Can nutrition improve athletic performance?

By Perrin Braun, August 1, 2022


If you want to become faster, stronger, and more flexible, you need to pay attention to the food that you eat. Optimal nutrition is the key to peak performance on and off the field, because food provides essential nutrients to build and maintain a strong body.

“Biomechanical changes take time and persistence, but changes in diet can be made quickly and can have an immediate effect on how your body works,” says US Olympic triathlete.

He has used InsideTracker’s blood analysis to see what his biochemistry reveals about his health and performance. InsideTracker measures up to 43 biomarkers, objective. But that isn’t the best part, says Shoemaker. “InsideTracker provides suggestions for foods to eatnot just because somebody said so, but because your own body said so."


What are some of the most important nutrients for athletes?

The InsideTracker team analyzed thousands of peer-reviewed research papers to find the biomarkers that are the most critical to improving your physical performance. These are some of the biomarkers that are most essential for athletes, and the foods that you can eat to improve them: 


Hemoglobin is a protein that is partially composed of iron and mainly localized in the red blood cells, hemoglobin transfers oxygen to the muscles and other organs. Athletes who don’t have enough iron may have compromised athletic performance, a depleted immune system, and an increased susceptibility to illness, chronic fatigue, irritability, and a high exercise heart rate. To improve your iron levels, be sure to increase your intake of foods like red meat, rice, wheat, oats, nuts, dark leafy greens, and beans.

Creatine kinase (CK)

CK is a type of enzyme that is located in several tissues in the body, mainly in muscle. In normal conditions, there is a small amount of creatine kinase circulating in the blood, but when muscle damage occurs, CK leaks from the damaged cells and the amount of CK in the blood can rise substantially. Therefore, blood levels of CK act as an indicator to show muscle damage and the extent to which you are over-training. To help repair muscle damage and reduce high levels of CK, be sure you are eating enough lean protein, including soy, chicken breasts, and beans. 

Calcium and vitamin D

Low levels of each of these nutrients can increase the risk of low bone mineral density and stress fractures. Calcium plays an integral role in the growth, maintenance, and repair of bone tissue, maintenance of blood calcium levels, regulation of muscle contraction, nerve conduction, and normal blood clotting.

Vitamin D is essential for bone health because your body needs it to absorb calcium. It also regulates the development and maintenance of the nervous system and of skeletal muscle. New research indicates that vitamin D supplementation in ultra-marathon runners improves vitamin D status and may play an important role in preventing skeletal muscle injuries following activity eccentric muscle contractions. 

Dairy products like milk, yogurt, and cheese are rich in calcium, but leafy green vegetables (think kelp and spinach), and dried beans will also help to improve your levels. To increase your vitamin D levels, eat more fatty fish (such as sardines, mackerel, and salmon), egg yolks, butter, beef liver, cheese, and fish oil. Some foods, such as milk, yogurt, cereal, and orange juice, are now fortified with vitamin D; so check nutrition labels to find how much is in your favorite foods. 


What does a healthy diet look like?

Athletes need a combination of protein, fat, and carbohydrates in order to maintain peak performance. Here’s why:


 Your body needs lots of oxygen for endurance events, which is why your rate of respiration increases during exercise. Carbohydrates are one of the best sources of energy due to the efficient way they use oxygen. In fact, they use less oxygen for every kilocalorie of energy produced than fats or proteins, which make them an important food choice for athletes. Some good examples of meals and snacks that are high in carbohydrates include:

  • Apple + nut butter (1.5 large apples = 60g carbohydrates)
  • Overnight oats (3/4 cup oats + 1/2 banana = 60.5 g carbohydrates)
  • Tuna and crackers(1 cup whole wheat crackers = 50g carbohydrate)

Remember that not all carbohydrates are grain-based! Squash, potatoes, parsnips, carrots, and bananas are also good sources of energy.


Dietary protein is broken down into amino acids that assist with everything from digesting food to repairing body tissue. Carbs provide the body’s primary fuel while it is in motion: protein is important for post-workout recovery. You need protein to repair exercise-induced damage. Protein also helps to replenish depleted energy stores, preparing your body for its next bout of activity. While protein should be included in your post-workout meal or snack, most athletes eat an adequate amount without consuming protein bars or shakes, which also can contain high amounts of added sugars. 

Both plant-based sources of protein (such as beans, peas, nuts, and soy products) and animal-based sources (such as meat, poultry, seafood, eggs, and dairy products) can be part of a balanced diet. Try to add to your diet protein from seafood, which is rich in omega-3 fatty acids; as well as protein from cooked dry beans and peas, which provide ample dietary fiber. But don’t overdo protein. You need to maintain a ratio of carbohydrates to protein of about 3:1.


Hard-working muscles require the caloric energy that dietary fat provides (fats contain 9 calories per gram, compared with 4 calories per gram in carbohydrates and protein). Fat’s calorie density, along with your body’s nearly unlimited storage capacity for fat, makes it your largest reserve of energy. One pound of stored fat provides approximately 3,600 calories of energy! While these calories are less accessible to athletes performing quick, intense efforts like sprinting or weight lifting, they become essential for lower intensity and endurance exercise such as long-distance cycling and running. Fat is a critical source of fuel for endurance exercise; your body actually stores some fat in muscle fibers themselves. Recent studies have shown that regular endurance exercise increases the amount of fat stored within muscle fibers.



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