The Most Important Nutrients for Athletes (or Working Out)

If you’re an athlete, or lead a very active lifestyle, you already know that the foods you eat affect your performance. But getting the most out of your workouts means more than just skipping donuts and eating more chicken breasts. To get the most out of your workouts, both before and after you hit the gym, it’s important to get enough of the right nutrients.

These are the most important—and often overlooked—nutrients that avid exercisers need to stay on top of their game:

B vitamins

B vitamins are responsible for helping your body turn the food you eat into fuel and form red blood cells, which carries oxygen to your cells. making them high on the list of nutrient must-haves for athletes. There are eight different B vitamins in the Vitamin B complex, and the most important ones for active individuals are B6 and B12.

If you exercise regularly or participate in sports, a Vitamin B deficiency can seriously hold you back. One study from Oregon State University found that active people with Vitamin B deficiencies perform worse during high-intensity activities and are unable to repair their muscles as efficiently.

Recommended intake for adults (per day): B12 – 2 micrograms; B6 – 1.1 micrograms

Best sources: Lean meats like chicken and turkey, tuna, salmon, lentils, and brown rice


Yes, sodium gets a bad rap these days. While too much sodium can be harmful to your health, not enough sodium during activity can also be harmful, especially during endurance events like marathons or triathlons. In severe cases, lack of sodium can result in hyponatremia, which can lead to fatigue, lethargy, headaches, and even comas.

If you’re doing long workout sessions, particularly in hot or humid weather, make sure to keep an electrolyte beverage at hand to rehydrate both fluids and sodium.

Recommended intake for adults (per day): 1500 milligrams
Best sources: Salt, salty foods, coconut water, sports drinks like Gatorade or Powerade, salted nuts


If you’ve ever run a 5k or marathon, you’ve probably been greeted at the finish line with bunches of bananas. That’s because they’re loaded with potassium, an essential electrolyte (and avid exerciser’s BFF). Potassium and sodium work together to balance fluids and electrolytes in the body. When potassium levels become unbalanced, muscle cramps and bloating can result.

Most people who eat a balanced diet (including a variety of fruits and veggies) get enough of the recommended 4,700 milligrams. If you’re going to be doing an intense workout or long run, add an additional 300 milligrams to replace what you’ll lose during 1-2 hours of intense exercise.
Best sources: baked potatoes, sweet potato, dark leafy greens, avocado, lentils, bananas, milk, carrots


Another nutrient that tends to get a bad rap, carbohydrates are responsible for providing energy to your hard-working muscles. Limiting carbohydrates can negatively affect your performance during high intensity exercise. In fact, one study of Cross Fit athletes showed that those who reduced their carb intake also reduced their performance ability.

It is recommended that 45 to 65 percent of your daily calorie intake comes from carbs, depending on your activity level.

Best sources: sweet potatoes, root vegetables, oatmeal, brown rice, quinoa and all whole grains


It turns out milk really does do a body good—especially if you’re an active woman. The calcium and other nutrients in milk help strengthen bones, preventing osteoporosis and helping balance hormone levels. Calcium can even prevent muscle cramps.

For those of you who don’t consume dairy products, (don’t worry) many plant based foods are also rich in calcium.

Aim for 1,000-1,300 milligrams of calcium each day.

Best sources: dairy products, calcium-fortified OJ, dark leafy greens, okra, and soy-products (tofu, soybeans, soynuts, etc.)

Vitamin D

Also known as the Sunshine Vitamin, vitamin D and calcium go hand in hand. Vitamin D promotes calcium absorption in the body and blood and is essential for healthy skeletal development. It’s also important for muscle development and has been shown to battle inflammation after high-intensity exercise.

The recommended amount of vitamin D is 600 IU per day. The tricky part is that few foods naturally contain vitamin D. But that doesn’t mean you should hit the tanning beds. Fatty fish like salmon and tuna contain the most vitamin D, and many foods (particularly milk) are vitamin D fortified.

Best sources: tuna, salmon, fish oils, fortified orange juice, fortified milk


This essential mineral found in the blood is responsible for making hemoglobin, which carries oxygen to your body’s tissues and muscles. Without enough iron, you run the risk of developing iron-deficiency anemia, which causes fatigue. Additionally, lack of iron means oxygen isn’t transported as effectively to your muscles, which can lead to a build-up of lactic acid and muscle cramps—every exerciser’s worst enemy.

Iron deficiency is common among female athletes (studies have indicated over 50 percent have depleted iron stores), so it’s important to get the recommended 18 milligrams per day if you’re between 19 and 50. Women over 50 require just 8 mg per day, while pregnant women require 27mg.

Best sources: Beans, lentils, nuts, dark leafy greens, egg yolks, lean red meats, whole grains


Want to keep your energy and endurance levels high for your workouts? Then make sure you’re getting plenty of zinc. This study from the Department of Agriculture showed that a lowered zinc intake lowered the oxygen uptake in athletes, leading to faster fatigue. Zinc is also crucial for keeping the immune system functioning at peak performance.

Aim for the recommended 8mg each day if you’re a woman, or 11mg if you’re a man.

Best sources: legumes, nuts, seeds, oysters, lean red meats, poultry, quinoa and other whole grains


Whether you’re an Olympic athlete or a channel surfer, water is absolutely essential for proper health. It is the most important nutrient in the body, and the most plentiful—the brain is composed of 95 percent water, and the blood is 82 percent water. Water keeps the entire body functioning properly, making bones and joints stronger, maintaining digestive health, reducing fatigue, and even helps you build muscle and lose weight.

Depending on your weight and perspiration rate, you lose about four cups of water for each hour you intensely exercise, which can negatively impact your performance. The best way to stay hydrated—and operating at peak performance—is to drink water before, during, and after exercise. The recommended daily amount for inactive individuals is 48-64 ounces per day. When exercising or playing sports, aim for at least 1-2 gallons.


Protein is the building block of muscle. It helps repair and strengthen muscle tissue that is lost during exercise and other physical activity. It also helps you lose weight. One study found that dieters who increased their protein intake by 30 percent lost 11 pounds in 12 weeks without making any other changes to their diets.

Athletes and avid exercisers should aim for 1-2 grams of protein per kilogram of body weight. Lean meats like chicken, fish, and turkey are good sources of protein, as are eggs, dairy and soy. Protein powders can also be used to meet very high protein requirements or to help make meals higher in protein. Vegans or vegetarians can get recommended protein amounts through high quality sources like nuts, beans, soy/tofu, quinoa and other whole grains, and even plant protein powders.

By eating the right nutrients, you’ll have the energy and stamina needed to power through your workouts while feeling your best both on and off the field, gym, or yoga mat!


Written By: Jill Overmyer

Edited and Fact-Checked by: Scarlett Full, in-house Registered Dietitian

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