With vast information available for the general population, endurance athletes, and resistance training athletes, protein recommendations can get confusing.
Suggested daily protein intake for endurance athletes ranges between 1.2 and 2.0 grams per kilogram of body weight per day based on AND and ACSM recommendations, and between 1.4 and 2.0 grams per kilogram of body weight per day based on ISSN recommendations.
While resistance training athletes might need higher protein intake on occasion, endurance athletes are typically better off using the ranges provided above, while also meeting daily carbohydrate and overall caloric needs to support training and recovery. However, higher protein intake just above ~2.0 g/kg per day might also be beneficial for endurance athletes during particularly hard training blocks or after a demanding event. Athletes who are in a hypocaloric diet for fat loss may also benefit from eating near the high end of the recommended protein range to help with maintaining lean body mass.
Timing of protein intake and protein dose per serving should also be considered. It has been suggested that older athletes might benefit from more protein per serving (about 40 grams instead of 20 grams), particularly in the post-exercise recovery window. Some athletes may also find that a pre-sleep protein snack of about 30-40 grams of whey or casein protein helps recovery and sleep. While it has been widely recommended to space out daily protein intake evenly across meals throughout the day, a recent study has brought forth some new considerations, finding no limit to the amount of protein used for protein synthesis during a 12-hour recovery period when comparing a 25-gram dose to a 100-gram dose of milk protein in resistance-trained young males.
Practically speaking, however, consuming 100 grams of protein in a meal would be difficult, and for an endurance athlete, this would likely also imply a decrease in the amount of carbohydrates and associated micronutrients. The study results do suggest, however, that an athlete does not need to limit protein intake to 20-25 grams out of fear that it might go unused. For example, consuming 2 meals containing 45 grams of protein may be just as effective as 3 meals providing 30 grams of protein.
While not always necessary, it still makes sense for endurance athletes to generally space protein out in order to meet other macronutrient needs, facilitate comfortable digestion and carbohydrate availability around training, and to optimize recovery and satiety throughout the day. Meeting total daily protein needs is still likely the most important factor for optimizing muscle protein synthesis and recovery.
One other consideration for maximizing protein synthesis is the quality of the protein being ingested. Higher-quality proteins have high essential amino acid (EAA) content (about 10 grams), high leucine content (about 3 grams), and high bioavailability of the amino acids in each serving. While it is possible to meet daily protein requirements through the consumption of whole foods, supplementation is often a practical way of ensuring adequate protein. Supplementation may be particularly useful for endurance athletes who have high protein needs, busy schedules, high training volumes, and/or dietary restrictions or preferences.
What are some of your favorite higher protein foods? Mine include beans and lentils, salmon, nutritional yeast, Greek yogurt, cottage cheese, tofu, and Fluid's 100% Whey Isolate.