Home » Nutrition for Athletes Part 1: Day-to-Day

Nutrition for Athletes Part 1: Day-to-Day


Submitted by: Amy Sercel MS RD CD

Edited by: Marcia Bristow MS RDN CSSD CD

Whether you’re a casual athlete or someone who takes competition seriously, there’s no doubt that you always want to do your best.  You’re likely already aware that eating well helps you stay energized during activity, but the food you eat on a day-to-day basis also plays an important role in athletic performance.

Your Energy Needs

First and foremost, make sure you’re eating enough calories to fuel your activities, prevent weight loss, maintain your muscle mass, and keep your body working properly.  Eating regular meals and snacks is the best way to meet this goal.  Your daily calorie need depends on your height, weight, age, gender, and activity level.  You need to eat more calories as your activity level increases, and men usually need more calories per day than women.  You can roughly estimate your calorie needs by multiplying your weight in kilograms by a set number of calories per kilogram.  You can find your weight in kilograms by multiplying your weight in pounds by 0.454.  For example:

  • A woman who trains five days per week would need about 37 calories per kilogram of body weight to maintain her weight.  At 140 lbs, this woman would need about 2,350 calories each day.1
  • A man who trains five days per week would need about 41 calories per kilogram of body weight to maintain his weight.  At 160 lbs, this man would need about 2,980 calories each day.1
  • If you increase this training schedule to rigorous training nearly every day, the 140-lb woman would need about 40 calories per kilogram, or about 2,600 calories each day.1
  • A 160-lb man who trains rigorously every day would need about 45 calories per kilogram, or about 3,270 calories each day.1

If you would like to know exactly how many calories you need each day, meet with a Registered Dietitian who can calculate your daily energy need more precisely.  You can also use this interactive tool to estimate your daily energy needs based on your age, height, weight, and activity level.


In addition to getting enough calories, you need to eat enough carbohydrates every day.  Carbohydrates provide fuel for your muscles and brain, and if you don’t get enough you will feel tired, have trouble concentrating, and find exercise to be more challenging.  As a result, you won’t be able to perform at your peak.2

After you eat carbohydrates, they’re broken down into glycogen, which is stored in your muscles and liver.  During exercise, your body breaks down the stored glycogen to use as energy.  As with calories, the amount of carbohydrates you need to eat each day varies depending on your activity level and body weight.  Low-intensity exercise does not use a lot of stored glycogen, so someone who plays a sport such as golf or baseball would only need about 5-7 grams of carbohydrate per kilogram of body weight each day.  For a 160-lb man, this would mean eating between 363 and 508 grams of carbohydrates each day.  On the other hand, a distance runner, swimmer, or cycler would need about 8-10 grams of carbohydrate per kilogram of body weight to replenish the glycogen that gets used up during periods of intense activity.  For a 160-lb man, this would mean eating between 580 and 720 grams of carbohydrates per day.1

Sources of carbohydrates include fruits, vegetables, dairy products, beans, and grains.  These foods are considered nutrient-dense because they also provide vitamins, minerals, and fiber.  Soda, desserts, and candies also provide carbohydrates, but these are considered energy-dense because they provide calories without many other nutrients.  It’s best to include 2-3 servings of nutrient-dense carbohydrates with every meal and snack to ensure that you’re getting enough vitamins, minerals, and fiber each day.


Athletes also need to make sure they’re meeting their protein needs each day.  Although non-athletes are only recommended to get about 0.8 grams of protein per kilogram of body weight each day, athletes need more protein to ensure that their muscles can repair themselves after exercise.2 Endurance and strength athletes who are in their competitive season need between 1.2 and 2.0 grams of protein per kilogram of their body weight.1 For a 160-lb man, this would mean eating between 87 and 145 grams of protein each day.  A Registered Dietitian will be able to tell you how much protein you need to eat every day, based on your training level and health goals.

