Traditionally, athletes looking to build muscle have stayed laser-focused on protein. Meanwhile, runners and cyclists focus more on carbs or fat to keep them powered through their respective workouts, often fearing protein will make them bulky and slow. But new research is showing that not only can every athlete improve their performance by consuming protein, but also by consuming way more of it than is commonly recommended.
Here's why: Amino acids in protein help repair your muscle fibers so they grow back bigger and stronger. It’s these same amino acids that allow protein to help your cardio fitness. Having a constant stream of essential and branched chain amino acids to your working muscles during high-intensity aerobic exercises helps to serve as an additional fuel source. Plus, protein does more than just repair your damage it is a building block for the whole body, not just muscles. More research is showing that the body draws from dietary protein to keep the immune system healthy, to produce new cells to replace worn out ones, and to make repairs to other tissues in the body. Because the body uses protein for other functions the recommended daily allowance may be low, especially for the developing athlete that is working hard but also growing.
How much protein you really need
The Academy of Nutrition and Dietetics recommends that athletes aim for roughly one gram of protein per kilogram of body weight per day to maintain muscle mass and .64 to .82 g per pound of body weight to build muscle. But the latest science suggests that every exerciser could benefit from hitting the upper end—or more—of that amount, not just those looking to add bulk.
In two separate studies, active men and women were put on a diet of .91 g/lb of protein a day. They spent 12 weeks doing a combination of resistance training, interval training, stretching, and endurance. The results: compared to controls who ate only .45 g/lb per day of protein, both sexes increased their muscular power and strength, with the men also increasing their aerobic performance and flexibility and the women their cardiovascular health and muscular endurance. The reason there was a difference between genders could be that men and women start from different baselines: Women are naturally more flexible and often do more cardio, so men have more room to improve in flexibility and aerobic endurance. Meanwhile, women have less lean muscle mass so when they start building more thanks to strength training and more protein, they show greater improvements in muscle endurance. Pushing it even further, a separate study in the American Journal of Clinical Nutrition found that men who were burning a ton of calories through three days of HIIT, two days of strength training circuits, and one day of plyometrics, gained more lean body mass and lost more fat eating 1.1 g/lb of protein a day.
But, there is a ceiling. Research in the Journal of the International Society of Sports Nutrition found that when active men and women kicked their daily protein intake up to 2 g/lb/d, they didn't see any positive or negative effects on their weight, lean body mass, or body fat percentage. Notice that they didn’t see any negative effects which is often a concern of some.
In the end, how much protein you should consume is super individual but the existing research points to starting with at least .9-1.0 grams of protein per pound of body weight a day.
This takes discipline and thinking forward since most athletes don’t get this much. Often this is the missing link to increasing athletic performance and it can be mastered with planning.