exercise in terms of muscle protein synthesis is dependent upon both load and intensity. While there are no detectable increases in muscle protein synthesis at intensities of ≤40% 1-Rep Max, exercise increases muscle protein synthesis 2- to 3-fold at intensities greater than 60% 1-Rep Max (1).
However, lower-intensity exercise can yield anabolic effects when exercise is performed to failure, resulting in increases in muscle protein synthesis at 30% 1-Rep Max of comparable magnitude to a group performing 90% 1-Rep Max (1).
Consuming a high-protein diet provides your body with the essential amino acids it needs for muscle protein synthesis.
A 2018 review looked into over 30 studies and concluded that to maximize muscle growth, you should hit a minimum target of 0.18g/lb bodyweight per meal across a minimum of 4 meals in order to reach a minimum of 0.73/lb bodyweight (3).
The study also recommends an upper limit of 1g/lb/day spread out over 0.25g/lbs in the same 4 meals (3). Depending on your training goal, this means you’ll want to have approximately ¼-⅓ of your plate consist of high-quality protein.
If you’re struggling to hit your protein goal, incorporate more animal- and plant-based protein sources into your diet, like chicken, legumes, and whole wheats, and experiment with new recipes.
Eat your protein!
So there you have it – muscle protein synthesis is essential for the growth, repair, and maintenance of your muscle gains. If you want to maximize your muscle growth and repair, make sure to consume enough protein and engage in resistance-focused exercise regularly.
Need help getting to the gym?
When you’re busy, staying fit can get put on the back burner, causing your fitness goals to suffer. Discover how a certified personal trainer can help you stay on track with your fitness goals by visiting shifttostrength.com/onlinetraining today.
You can also find all our blog posts at shifttostrength.com/blog, or by clicking the button below.
Atherton, P. J., & Smith, K. (2012). Muscle protein synthesis in response to nutrition and exercise. The Journal of physiology, 590(5), 1049-1057.
Aragon, A. A., & Schoenfeld, B. J. (2013). Nutrient timing revisited: is there a post-exercise anabolic window?. Journal of the international society of sports nutrition, 10(1), 5.
Schoenfeld, B. J., & Aragon, A. A. (2018). How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition, 15(1), 10.