Athletes require a precisely balanced nutrition plan that ensures optimal energy levels, muscle recovery, and long-term endurance. Their bodies need a higher amount of macronutrients – proteins, carbohydrates, and fats – than the average person, and micronutrients and targeted supplements can provide an additional advantage.

Modern sports science emphasizes individualized nutrition, combining whole foods with specialized supplements to support muscle function, hormonal balance, and optimal metabolism. A properly tailored nutrition regimen can be a decisive factor between average and top-level performance.

The following discusses which nutritional components are most important for athletes, how to combine them during different training phases, and which supplements can help achieve peak athletic form.

Macronutrient balance for athletic performance

Athletes must precisely balance the ratio of carbohydrates, proteins, and fats to maintain energy levels, muscle recovery, and overall physical capacity. Carbohydrates are the primary energy source, supporting glycogen stores in muscles. Proteins are necessary for muscle growth and regeneration, while fats provide long-lasting energy and help absorb fat-soluble vitamins.

Macronutrient proportions depend on the sport. Endurance athletes need more carbohydrates – about 55–65% of daily calories to maintain optimal glycogen levels. Strength athletes require a higher protein intake – 25–35% of calories to support muscle synthesis. Fats should make up about 15–25% of total calories, with a focus on healthy fats from nuts, avocados, and fish oils.

Targeted nutrient cycling helps optimize results. On intense training days, athletes should consume more carbohydrates to replenish glycogen, while on rest days, higher protein and healthy fat intake can aid recovery. It is important not only the amount of macronutrients consumed but also their distribution throughout the day, especially ensuring protein and carbohydrate intake before and after training.

Effective daily protein requirement fulfillment

Athletes must accurately calculate daily protein intake to support muscle recovery and athletic performance. Endurance athletes need 1.2–1.4 g of protein/kg of body weight per day to maintain muscle resistance and reduce catabolism. Strength athletes need 1.6–2.0 g/kg to achieve optimal muscle growth and regeneration.

The distribution of protein intake throughout the day is as important as the amount. Athletes should consume 20–30 g of protein per meal and ensure snacks with 10–15 g of protein, eating every 3–5 hours. After training, it is important to consume 0.25–0.3 g of protein/kg of body weight within the first two hours to maximize the muscle protein synthesis window.

Main protein sources:

• Animal-based: chicken, beef, fish, eggs, cottage cheese, Greek yogurt.
• Plant-based: lentils, chickpeas, tofu, quinoa, nuts.

Athletes may benefit from combining proteins with carbohydrates in a 3:1 or 4:1 ratio, as this improves glycogen recovery and reduces muscle breakdown. Although protein supplements can be useful, priority should be given to whole foods that provide additional micronutrients and bioactive compounds necessary for athletic activity.

Essential fats for athletes

Fats are a crucial energy source, especially in long-duration endurance sports such as marathon running or cycling. One gram of fat contains 37 kJ of energy compared to 17 kJ from carbohydrates and proteins, making fat metabolism critically important for low to moderate intensity training.

Besides energy supply, fats support hormone production, including testosterone and cortisol, which regulate muscle growth and recovery. They also strengthen cell membranes, support the nervous system, and protect organs through adipose tissue.

Best fat sources for athletes:

• Monounsaturated fats: olive oil, avocados, nuts.
• Polyunsaturated fats (Omega-3 and Omega-6): fatty fish (salmon, mackerel), flaxseeds, walnuts.
• Medium-chain triglycerides (MCT): coconut oil, MCT supplements – for faster energy release.

Recommended fat intake: 20–35% of daily calories, emphasizing unsaturated sources, limiting saturated fats to 10%, and completely avoiding trans fats, which can cause inflammation and slow recovery. Balanced fat consumption ensures long-lasting energy, hormonal balance, and better recovery, helping achieve top athletic results.

Benefits of beetroot juice for athletes

Beetroot juice can improve endurance and physical capacity due to its high concentration of nitrates. In the body, these nitrates are converted by oral bacteria into nitrites and then into nitric oxide, which dilates blood vessels, improves circulation, and increases oxygen delivery to muscles. For this reason, athletes can maintain higher intensity and use energy more efficiently during training.

Scientific research shows that beetroot juice can improve endurance performance by about 0.8%, and maximal oxygen uptake (VO2max) can increase by up to 4.82%. This effect is especially noticeable during high-intensity interval training and sprints. The optimally effective dose is recommended to be consumed 5-9 mmol of nitrates 2-3 hours before physical exertion.

To ensure maximum benefit, mouth antiseptics or tooth brushing should be avoided immediately after juice consumption, as this can reduce the ability of oral bacteria to convert nitrates into nitric oxide. Beetroot juice is a natural and effective way to increase endurance and training efficiency, making it a valuable part of athletes' nutrition.

How important is it to maintain fluid balance during training?

Fluid balance is a critical factor ensuring athletes' endurance, thermoregulation, and muscle function. Even a 2% loss of body mass in fluids can reduce physical capacity, and greater fluid deficits can cause fatigue, cramps, and decreased reaction time.

Drinking water strategy:

• Before training: 500–600 ml of fluids 2–3 hours before, 200–300 ml 10–20 minutes before.
• During training: 200–300 ml every 10–20 minutes, depending on sweating and ambient temperature.
• After training: 700 ml of water per kilogram of body weight lost.

For training sessions longer than 2 hours or in hot conditions, athletes should consume sports drinks with 6–8% carbohydrates and 30 mmol/l sodium, which help restore electrolyte balance and prevent hyponatremia.

Additional hydration tips:

• It is best to drink fluids at 10–15 °C, as they are absorbed faster.
• Monitor urine color – light yellow indicates proper hydration, darker color signals fluid deficiency.
• For rehydration after training, choose foods containing electrolytes, such as salted nuts, bananas, and sports drinks with carbohydrates.

