Essential Nutrients for Athletes: A Breakdown and Their Functions
Published: 09/01/2025
Athletes push their bodies to the limit. To perform at their absolute peak, they need the right fuel, not just the right gear. The right sports nutrition regime can give athletes the energy they need to perform, help them recover faster and boost their overall strength.
Read on to find out about the essential nutrients athletes need and the benefits they deliver.
This article is a guide only. For personalised advice, consult your doctor, a sports nutritionist, or a dietitian.
Carbohydrates for fuel
We need carbs! Carbohydrates are the main source of energy for athletes. They are the fuel your body needs for intense and prolonged workouts.
The body stores carbs as glycogen in muscles and the liver. Glycogen is the most readily available energy source for working muscles.
Athletes need more carbs than non-athletes. The exact amount depends on the type and intensity of their sport. For example, endurance athletes, like marathon runners, may need up to eight to 10 grams of carbs per kilogram of body weight daily.
There are two types of carbs: simple and complex.
Simple carbs, like those in fruits and sports drinks, provide you with quick energy. They're useful right before or during exercise.
Complex carbs, found in whole grains and starchy vegetables, offer longer-lasting energy. You can get them from your daily meals and pre-exercise fueling.
Good carb sources include:
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Whole grain bread and pasta
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Brown rice and quinoa
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Oatmeal and other whole-grain cereals
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Fruits like bananas, apples and berries
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Starchy vegetables like potatoes, sweet potatoes and corn
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Legumes such as beans and lentils
The best carbs come from whole food sources. These provide not only the energy you need but also the nutrient benefits that support overall health.
The building blocks of protein
Nearly everything is ‘high in protein’ these days, but why? Proteins help build and repair your muscles and other important body tissues. Protein is also key for recovery after a long run and building your strength over time.
Strength athletes need 1.2 to 2 grams of protein per kilogram of body weight daily. So, a 70 kg athlete might need 84 to 140 grams of protein each day, for example.
This is higher than the generally recommended 0.8 grams per kilogram per person. Endurance athletes also tend to need less protein than strength athletes.
You should spread your protein intake over the course of a day. Eating protein before and after workouts can help you with muscle recovery and growth. Some studies suggest consuming 20-30 grams of protein soon after exercise is ideal for repairing your muscles.
Good protein sources include:
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Lean meats (chicken, turkey, lean beef)
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Fish and seafood
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Eggs
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Dairy products like milk, yoghurt and cottage cheese
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Beans and lentils
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Nuts and seeds
Plant-based athletes can meet their protein needs with legumes, grains, nuts and seeds. You might need to pay extra attention to make sure you’re getting all the essential amino acids you need.
Key vitamins and minerals for athletic performance
Athletes need a range of vitamins and minerals to support their active lifestyles. A balanced diet usually will already cover many of your needs. However, athletes who train intensely might need more of the following vitamins and minerals:
Vitamin D
This vitamin helps absorb calcium, which is key for strong bones. It also keeps muscles working well and supports the immune system.
You can get vitamin D from foods like fatty fish, egg yolks and fortified foods. Spending time in the sun also helps your body make vitamin D.
B Vitamins
B vitamins help convert food into energy. They're important for athletes because they help your body use energy and build healthy red blood cells.
Key B vitamins include B6, B12 and folate, which all help keep the body energised. Good sources of B vitamins include whole grains, lean meats, eggs, leafy greens and legumes.
Iron
Iron helps carry oxygen to muscles, which is especially important for endurance athletes. Female athletes and vegetarians might need extra iron - females due to losing blood (which contains iron) through periods and vegetarians as meat is a main source of iron. Iron deficiency can lead to fatigue and decreased performance.
Great sources of iron include lean red meat, poultry, fish, beans, lentils and fortified cereals. Vitamin C helps iron absorption, so pairing iron-rich foods with fruits or vegetables is smart.
Calcium
This mineral is crucial for bone health and muscle function. It also plays a role in nerve transmission and blood clotting.
Dairy products are rich in calcium and you can also find it in leafy greens, fortified plant milks and some types of tofu.
Magnesium
Magnesium supports muscle and nerve function. It also helps with energy production and protein synthesis.
Nuts, seeds, whole grains and leafy greens are rich in magnesium. Some athletes, especially those who sweat a lot, might need extra magnesium. If you sweat a lot, it may also be worth checking if other running clothes provide extra breathability.
Zinc
This mineral supports your immune function and helps your wounds to heal faster. It's also involved in many important enzyme reactions in the body.
As with magnesium, athletes might need more zinc due to losses through sweat. Good sources include meat, shellfish, legumes and nuts.
Taking care of your body
A balanced diet with the right mix of carbs, proteins, fats, vitamins and minerals is key for athletic performance. Proper hydration and nutrient timing also play important roles.
The right athlete nutrition is unique to each individual. When creating a fitness plan for yourself, take into account the activities you take part in, your body size and how hard you train. For personalised advice, consult your doctor, a sports nutritionist, or a dietitian.
