Why micronutrients matter in sport
Physical activity changes the body's energy and substrate requirements. While macronutrients such as carbohydrates, fats and protein tend to dominate the public discussion, it is the micronutrients – vitamins and minerals – that make many metabolic processes possible in the first place. They act as cofactors in energy production, oxygen transport, muscle contraction and recovery after exertion.
The topic of micronutrients in sport is therefore increasingly discussed by recreational athletes as well. It is important to note: a balanced and varied diet generally covers the need for vitamins for active people. In certain situations – for example with intensive training, a one-sided diet, or a vegetarian or vegan lifestyle – requirements may, however, be increased.
Requirements in active people: what changes
Physical exertion can influence micronutrient balance in several ways:
- Increased consumption due to higher metabolic rates
- Losses through sweat, particularly of minerals such as sodium and magnesium
- Greater need during recovery for repair processes in muscle and connective tissue
- Oxidative stress caused by intensive training, which challenges antioxidative defence systems
How high the individual requirement actually is depends on training volume, type of sport, sex, age and dietary habits. A blanket recommendation is therefore only possible to a limited extent.
Key micronutrients at a glance
Magnesium and recovery
Magnesium is involved in more than 300 enzymatic reactions, including energy provision in muscle cells and muscle contraction. During exercise, some magnesium is lost through sweat. A balanced magnesium status can contribute to normal muscle function and to the reduction of tiredness – aspects often mentioned in the context of magnesium and recovery.
Good sources of magnesium include:
- Wholegrain products and oats
- Nuts and seeds (e.g. pumpkin seeds, almonds)
- Pulses
- Green leafy vegetables
- Mineral water with a high magnesium content
Iron for oxygen transport and endurance
Iron is a central component of the red blood pigment haemoglobin and therefore essential for oxygen transport in the blood. Iron deficiency may manifest as reduced performance, rapid fatigue and difficulties with concentration.
The following groups should pay particular attention:
- Endurance athletes
- Women of childbearing age
- People following a vegetarian or vegan diet
- Adolescents during growth phases
Iron from animal foods (e.g. lean meat, fish) is generally absorbed more efficiently than iron from plant sources such as pulses, wholegrains or green vegetables. Combining intake with vitamin C – for example a glass of orange juice with the meal – can support the absorption of plant-based iron. Supplementation should only take place after medical assessment of iron status.
Vitamin D for muscles and bones
Vitamin D plays a role in calcium and bone metabolism and is also important for muscle function. The body produces vitamin D largely on its own – but only with sufficient sunlight exposure to the skin. In the winter months, endogenous production in Central Europe is markedly limited, which is why lower vitamin D levels are frequently observed during this period.
Vitamin D can only be obtained from the diet to a limited extent, for example via oily fish, eggs or fortified foods. Supplementation can be useful but ideally should be based on measurement of blood levels and discussed with a doctor.
B vitamins for energy metabolism
The B vitamin group (B1, B2, B6, B12, folic acid and others) is closely linked to energy metabolism and the formation of red blood cells. Vitamin B12 occurs almost exclusively in animal foods – athletes following a vegan lifestyle should have their status checked regularly.
Zinc, selenium and antioxidative vitamins
- Zinc is involved in immune function, wound healing and protein metabolism.
- Selenium contributes to the antioxidative defence system.
- Vitamin C and vitamin E support the protection of cells against oxidative stress.
A moderate intake of varied foods generally covers these micronutrients well. Very high doses from dietary supplements are not automatically performance-enhancing and may in individual cases even be disadvantageous.
Electrolytes: sodium, potassium, calcium
During long or intense exercise, especially in the heat, electrolytes are lost through sweat. An appropriate intake of fluids and electrolytes supports normal muscle function and fluid balance.
Dietary supplements: useful or unnecessary?
Dietary supplements are not a substitute for a balanced diet. Before reaching for products, it is worth taking a critical look at the daily menu. Targeted supplementation can be sensible:
- in cases of a documented deficiency
- in particular life situations (pregnancy, vegan diet)
- with very high training loads
- following medical recommendation based on a blood test
Uncritical use of high-dose preparations can have the opposite of the intended effect. Interactions with medication are also possible.
Practical recommendations for active people
- Aim for a varied diet with vegetables, fruit, wholegrains, pulses, nuts, high-quality protein sources and healthy fats
- Drink enough – water or unsweetened beverages; during longer exertion, possibly with electrolytes
- Plan meals around training times to support energy and nutrient supply
- Have persistent fatigue, decline in performance or other symptoms medically assessed
- Have individual requirements checked before starting supplementation
Conclusion
Micronutrients are an important but often underestimated element in the interplay of nutrition, training and recovery. Magnesium, iron and vitamin D are among the most frequently discussed substances, but B vitamins, zinc, selenium and electrolytes also deserve attention. A balanced diet forms the basis; targeted supplementation should be based on an individual assessment – ideally after medical advice and laboratory testing.
This article does not replace medical advice.