A balanced diet
- Carbohydrates: the main energy source, especially for high-intensity exercise. Found in pasta, rice, bread and potatoes.
- Fats: energy for low-intensity, long-duration exercise, and insulation. Found in butter, oil and nuts.
- Protein: growth and repair of muscle. Found in meat, fish, eggs, beans and pulses.
- Vitamins and minerals: help the body work properly, such as calcium for bones and iron for red blood cells.
- Fibre: helps digestion. Water: keeps the body hydrated.
Energy balance
- The average adult man needs about 2,500 kcal a day and the average adult woman about 2,000 kcal a day.
- Energy needs depend on age, gender, height and how active a person is.
- If energy in (food) is more than energy out (activity), weight goes up; if it is less, weight goes down.
Diet for sport
- Carbohydrate loading before an endurance event fills glycogen stores.
- Protein helps muscles repair and grow, so power athletes may eat more of it.
- Timing matters: eat a light meal a few hours before exercise, and refuel afterwards.
Hydration
- Water balance means drinking enough to replace fluid lost in sweat and urine.
- Dehydration thickens the blood, raises heart rate, causes overheating, slows reaction time, and can cause muscle cramps and nausea.
- Drink before, during and after exercise, especially in hot weather.
Key terms
- Balanced diet
- Eating the right amounts of each nutrient for your needs.
- Carbohydrate
- A nutrient that is the main source of energy.
- Protein
- A nutrient for the growth and repair of muscles.
- Fibre
- A nutrient that helps digestion.
- Carbohydrate loading
- Eating extra carbohydrates before an endurance event.
- Dehydration
- Too little water in the body.
- Energy balance
- When energy taken in equals energy used.
- Hydration
- Having enough water in the body.