Consistent fluid intake maintains optimal physiological condition, helps avoid fatigue, and supports maximal athletic performance.

Benefits and usage of creatine

Creatine is one of the most studied supplements that increases muscle strength, power, and explosive capacity. For athletes engaged in strength, sprint, and high-intensity training, creatine use can improve explosive power, short-term endurance, and overall performance.

Effects of creatine on athletic performance:

• Increases ATP regeneration, allowing muscles to generate more force during short intense intervals.
• Improves sprint speed and maximal strength development, especially for weightlifting, football, and cycling athletes.
• Reduces muscle fatigue and accelerates recovery between sets or repeated exercises.
• May help preserve lean muscle mass, especially during calorie deficit.

Optimal creatine dosage:

• Loading phase: 20 g per day (4 x 5 g) for 5–7 days or 0.3 g/kg of body weight.
• Maintenance phase: 3–5 g per day or 0.03 g/kg of body weight.
• Taking with carbohydrates may increase creatine absorption due to insulin-mediated uptake.

Additional tips:

• Drink enough water, as creatine retains fluids in muscles and may increase hydration needs.
• Long-term use is safe but recommended doses should be followed.
• Monohydrate is the most effective form of creatine with the strongest scientific backing.

Creatine is especially beneficial for strength and explosive energy athletes, providing significant advantages in muscle strength, recovery, and training productivity.

Beta-alanine for athletic performance

Beta-alanine increases carnosine levels in muscles, reduces acidity, and delays muscle fatigue, thereby improving endurance, strength, and training quality.

Benefits of beta-alanine for athletes:

• Delays muscle fatigue, especially during high-intensity training.
• Improves anaerobic endurance, beneficial for sprints, combat sports, and team sports.
• Reduces lactic acid accumulation, allowing athletes to maintain high intensity longer.

Recommended dosage:

• 2–5 g per day, optimal dose for most is 3.2 g.
• To reduce tingling sensation, divide the dose into 1.6 g portions per day.
• Regular intake is more important than timing, as beta-alanine works through long-term accumulation in the body.

Best methods of intake:

• Consume with carbohydrates and proteins to increase carnosine synthesis.
• Supplements are necessary for athletes, as it is impossible to reach the required beta-alanine level through food alone (meat, poultry, fish).
• Consistent intake is more important than pre-training timing, as the effect depends on long-term saturation.

Beta-alanine is an essential supplement for athletes aiming to increase endurance and reduce muscle fatigue, especially in intense anaerobic activities. When taking beta-alanine, it is important to maintain adequate fluid balance.

Vitamin D in sports

Vitamin D is essential for athletes as it supports bone strength, muscle function, and the immune system. It regulates calcium absorption, reduces the risk of injuries, and contributes to greater muscle strength. Insufficient levels are associated with a higher risk of stress fractures, muscle weakness, and longer recovery times after training.

Athletes who train indoors or live in regions with little sunlight often face vitamin D deficiency. Darker skin pigmentation also reduces its synthesis in the skin, making supplements necessary for some athletes. Natural sources such as fatty fish, egg yolks, and fortified dairy products can help maintain levels but do not always provide enough.

If natural sources are insufficient, the recommended vitamin D3 dose for athletes can range from 15–25 mcg (600–1000 IU) per day. In cases of deficiency, the dose may be higher and adjusted based on blood tests. Regular testing is essential as excessive amounts can cause hypercalcemia, negatively affecting bone and kidney health.

Iron supplements for athletes

Iron is essential for oxygen transport, energy production, and muscle function. Its deficiency can cause fatigue, reduce endurance, and prolong recovery time after training. Athletes, especially women and vegetarians, have a higher risk of iron deficiency due to increased losses through sweat, gastrointestinal micro-tears, and higher inflammation levels.

To prevent deficiency, it is important to consume iron-rich foods such as red meat, liver, lentils, spinach, and beans. Vitamin C improves iron absorption, so it is best combined with citrus fruits, bell peppers, or strawberries. Meanwhile, calcium, coffee, and tea reduce absorption, so their consumption should be separated from iron supplements or iron-containing foods.

Iron supplements are best taken in the morning when hepcidin—the hormone regulating iron absorption—is at its lowest level. Athletes are advised to regularly check ferritin levels in the blood, as excessive supplement intake can cause oxidative stress and damage liver function. Before starting supplements, it is necessary to consult a doctor and individually assess needs.

Can athletes follow a vegetarian or vegan diet and achieve good results?

Yes, athletes can achieve high results by following a vegetarian or vegan diet if a proper balance of nutrients is ensured. Careful meal planning and including complete protein sources (e.g., legumes, soy products, quinoa) can help maintain muscle mass and optimize recovery.

How soon before competitions should new supplement trials be stopped?

New supplement trials should be stopped 4-6 weeks before competitions to allow the athlete to assess their effects, avoid adverse reactions, and ensure optimal preparation.

Do genetic factors affect supplement effectiveness?

Genetic differences can significantly influence supplement effects. Individual genetic profiles determine how the body metabolizes certain nutrients and supplements, so different people may experience different results even when taking the same products.

Should supplement doses be adjusted during different training phases?

Yes, training cycle phases influence supplement use. During intensive training, higher doses may be needed to support energy production and recovery, while off-season periods may involve maintenance doses with reduced supplement amounts.

Which supplements help recovery after injuries?

The main supplements that aid tissue regeneration and reduce inflammation are omega-3 fatty acids, vitamin D, collagen, proteins, and curcumin. They help speed up recovery after injuries, support joint health, and reduce oxidative stress in the body.