Depending on the sport, athletes may need to adjust their macronutrient intake – especially when it comes to carbohydrates and protein.
Carbohydrates, protein and fat are referred to as dietary macronutrients. “Macro” means large, and we need relatively more of these nutrients than the “micronutrients” – vitamins and minerals. The amount of the different macronutrients that athletes need varies on the type and intensity of activity they are engaging in. Here’s a quick rundown on what athletes need to know about their macros.
Carbohydrates serve as the main source of fuel during exercise, which is why it’s so important for athletes to consume adequate amounts. This ensures that they have readily available carbohydrate stores in the muscle, liver and bloodstream. A well-balanced diet that supplies about half (45 to 55 percent) of the calories from carbohydrates should be adequate for most moderately active people. But, endurance athletes may need proportionately more (in the range of 55 to 65 percent of total calories) while ultra-endurance athletes (those who participate in events lasting longer than 4 hours) need even more – up to 75 percent of their total calories from carbohydrates.
Sports dietitians prefer to calculate carbohydrate needs according to body weight rather than a percentage of calories because it gives the athlete a specific intake goal. For general training, athletes are advised to take in 5 to 7 grams of carbohydrates per kilogram of body weight (or about 2.5 to 3 grams per pound). Endurance athletes (runners, cyclists, swimmers) need more – the goal is 7 to 10 grams of carbohydrate per kilogram of body weight (roughly 3 to 4.5 grams per pound). Ultra-endurance athletes, who engage in competitions that last for four hours or more, may need 11 grams or more per kilogram of body weight (5 grams per pound).
Protein supports exercise, but not by serving as a primary fuel source. It has too many other more important functions in the body. Of course, dietary protein is needed for muscle repair and growth, but it is also needed to make enzymes – proteins that assist with thousands of chemical reactions that take place in the body, including the production of energy from food. Hormones, such as insulin and glucagon that help to regulate the levels of sugar in your blood, are made from the amino acids in the proteins that you eat. And, your body uses the protein in your diet to manufacture antibodies – proteins that help your body fight infection.
Recommended protein intakes are often expressed as a percentage of total calories, and a well-balanced diet should supply protein in the range of 20 to 30 percent of calories. But sports nutritionists prefer to calculate protein needs according to body weight, just like carbohydrates.
It should make sense that athletes require more protein than sedentary people since they generally have more muscle mass. The recommended protein intake for endurance athletes is in the range of 0.5 to 0.6 grams per pound of body weight. Strength athletes need a bit more and are advised to take in about 0.7 to 0.8 grams per pound of body weight. That means that a 180-pound athlete might need about 90 and 110 grams per day to support endurance activity, or roughly 130 to 150 grams a day to support strength training.
Ideally, though, protein intake would be tailored to the amount of lean body mass (LBM) you have. Your LBM comprises all your body weight that isn’t fat – your muscles, bones, organs, tissues and water. Body composition testing can determine your LBM, and athletes are advised to take in about 1 gram of dietary protein for each pound of lean mass. Strength athletes may need a bit more.
Dietary fats supply the body with essential fatty acids, which means your body can’t make them, so you have to consume them. They’re an important part of the structure of every cell in your body and serve as a valuable energy source during activity.
Rather than suggesting a precise amount of fat for athletes, sports nutritionists usually recommend an intake of around 25 to 30 percent of their total calories – the amount that’s recommended for the general population. Since carbohydrate and protein intakes are more specific, once those intake targets are met, fat intake tends to naturally fall within the recommended range. And, like the general population, athletes are encouraged to select mostly unsaturated fats from foods like nuts, seeds, avocados, fatty fish and oils such as canola and olive.
While carbohydrates are considered the body’s primary fuel source, the body uses both carbohydrates and fat as fuel, depending on the intensity and duration of the activity. When exercise intensity is light to moderate, fat supplies about half of the body’s energy needs – especially as the duration increases. For example, after jogging for more than 20 minutes at a moderate pace, fat becomes increasingly more important than carbohydrates for sustaining activity.
Keeping your macros in the right balance is critical for good performance, and athletes would be wise to avoid dietary trends that upset this balance.