Nutrition in Exercise and Sports

Proper nutrition is the cornerstone of athletic performance, recovery, and longterm health. Whether you are a recreational jogger, a competitive swimmer, or a strengthtraining enthusiast, the food you take in fuels your training, supports muscle repair, and helps you stay hydrated. This page outlines the key concepts of sports nutrition, including energy requirements, macronutrient balance, essential micronutrients, hydration strategies, timing of meals, and evidencebased supplements.

Energy Needs

Energy is measured in calories (kilocalories) and comes from the oxidation of carbohydrates, fats, and proteins. An athletes total daily energy expenditure (TDEE) consists of basal metabolic rate, the thermic effect of food, and the energy cost of training. Rough guidelines are:

• Endurance athletes: 4560kcalkgday
• Strength/power athletes: 3545kcalkgday
• Highly active youth and adolescents: 5070kcalkgday

Matching energy intake to expenditure prevents unwanted weight loss, preserves lean body mass, and reduces the risk of fatigue, injury, and impaired immune function.

Macronutrients

Carbohydrates

Carbohydrates are the primary fuel for highintensity activities. Muscle glycogen stores provide energy for bouts lasting up to 2hours. Recommendations:

• Endurance training: 57gkgday (moderate volume)
• Heavy training or competition: 710gkgday
• Ultraendurance: 1012gkgday

Choose complex carbs (whole grains, legumes, fruits) for daily meals and simple carbs (fruit juice, sports gels) around workouts for rapid absorption.

Proteins

Protein supports muscle repair, adaptation, and immune health. Athletes need more than the general recommendation of 0.8gkgday. Suggested intakes:

• Endurance athletes: 1.21.4gkgday
• Strength/power athletes: 1.62.2gkgday
• Older athletes: 1.21.5gkgday (to counteract sarcopenia)

Spread protein intake over 34 meals, aiming for 0.250.35gkg per serving. Highquality sources include lean meats, dairy, eggs, soy, and legumes.

Fats

Dietary fat provides essential fatty acids and is the main fuel during lowintensity, longduration exercise. Fat should comprise 2035% of total calories. Emphasize unsaturated fats:

• Omega3 rich fish (salmon, mackerel)
• Olive oil, avocado, nuts, and seeds

Limit saturated fat (<10% of calories) and avoid trans fats.

Micronutrients

Vitamins and minerals are vital for energy metabolism, oxygen transport, and muscle contraction. Deficiencies can impair performance and recovery.

Most athletes meet their micronutrient needs through a varied diet. However, vegetarian/vegan athletes may need extra B12, iron, zinc, and omega3 DHA/EPA from fortified foods or supplements.

Hydration

Dehydration of as little as 2% body mass can reduce endurance performance, increase perceived effort, and impair thermoregulation. Hydration strategy:

1. Preexercise: Drink 510mlkg of water 23h before activity.
2. During exercise: Aim for 150250ml15min, adjusting for climate and sweat rate.
3. Postexercise: Replace 1.5L of fluid for every kilogram of body weight lost (weigh before and after).

For sessions longer than 60minutes, include a carbohydrateelectrolyte solution (68% carbohydrate, 0.5% sodium) to maintain blood glucose and electrolyte balance.

Nutrient Timing

When you eat can be as important as what you eat. Three critical windows are highlighted below.

1. PreExercise (34h)

A meal containing 14gkg of carbohydrate and 1525g of protein supports glycogen stores and provides amino acids for muscle protection. Example: oatmeal with banana, whey protein, and a handful of nuts.

2. During Exercise

For efforts >90minutes, ingest 3060g of carbohydrate per hour (e.g., sports drinks, gels, or fruit). Keep fluids steady, as described in the hydration section.

3. PostExercise (02h)

The anabolic window is a period of heightened insulin sensitivity. Aim for a 3:1 or 4:1 carbohydratetoprotein ratio, delivering about 0.50.7gkg of carbohydrate and 0.20.3gkg of protein. Chocolate milk, a turkey sandwich with fruit, or a recovery shake are effective options.

EvidenceBased Supplements

Supplements can fill gaps but should never replace a balanced diet. Below are the most researched ergogenic aids:

• Creatine monohydrate 35g daily improves highintensity repeatedsprint performance and increases lean mass.
• Caffeine 36mgkg taken 3060min before exercise enhances endurance, focus, and perceived effort.
• Betaalanine 25g daily (split doses) buffers acid in muscles, beneficial for events lasting 14minutes.
• Omega3 fatty acids (EPA/DHA) 12g daily may aid recovery and reduce inflammation.
• Vitamin D 10002000IU daily for athletes with low serum levels improves bone health and immune function.

Avoid highdose multivitamins, proprietary fat burners, or products with undisclosed ingredients. Always check for thirdparty testing (e.g., NSF, InformedSport) and consult a sports dietitian or physician before starting any supplement regimen.

Practical Tips for Everyday Use

• Plan meals around training sessions; keep a food diary for the first two weeks.
• Choose whole, minimally processed foods for most meals; reserve sports gels and drinks for training/competition.
• Carry a portable snack (e.g., trail mix, a banana, or a protein bar) for unexpected long sessions.
• Monitor body weight and urine color to gauge hydration.
• Adjust portions seasonally or when training volume changes.
• Prioritize sleep and stress managementboth affect nutrient utilization.