Nutrition for Sport & Exercise Performance

Introduction

Performance on the field, track or gym is not just a product of training; it is also profoundly influenced by what you eat and drink. Proper nutrition supplies the fuel for movement, supports recovery, and helps prevent injuries. This page outlines the key principles athletes and active people should follow to optimise performance.

Energy Needs

Energy is measured in calories (kilocalories, kcal). The amount required varies with the sports intensity, duration, and the athletes body size. In general:

• Endurance athletes (e.g., marathoners, cyclists) need 4570 kcalkgday.
• Strength/power athletes (e.g., weightlifters, sprinters) need 3550 kcalkgday.
• Recreationally active individuals generally need 3035 kcalkgday.

Failing to meet energy demands can lead to relative energy deficiency in sport (REDS), which impairs hormone balance, bone health and immune function.

Macronutrients

Carbohydrates

Carbs are the primary fuel for highintensity work. Recommended intake:

Focus on complex sources (whole grains, potatoes, legumes) and include some simple carbs (fruit, honey) around training for quick energy.

Proteins

Protein supports muscle repair, adaptation and immune health. Recommendations:

• Endurance athletes: 1.21.4gkgday
• Strength/power athletes: 1.62.2gkgday
• General active adults: 0.81.0gkgday

Highquality sources include lean meat, fish, eggs, dairy, soy, and legumes. Distribute protein evenly across meals (0.25gkg per serving) to maximise muscle protein synthesis.

Fats

Dietary fat is essential for hormone production, vitamin absorption and as a lowintensity fuel source. Aim for 2035% of total calories, emphasizing:

• Monounsaturated fats olive oil, avocado, nuts.
• Polyunsaturated fats fatty fish (EPA/DHA), flaxseed, walnuts.
• Limit saturated fat to <10% and avoid transfats.

Micronutrients

Vitamins and minerals are required in smaller amounts but are critical for energy metabolism, oxygen transport and muscle contraction.

Iron

Especially important for females and endurance athletes. Sources: red meat, fortified cereals, legumes, spinach. Pair plant sources with vitaminC to improve absorption.

Calcium & VitaminD

Key for bone health and muscle function. Sources: dairy, fortified plant milks, fortified orange juice, sunlight exposure for vitaminD.

Electrolytes (Sodium, Potassium, Magnesium)

Lost in sweat, they maintain fluid balance and nerve transmission. Replace through sports drinks, salty foods, bananas, nuts and leafy greens during prolonged sessions.

Antioxidants (VitaminC, VitaminE, Selenium)

Help counteract oxidative stress from intense training. Obtain from colorful fruits, nuts, seeds and whole grains.

Hydration

Even a 2% loss of body mass from sweat can impair performance. Guidelines:

1. Weigh yourself before and after a typical training session. Each kilogram lost 1L of fluid needed.
2. Drink 500mL of water 23hours before exercise.
3. During activity, aim for 150250mL every 1520minutes. For sessions >1hour, include a sports drink with 68% carbohydrate and 200400mg sodium.
4. Postexercise, replace 150% of the fluid lost within 4hours.

Monitor urine color (pale yellow is ideal) and thirst as simple cues.

Meal Timing & Composition

PreExercise

Eat a carbohydraterich meal 34hours before activity (e.g., oatmeal with fruit and yogurt). If training starts within 1hour, a small snack (banana, toast with jam) provides quick glucose without GI distress.

During Exercise

For efforts lasting longer than 60minutes, consume 3060g of carbohydrate per hour. Options: sports gels, dried fruit, lowfat granola bars, or diluted juice.

PostExercise

The anabolic window is roughly 3060minutes after training. Aim for a 3:1 or 4:1 carbohydratetoprotein ratio (e.g., chocolate milk, recovery shake, turkey sandwich with fruit). This replenishes glycogen and stimulates muscle repair.

EvidenceBased Supplements

Supplements can be helpful when dietary intake is insufficient, but they should never replace a balanced diet.

Always check for thirdparty testing (e.g., NSF Certified for Sport) to avoid contaminants.

Practical Tips for Everyday Athletes

• Plan meals ahead of training days to avoid lastminute junk food.
• Keep a food and fluid log for a week to identify gaps.
• Use colorcoded plates: half vegetables/fruits, a quarter protein, a quarter carbs.
• Carry portable snacks (nuts, energy bars) for travel or early morning sessions.
• Prioritise sleep (79h) because recovery processes are largely nocturnal.
• Adjust intake on rest daysslightly lower carbs but maintain protein and healthy fats.