Good sources of protein include dairy products, eggs, lean meat, poultry, seafood, nuts, beans, and soy products.  You should make sure to include 1-2 servings of protein in every meal and snack.  You also need to make sure that you’re meeting your body’s carbohydrate needs so the protein you eat will be used for muscle repair, rather than energy.


It’s also crucial to include sources of healthy fats throughout the day.  Fat provides calories, helps maintain your cell membranes, and allows you to absorb the fat-soluble vitamins A, D, E, and K.  If fewer than 20% of your calories come from fat, it is likely that you aren’t absorbing enough of these vitamins.2 It’s recommended that athletes get about 1 gram of fat per kilogram of your body weight.  For example, a 150-pound athlete would need about 68 grams of fat each day.  Fat is found in a variety of foods, including whole grains, dairy products, beans, nuts, and meat, so as long as you’re eating a variety of foods from each food group you are probably getting enough fat.

It’s important to emphasize the unsaturated fats you can get from fatty fish, olive oil, nuts, seeds, and avocados, instead of the saturated fats you get from full fat dairy products, processed foods, and some meat.  Unsaturated fats help reduce inflammation in your body, whereas saturated fat can raise cholesterol levels and contribute to the development of heart disease.1


Drink water regularly throughout the day to make sure you’re well hydrated.  Keep in mind a formula to determine the amount of fluids you need to be well hydrated is approximately half your weight (in pounds) in ounces.  This means a 150-pound person should be drinking about 75 ounces per day.  This doesn’t include the amount of water you’ll need to replenish fluids lost during exercise.  To find out how much you need to drink in order to replace the fluids you lose in sweat, weigh yourself before and after exercise.  If you lose one pound, this means you’ve lost two cups of fluid and will need to drink this much to become adequately hydrated again.2

Planning Your Meals

In order to make sure you’re getting enough calories, carbohydrates, protein, and fat, you should eat regular meals and snacks.  Eating breakfast can give you the carbohydrates you need before an early morning training session, and can be a significant source of calories.  Make sure your breakfast is high in nutrient-dense carbohydrates and protein, and lower in fat, so you’ll feel full throughout the morning.  Eggs on whole grain toast with a side of fruit and a glass of low-fat milk is one nutritious option.3

Eating a balanced lunch can provide the carbohydrates and protein you need to recover from a morning workout or fuel up for an afternoon workout.  If you eat on the go, try packing yourself a sandwich made with whole wheat bread, lean meat, and a variety of vegetables with ¼ cup of trail mix on the side.3 Dinner is also a valuable way to refuel with nutrient-dense foods after a day of activity.

If your schedule is very busy, plan your meals for the day or week in advance, making note of times when you can prepare meals and choosing foods that you can easily reheat for lunch or dinner.  You can also pack snacks, such as fruit with nut butter, cheese sticks, or low-fat yogurt with granola, to make sure you always have food available throughout the day.  Make sure your snacks are “mini meals” that contain a combination of carbohydrates, protein, and fat, to help you stay satisfied and get a variety of vitamins and minerals.  It’s especially important to eat a snack within 30 minutes of training if you won’t be able to eat a full meal, since this will provide the carbohydrates and protein your body needs to recover from exercise.3

Your calorie and nutrient needs will vary depending on the intensity of your training and your overall health goals.  Including a balance of nutrient-dense carbohydrates, lean protein, and healthy fat in each meal will ensure that you are getting enough vitamins and minerals.  If your weight is remaining stable, you are likely meeting your energy needs each day.  If you’re concerned that you aren’t eating enough calories, or want to make sure you’re getting the right amounts of carbohydrates, protein, and fat meet with a Registered Dietitian who can provide you with an individualized meal plan.


  1.  Dunford M, Doyle JA. Nutrition for Sport and Exercise. 3rd ed. Cengage Learning; 2015.
  2.  Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet. 2016;116(3):501-528.
  3.  Sports, Cardiovascular, and Wellness Nutrition. Eating Frequency for the Student Athlete. 2013.

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