diet and nutrition

Answer: Energy balance is the relationship between calories consumed (energy in from food and drink) and calories expended (energy out from BMR, physical activity and digestion). When energy in equals energy out, body weight is maintained. When energy in exceeds energy out, the excess is stored as fat and weight is gained. When energy out exceeds energy in, the body uses stored fat for energy and weight is lost. Athletes must manage energy balance carefully to maintain optimal body composition for their sport.

Answer: Energy balance is the relationship between calories consumed (energy in from food and drink) and calories expended (energy out from BMR, physical activity and digestion). When energy in equals energy out, body weight is maintained. When energy in exceeds energy out, the excess is stored as fat and weight is gained. When energy out exceeds energy in, the body uses stored fat for energy and weight is lost. Athletes must manage energy balance carefully to maintain optimal body composition for their sport.

Answer: Carbohydrates are the body's primary and most efficient energy source, particularly for high-intensity exercise. They are broken down into glucose and stored as glycogen in muscles and the liver. During exercise, glycogen is converted back to glucose and used for energy through glycolysis. Complex carbohydrates are preferred in pre-event meals because they provide slow, sustained energy release over a longer period, maintaining blood glucose levels throughout the event. Simple carbohydrates provide quick-release energy that may cause a blood sugar spike followed by a crash, which is not ideal for sustained performance.

Answer: Iron is essential for athletes because it is the core component of haemoglobin, the protein in red blood cells that transports oxygen from the lungs to working muscles. Without sufficient iron, oxygen transport is impaired, reducing aerobic capacity and causing fatigue (anaemia). This is especially important for endurance athletes and female athletes who lose iron through menstruation. Calcium is important for athletes because it is essential for bone formation and strength, reducing the risk of stress fractures. Calcium is also required for muscle contraction and blood clotting. Athletes in weight-bearing sports and those with low body weight (which can affect bone density) particularly need adequate calcium.

Answer: Pre-event (2-4 hours before): A meal high in complex carbohydrates (e.g. pasta with tomato sauce) for sustained energy, with moderate protein and low fat/fibre for easy digestion. Pre-event (30 min before): Simple carbohydrate snack (e.g. banana) for quick energy. During the marathon: Sports drinks containing carbohydrates and electrolytes to maintain blood glucose and hydration; energy gels for additional carbohydrate intake (30-60g carbs per hour). Post-event (within 30-60 minutes): A combination of protein and carbohydrates (e.g. chocolate milk or protein shake with banana) for muscle repair and glycogen replenishment, plus water for rehydration.

Answer: Athletes should avoid high-fibre foods before competition because fibre is indigestible and can cause bloating, gas, stomach cramps and diarrhoea during exercise. These gastrointestinal issues are uncomfortable and distracting, and can significantly impair performance. Fibre also slows gastric emptying, meaning food stays in the stomach longer rather than being absorbed for energy. In the 24-48 hours before competition, athletes should reduce fibre intake and focus on easily digestible, low-fibre carbohydrate sources like white rice, white pasta and refined cereals.

Answer: Protein is essential for post-exercise recovery because intense training causes micro-tears in muscle fibres, and protein provides the amino acids needed to repair this damage and rebuild stronger muscle tissue (hypertrophy). The 30-60 minute window after exercise is when muscles are most receptive to protein uptake, making it the optimal time for protein consumption. For a strength athlete, an appropriate post-event meal would be grilled chicken breast with rice and vegetables, or a protein shake with a banana. The chicken/protein shake provides high-quality protein for muscle repair, while the rice/banana provides carbohydrates to replenish glycogen stores. The 3:1 carbohydrate-to-protein ratio supports both recovery goals.