Nutrition basics for a tennis player
On normal training and tournament days, nutrition should be balanced. The player needs carbohydrates, protein, healthy fats, vegetables, fruit and enough fluid. Carbohydrates are especially important in tennis because they give quick energy for starts, strokes, long rallies and repeated accelerations. Practical tennis nutrition guidance notes that tennis players need to maintain glycogen stores through enough carbohydrate intake, while protein is needed for recovery after exercise.
Good carbohydrate sources: rice, pasta, buckwheat, potatoes, oatmeal, bread, bananas, fruit and dried fruit.
Protein sources: eggs, chicken, fish, meat, cottage cheese, yogurt, cheese and legumes.
Healthy fats: nuts, avocado, olive oil and fish.
Vegetables and fruit are not there just to make the plate look healthy. They support digestion, vitamins and general health.
Another extreme is dangerous for a young athlete: playing almost without food "to feel lighter". In reality, this often leads to weakness, irritability, loss of concentration and poor recovery.
Vitamins and minerals: what matters for a junior tennis player
Vitamins and minerals do not give quick energy in the same way carbohydrates do, but without them the body recovers worse, tolerates workload worse and may tire faster. Calcium, vitamin D, iron, magnesium, sodium and potassium are especially important for a junior tennis player. For teenagers who train actively, attention to calcium, vitamin D and iron is especially important because of growth, bone load and the risk of deficiency.
Calcium and vitamin D
Calcium is needed for strong bones and teeth, normal muscle work and the nervous system. In tennis this matters because of constant starts, stops, jumps, slides and sharp changes of direction. For children aged 9-13 and teenagers aged 14-18, a reference calcium intake is about 1300 mg per day. Good calcium sources include milk, yogurt, cheese, cottage cheese, kefir, fortified plant drinks, broccoli, cabbage, sardines or salmon with bones.
Vitamin D helps the body absorb calcium. It is also important for muscles, the nervous system and general health. For children and teenagers from 1 to 18 years old, the usual reference is 15 mcg, or 600 IU, per day. Sources of vitamin D include fatty fish, eggs, some dairy products and foods specially fortified with vitamin D. Sunlight also helps the body produce vitamin D, but relying only on sun is not always correct, especially in winter or when the child is rarely outdoors.
Iron
Iron is needed to transport oxygen in the body. If iron is low, the player may tire faster, tolerate long training sessions worse and lose concentration. For teenagers aged 14-18, the iron reference is about 11 mg per day for boys and 15 mg per day for girls. For teenage girls, iron is especially important because of menstruation and growth.
Good iron sources include beef, chicken, turkey, fish, eggs, liver, lentils, beans, chickpeas, buckwheat, spinach, nuts, raisins, fortified cereals and bread. Iron from plant foods is absorbed better when it is eaten with vitamin C foods: orange, berries, kiwi, sweet pepper, tomatoes and broccoli.
Magnesium
Magnesium is involved in muscle and nervous system work, helps the body use energy normally, and supports bones and recovery. For teenagers aged 14-18, a reference intake is about 410 mg per day for boys and 360 mg per day for girls. Sources of magnesium include nuts, seeds, oatmeal, buckwheat, wholegrain bread, beans, lentils, spinach, bananas and yogurt.
It is important not to think of magnesium as a magic solution for all cramps. Cramps can be connected with fatigue, heat, fluid loss, low sodium, overload or poor recovery. So it is better to look at nutrition and drinking overall, instead of looking for one tablet.
Sodium and potassium
Sodium and potassium are electrolytes. They are lost with sweat and help maintain fluid balance. On a normal day, regular food usually provides enough of them. But in heat, during long matches, with heavy sweating or several matches in a day, water alone may not be enough: drinks with electrolytes or food that helps restore salts can be useful. USTA recovery guidance for tennis separately highlights the need to replace fluid and electrolytes, including sodium and potassium, lost through sweat.
Potassium sources include bananas, potatoes, dried fruit, yogurt, beans, lentils and oranges. Sodium sources include normal salty food, soup, salted crackers and sports drinks with electrolytes. On a hot tournament day after a long match, it can sometimes be better to drink not only water, but also a drink with electrolytes.
B vitamins, vitamin C and antioxidants
B vitamins are important for energy metabolism. They do not make the player "faster" by themselves, but they help the body use carbohydrates, protein and fats normally. Sources include grains, wholegrain bread, meat, fish, eggs, dairy products and legumes.
Vitamin C is needed for the immune system, connective tissue and recovery. Sources include citrus fruit, kiwi, berries, sweet pepper, broccoli and tomatoes. Vitamins A and E, and other antioxidants, are better obtained from normal food: vegetables, fruit, berries, greens, nuts and vegetable oils.
Does a junior tennis player need vitamin supplements?
The main rule is: food first, then blood tests, and only then supplements if they are really needed. It is not worth buying "sports vitamins" simply because a child plays tennis. Too much of some substances can also be harmful: for example, very high doses of vitamin D or iron should not be taken without a doctor. NIH directly notes that too much vitamin D can cause health problems, and iron supplements should not be used without need.
A reasonable option for parents: if the child is often tired, recovers poorly, has become pale, gets sick often, complains of weakness or has a sharp drop in endurance, do not start with tablets. Discuss tests with a doctor: complete blood count, ferritin, vitamin D and other markers if a specialist recommends them.
A simple day example
Breakfast: oatmeal + yogurt + banana + berries.
Lunch: rice or pasta + chicken/fish + vegetable salad.
Snack: cottage cheese or yogurt + fruit, or a sandwich with cheese/turkey.
After training: water + food with carbohydrates and protein.
Dinner: potatoes/buckwheat/pasta + eggs/fish/meat + vegetables.
In heat or during a long match: water plus electrolytes, especially if the player sweats a lot.
The conclusion is simple: vitamins and minerals are important, but their role is not to replace normal food. They support growth, health, recovery and stable play. The best diet for a junior tennis player is not tablets, but regular food: grains, meat or fish, eggs, dairy products, vegetables, fruit, legumes, nuts and enough fluid.