Nutrition For Young Swimmers (Aged 11 - 18)
Good nutrition is an essential part of swim training. Eating the right foods - in the right amounts and at the right times - helps swimmers train harder, recover faster, and stay healthy throughout the season.
For parents and coaches, supporting good eating habits is as important as supporting good technique. Young swimmers are growing fast and training hard, often for hours a day, so their bodies need plenty of fuel to perform, recover and develop properly.
The energy demands of swim training
Competitive swimmers often train two to four hours a day, sometimes in double sessions. Add school, growth and recovery, and energy needs can be double those of less active teenagers.
Energy from food powers:
Training and competition
Growth and development (bones, muscles, hormones)
Recovery and adaptation
Concentration and learning
Immune function
When swimmers don’t eat enough to meet these demands, the body starts to conserve energy. Growth may slow, fatigue can set in, and performance often declines. This is known as low energy availability (LEA) and, if it continues, can lead to Relative Energy Deficiency in Sport (RED-S), a condition that affects both health and performance.
Why fuelling properly matters
Under-fuelling can happen easily - skipping breakfast, eating too little after training, or cutting down on carbohydrates. Even small energy gaps, repeated over time, can lead to problems.
Warning signs of RED-S or low energy availability include:
Persistent tiredness or lack of energy during training
Declining performance despite consistent effort
Frequent illness or injury
Difficulty sleeping
Mood changes, irritability or low motivation
Missed or irregular periods in girls
Stalled growth or muscle loss
If these occur, it’s important to seek advice from a doctor or registered sports nutritionist.
Eating enough, and eating regularly, helps swimmers stay strong, recover faster and maintain health. Fuel is your friend, not your enemy.
Building a healthy swimmer’s plate
A balanced diet provides carbohydrates for energy, protein for growth and repair, healthy fats for hormone and heart health, and a variety of vitamins and minerals for overall wellbeing.
A simple way to build meals is to divide the plate into thirds:
⅓ carbohydrates – pasta, rice, bread, potatoes, oats, cereals
⅓ protein – chicken, fish, eggs, lean meat, tofu, beans or lentils
⅓ vegetables or salad
Add healthy fats such as olive oil, nuts, seeds, avocado or oily fish, and aim for at least five portions of fruit and vegetables each day.
On heavy training days, slightly increase the carbohydrate portion to match the extra energy demand.
Before early morning training
Many swimmers train early, when appetite is low. But swimming on an empty stomach can lead to low blood sugar, early fatigue and poor concentration.
A small, high-carbohydrate snack before training provides valuable fuel. Suitable options include:
Toast with honey or jam
A banana or other fruit
A cereal or fruit bar (e.g. Nakd, Eat Natural)
Porridge made with milk or a milk alternative
A smoothie made with fruit and milk
If solid food isn’t appealing, a drink that provides energy, such as a fruit smoothie or diluted fruit juice, is a good alternative. It also helps to have a glass of water before leaving home to rehydrate after sleep.
After morning training
After training, muscles need carbohydrate and protein to refuel and repair. Aim to eat within 30–60 minutes of finishing your session.
Good post-swim breakfasts include:
Porridge made with milk, topped with banana, berries and a handful of nuts or seeds
Wholegrain toast or bagel with eggs, plus fruit on the side
Greek yogurt with granola and fruit
Smoothie made with milk, oats and fruit
Wholegrain cereal with milk and sliced banana
These meals replace energy stores, support muscle recovery and prepare you for the day ahead.
Eating through the day
Regular eating helps swimmers maintain energy and concentration. Skipping meals leads to tiredness, poor focus and reduced training quality.
A good pattern is three main meals and two to four snacks each day.
Snacks for school or between sessions might include:
Fresh or dried fruit
Yogurt or milk drink
Sandwich, wrap or roll
Nuts, seeds or a cereal bar
Crackers with cheese or peanut butter
Eating consistently throughout the day supports steady energy levels and healthy growth.
Fuel before evening training
The main pre-training meal should be eaten two to three hours before swimming, giving enough time for digestion.
If training starts at 7 pm, eat around 4–5 pm; if earlier, have a lighter meal or snack at 3–4 pm.
Good pre-training meals include:
Pasta with tomato sauce and chicken, fish or tofu
Rice with beans, salmon or lean meat plus vegetables
Jacket potato with tuna, cheese or beans
If time is short, a smaller snack 30–60 minutes before training will help maintain energy:
Toast with jam
Banana and yogurt
Dried fruit and nuts
Cereal with milk
During training: stay hydrated
Even in the pool, swimmers sweat and lose fluid. Dehydration makes training feel harder and reduces performance.
To stay hydrated:
Begin sessions well hydrated - urine should be pale yellow
Sip small amounts regularly (around 125–200 ml every 15–20 minutes)
For long or intense sessions, use a diluted squash (1:6 ratio) or light sports drink to replace both fluid and carbohydrate
After training, rehydrate with water, milk or a recovery drink
Recovery after training: the 4 Rs
Recovery is when the body adapts to training - muscles repair, energy stores refill and strength improves. Because sessions are often just hours apart, effective recovery is crucial for young swimmers.
Think of the 4 Rs:
1. Refuel – replace energy stores
Carbohydrate is the body’s main training fuel. Replenish glycogen as soon as possible - ideally within 30 minutes of finishing.
Aim for about 1 g carbohydrate per kg body weight (e.g. 50 g for a 50 kg swimmer).
Easy options include banana and yogurt, a smoothie, porridge, or a sandwich.
2. Repair – rebuild muscles
Protein supports recovery and growth.
Aim for about 0.3 g protein per kg body weight (15–25 g for most teens).
Good sources include milk, yogurt, eggs, chicken, fish, tofu, beans or lentils.
Spread protein evenly across meals and snacks for best results.
3. Rehydrate – replace fluids and electrolytes
Even in the pool, fluid losses can be significant.
Replace around 1.5 litres of fluid for every kilogram of body weight lost during training.
Milk or flavoured milk are ideal as they provide fluid, electrolytes, carbohydrate and protein together.
4. Rest – allow time to adapt
Nutrition jump-starts recovery, but rest and sleep complete it.
Aim for 8–10 hours of sleep each night
Short naps or quiet breaks between sessions also help
Good recovery options:
500 ml milk, chocolate milk or milkshake
Smoothie with milk or yogurt, fruit and oats
Greek yogurt with berries and granola
Wholegrain toast or sandwich with peanut butter, cheese or chicken
Then, have a balanced meal — including carbohydrates, protein and vegetables — once you get home.
Supporting growth and long-term health
Swimmers aged 11–18 are still growing, so nutrition must support both performance and development. Under-eating can affect growth, bone health and hormones.
Parents and coaches should encourage balanced, consistent eating rather than restriction. Emphasise wellbeing and performance, not weight.
Iron is especially important for teenage girls. Include lean red meat, beans, lentils, leafy greens and fortified cereals, and pair them with vitamin C-rich foods to boost absorption.
Supplements are rarely needed if the diet is varied and balanced. If used, always choose Informed-Sport certified products.
Key take-home tips
Fuel every session – carbohydrates are your main energy source
Eat regularly – three meals and snacks to meet daily energy needs
Recover smart – carbs, protein, fluids and rest after each session
Stay hydrated – before, during and after swimming
Watch for warning signs – fatigue, poor recovery or missed periods can signal under-fuelling
Focus on performance, not restriction – your body needs fuel to swim fast and grow strong