An athlete who is in training and weighs 70 kg should consume _____ g of protein daily.

The Institute of Medicine recommends adult men and women consume at least 56 grams and 46 grams of protein each day, respectively. Sprinters need additional protein to help repair their muscles in response to training. Getting recommended amounts of protein will help sprinters maximize their athletic performance; the amount of protein needed is based on a sprinter’s body weight.

Protein Recommendations

Researchers who conducted a study published in a 2006 edition of the “Journal of the International Society of Sports Nutrition” report that power athletes, such as sprinters, need 1.6 to 1.8 grams of protein per kilogram of body weight each day. This is equivalent to 0.73 to 0.82 grams of protein per pound of body weight. For example, a 130-pound sprinter needs about 95 to 107 grams of protein on a daily basis.

Maximum Beneficial Amount

Strength and power athletes, such as sprinters, may consume up to 2 grams of protein per kilogram of body weight, or about 0.91 grams of protein per pound of body weight each day. This is equivalent to about 118 grams of protein per day for a 130-pound sprinter. The 2006 study published in the “Journal of the International Society of Sports Nutrition” reports that protein intakes greater than 2 grams per kilogram do not provide additional benefits for strength and power athletes. In fact, a 2011 review published in “The Proceedings of the Nutrition Society” found that athletes who consume high-protein diets for a prolonged period of time may experience bone mineral loss or kidney damage.

High-Protein Foods

Consuming a variety of high-protein foods over the course of the day will help sprinters meet their daily protein needs. Examples of high-protein foods beneficial for sprinters include lean beef, un-breaded poultry without the skin, seafood, egg whites, soy products, low-fat dairy products, legumes, nuts and seeds.

Diet Composition

Carbohydrates are a sprinter’s main source of energy. In fact, the American Academy of Orthopaedic Surgeons recommends athletes consume 60 to 70 percent of their calorie intake from carbohydrates, 12 to 15 percent from protein and 20 to 30 percent of their energy intake from fat. Carbohydrates and protein each provide 4 calories per gram, and fat contains 9 calories per gram. Therefore, a sprinter consuming a 3,000-calorie diet consisting of 65 percent carbohydrates, 15 percent protein and 20 percent fat should consume 488 grams of carbohydrates, 113 grams of protein and 67 grams of fat each day.

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Some sports nutrition experts recommend a 60/20/20 diet. What’s that? It’s a diet where you get 60 percent of your daily calories from carbohydrate and 20 percent each from fat and protein. Advocates say endurance athletes need to consistently maintain this ratio of the three so-called “macronutrients” to perform optimally in training. Other experts recommend a more evenly balanced 40/30/30 diet. And still others promote different ratios. While they might disagree on the specifics, all of these experts agree that there exists some perfect balance of macronutrients that optimizes endurance-training performance. Guess what? They’re all wrong. (If you’d like to see carbs per kg of body weight breakdown, jump to the bottom.)

“Percentages are meaningless, because it is the absolute amount of carbohydrate and protein that matters,” said Asker Jeukendrup, Ph.D., an exercise physiologist at the University of Birmingham in England and one of the world’s leading experts on the effects of different amounts of carbohydrate and protein intake on endurance performance. “How much you need depends on your goals and the amount of training you do.”

In other words, what matters is not the relative proportions of carbs, fat, and protein you eat but the basic quantity measured as total calories or grams. And since macronutrient needs vary depending on training volume, there is no single macronutrient ratio that could possibly meet the needs of every athlete.

So what are the right amounts of grams per kilogram of body weight? “Typically, carbohydrate needs will vary from 5 to 10 grams per kilogram of body weight per day with training ranging from one hour per day to five hours or more,” said Jeukendrup. (Note that 1 kilogram is equal to 2.2 pounds).

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Unlike protein and fat, carbs are not used structurally in the body—they are used strictly for fuel. Therefore the more active you are, the more carbohydrate you need, with the hardest training athletes requiring twice as much carbohydrate as the lightest trainers. Studies have shown that athletes who fail to increase their carbohydrate intake sufficiently to match increases in their training volume do not perform as well.

Protein needs also vary with training volume, although somewhat less. Traditional recommendations are 1 gram of protein per body weight daily for recreational endurance athletes increasing to 1.5 grams per kilogram per day for serious competitors. (Also note that protein needs can vary for men and women.) But in one study, Jeukendrup found that going all the way up to 3 grams per kilogram per day helped a group of elite cyclists to better handle the stress of an especially hard block of training. This is an extreme case, but it demonstrates that the carbohydrate and protein recommendations for athletes should be considered minimums. It’s OK and sometimes beneficial to get more, as long as doing so doesn’t cause you to consume too many total calories.

RELATED: Triathlete’s Complete Guide to Fueling and Nutrition

And fat? Dietary fat needs are less sensitive to fluctuations in training volume. According to Jeukendrup, you can trust that your fat needs will be met if you get the right amount of carbs and protein and simply let fat account for the remainder of your daily energy needs.

Getting the right balance of macronutrients requires a little math of carbs per kg of body weight, but it beats using a one-size-fits-all formula that doesn’t really fit all.

RELATED: Ask Stacy: How Should I Time My Carbohydrate Intake Around Training?

Daily Carbohydrate Needs (Carbs Per KG of Body Weight)

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