FOOD & WATER: ESSENTIALS FOR THE SWIMMER
NUTRITION: All you need to train and improve your performance can be gained from the right food to eat and fluid replacement.
FOOD: We need to eat to grow and support body turnover, to maintain basic functions, to be able to do physical activity and to supply the nutrients that keep us healthy (vitamins and minerals).
WHAT
FOOD? A balanced intake in the right proportions from ALL nutrient
groups: carbohydrate, protein, fat and vitamins and minerals.
Carbohydrate:
- Bread, pasta, potato, rice & cereal = starches
- Sweets, fruit & sugary snacks = simple sugars
Protein:
Dairy products, eggs, beans, pulses, meat, poultry, fish & nuts
Fat:
Oil, butter, dairy products, meat & nuts
Vitamins & minerals: in all natural food sources
WHEN do we need to eat?
Regularly to avoid feeling hungry as that is when we tend to snack on ‘quick foods’ as we ‘care less’ about what we want to eat, Eating well also gives the mental energy to make better decisions to support an exercise programme and maintain good health.
To do this look at:
- Variety – avoids boredom
- Wholesomeness – least processed as possible
- Moderation - rather than think about good or bad foods (occasional chips and fizzy drink can be ok if balanced with a healthier choice for the rest of the day).
Before Exercise – ALLOW ENOUGH TIME to digest your food. A carbohydrate rich meal 3-4 hours before exercise is recommended. Before competition it is helpful to load up in the 3 days before when also easing back on training.
During exercise – get used to reloading energy during training: carbohydrate containing sports drinks help with this.
After exercise – energy is best replaced within 4 hours. It can take up to 2 days to completely restore energy stores after heavy exercise.
THE IMPORTANCE OF FLUID
‘Loss of fluid and reduction in the body’s carbohydrate stores are the
two major causes of fatigue in prolonged exercise’
Consensus statement – Maughan et al. Br J Sports Med 1993;27:34-5
The body needs to keep its temperature between 37-38’c to work well. Sweating helps control temperature. Sweating amount depends on intensity, length of training as well as temperature and humidity of environment. Most swimming pools are very warm and humid. Sweat contains water and ‘salts’. Water loss of 2% body weight during exercise can affect performance badly. Greater losses can lead to heat stroke or worst death…
IF YOU ARE THIRSTY YOU ARE ALREADY DEHYDRATED!
FIGHT FLUID LOSS
Aim to drink at least 2 litres fluids per day.
Ensure you drink additional fluids BEFORE, DURING & AFTER exercise:
- 200-500mls fluid 2 hours before exercise
- 125-150mls every 15-20 minutes during exercise
- Replace fluids lost during exercise starting immediately by drinking 500mls liquids. Complete rehydration by drinking 150% of body weight lost during exercise (1kg loss = 1.5litres fluid)
ALWAYS CARRY YOUR BOTTLE WITH YOU, DRINK & REFILL FREQUENTLY
WHAT SORT OF DRINKS?
- When you sweat you lose water and salts.
Sports drinks have been designed to reduce dehydration by replacing both the fluids and salts lost during exercise. Water alone will dilute the body’ salts and will switch off your thirst sensation.
Hypotonic drinks replace fluids quickly but have low energy levels.
Isotonic drinks have the same number of particles as blood and so will replace fluid quickly and help maintain energy levels.
Hypertonic drinks can replace energy but as they are stronger than blood concentrations, they can actually make you more dehydrated.
Remember if the climate is hotter or more humid you will need even more fluid replacement then usual. Easy way to check is to look at the colour of your urine; if it is anything other than very pale yellow you need more fluid.
HINTS FOR BEST FOOD AND WATER INTAKE:
1. Introduce changes gradually – never just before competition
2. ALWAYS carry your water bottle; drink regularly through the day; find the RIGHT DRINK for YOU
3. Energy stores need replacing
a. Eat or drink high energy snack straight after training
b. Eat high carbohydrate, low fat meal within 4 hours of training
c. Remember to keep eating, it can take 2 days to restore energy stores
4. Protein is needed for muscle growth and repair; ensure you have enough but go for low fat options where possible.
5. Eat 5 portions of fruit/ vegetables a day as part of a balanced diet to get all the vitamins and minerals you need.
SUPPLEMENTS
Some athletes take supplements, as they believe that they help their performance. They do so at some risk: No guarantee can be given that any supplement, including vitamins and minerals, ergogenic aids or herbal remedies is free from a prohibited substance. Remember that you should be able to get enough vitamins and minerals from a balanced eating plan.
PERSONAL NEEDS
The principles mentioned above are the basis of good nutritional planning but some sportspeople who have chronic diseases, disabilities or those who are going through changes in life i.e. children growing, puberty, pregnancy or advanced age may have slightly special needs. In addition some may need to lose weight, some gain weight. These individuals may need extra advice to support their goals and should seek guidance from a qualified dietician preferably with an interest in sports nutrition.
Further sources of information:
IOC Consensus Statement on Sports Nutrition 2003
www.eis2win.co.uk/gen/wha_sup_nut_01_home.aspx English Institute of Sport
www.disen.org/ This gives the site for Dieticians in Sport & Exercise Nutrition
www.pponline.co.uk/encyc/nutrition.htm
& many more
Dr Harriet Collins
MBBS MRCGP DRCOG DFFP Dip SEM