I’m sure that most people reading this newsletter are well aware that eating protein is good for muscle development. When talking about protein intake and muscle gains, the focus is usually on muscle growth, specifically looking at how much protein you need to maximize gains. In the last decade or so, we have gone from the classic old-school overkill recommendation of 1g of protein per pound of body weight to the now evidence-based recommendation of ~1.6g of protein per kilogram of body weight, with higher intakes not offering a meaningful benefit and with slightly lower intakes not necessarily being deleterious for your gains. There are some minor terms and conditions as it pertains to older adults, but overall, 1.6g of protein per kilogram of body weight seems to be a solid maximization recommendation for protein and muscle growth, even when following a plant-based diet.
However, there are many people who don’t necessarily care only about muscle growth and are more strength-oriented. I know that at least a few of you reading this are. This begs the question: Is there a dose-response relationship between protein intake and strength gains? It may be that, although muscle growth benefits cap at roughly 1.6g of protein per kilogram of body weight, higher protein intakes can lead to even greater strength gains. It may also be that you don’t necessarily need as much protein to maximize strength adaptations as you do for muscle growth. After all, training for maximum strength gains ≠ training for hypertrophy gains.
Thankfully, a 2022 meta-analysis looked at the “synergistic effect of increased total protein intake and strength training on muscle strength.”
The authors specifically looked at randomized controlled trials that included healthy adults, supplemented their protein intake for ≥ 2 weeks, and did not have a between-group comparison for different conditions other than nutrition (e.g., different exercise interventions). In total, the authors looked at 82 studies: 59 that included some form of resistance training and 24 that did not, with a total of 3940 participants.
The authors found that, similar to muscle mass, ~1.5g of protein per kg of body weight was required to achieve “the optimal effect on muscle strength.” Interestingly, protein intakes ≥2g resulted in ~5-8% less strength gains than 1.5g, but I personally wouldn’t think much about these findings, especially given the previous literature on the topic.
Lastly, higher protein intakes did not seem to increase strength to a meaningful extent when combined with no resistance training (shocker, I know).
Overall, things are looking good for lifters worldwide. Pretty much the same recommendations for muscle mass allow you to also maximize strength gains, with the data also showing that even if you consume less than that, your gains are likely not going to be heavily affected. At the end of the day, training remains the most potent stimulus for muscle gains, and even if there are days where you cannot really hit the “optimal” protein target, it’s definitely still worth getting your training in.
