Good nutrition is essential for performance. The food you eat fuels exercise and getting the right balance can help give you the upper hand. Both athletes and non-athletes need the same nutrients…but they need to consume them in different quantities and proportions.
Carbohydrates are the sugars present in sugars, cereal grains, fruits and vegetables and they are the preferred source of fuel for working muscles. Your body must break down carbohydrates in order to turn them into glucose (blood sugar). Inadequate carbohydrate intake will result in tiredness and impaired performance. A marathon runner’s diet needs to be carbohydrate rich and carbohydrates should make up 60-70% of their total calorie intake. Wholegrains, pasta, rice, potatoes and oats are the best choices and will provide powerful fuel for muscles and help restocking of muscle fuel after exercise.
How much carbohydrate do I need? To find how much carbohydrate you need to consume daily multiply your weight in kg by 7. That will tell you how many grams of carbohydrate you need daily.
The glycaemic index (GI) refers to how quickly a carbohydrate food is converted to sugar in the blood after consumption. Low GI carbohydrates like oats, pasta and wholegrain give a slow release of energy and are the best choices at a mealtime. Whereas high GI carbohydrates, like biscuits, jellies, sports drinks, rapidly boost blood sugar levels and are the best choices immediately after training.
Although vitamins and minerals do not provide any energy, there are essential in helping the body breakdown proteins and carbohydrates and help you perform efficiently and effectively. Eating a varied balanced diet including lots of fruit and vegetables will ensure that you meet your requirements. If you do choose to take vitamin supplements avoid very high doses.
Fluid is critical for performance and dehydration can lead to tiredness, impaired performance and cramps. Prehydration is just as important as rehydration so drink lots on the days you are not working out too. Sports drinks are generally recommended for a work out of longer than one hour.
Fluid guidelines…Aim to drink 500 mls about 15-20 minutes before exercise. Sip 120-150 mils every 15-20 minutes during exercise and drink 500 mls or more afterwards. During hot weather you may need to drink more
To check you are drinking enough…Weigh yourself undressed before and after exercise. Try to keep weight loss below 0.5 kg by increasing fluid intake during exercise. After exercise you must drink 1.5 litres of fluid for each kg of weight lost.
Protein; a good protein intake is important for any marathon runner, approximately 15-20 % of overall calorie intake. Protein is necessary for growth, maintenance, and repair of body tissue. The best sources of protein include lean meat, poultry, fish, pulses, nuts, seeds, eggs and low fat cheese. Vegetarians need to rake extra are to ensure they are meeting their protein requirements. Always have a protein rich food at 2 or more meals per day. To work out how grams of protein you need daily when training for a marathon multiply your weight in kg by 1.3