Increase your carbohydrates
The healthy balanced diet recommended for people with diabetes is also the diet recommended for athletes. However, you will probably find that you need to increase your portions of starchy carbohydrate foods at all meals and snacks during the training period, as well as reducing your insulin dose.
Eating plenty of starchy carbohydrate foods not only helps prevent hypos, it also helps replenish stores of energy in the muscles after each training session. Research suggests that eating a combination of protein and carbohydrate increases the uptake of muscle glycogen, while food eaten within two hours of activity promotes maximum intake into the muscles and liver. Muscles that are well nourished are less prone to injury and more responsive to training, so it is worth adjusting your eating times to fit in with your next training session.
During any training session lasting more than one hour it is important to take more carbohydrate and fluids. Fluids which also contain carbohydrate are useful, eg fruit juice and squash, or isotonic sports drinks. During a long or strenuous ride, eat more carbohydrate snacks, such as sports bars, cereal bars, chocolate or bananas.
If you have been swimming
You may feel hungrier afterwards than you would do had you done some other kind of sport. This is because of the extra calorific effort involved in maintaining body temperature, whilst also using calories to produce energy. Having a carbohydrate snack straight after swimming can begin the resynthesis of muscle glycogen that is necessary to keep you in good condition.
Drink
Drink plenty of water during and after the training session. Thirst is a sign of dehydration. Drink small amounts frequently, even if you are not thirsty – approximately 150ml of fluid every 15 minutes - because dehydration dramatically affects performance.
Isotonic sports drinks
Isotonic sports drinks, eg Lucozade Sport or Boots Isotonic, describe a wide range of products that usually contain water, sugar, and electrolytes and, typically, 5-8 g carbohydrate per 100 ml.
Isotonic sports drinks contain quickly absorbed carbohydrates which can help to give the blood glucose level a boost during strenuous exercise. Sports drinks do not cause delayed stomach emptying or stomach cramps and can be used before and during a race.
This is in contrast to drinks with more than 8g of carbohydrate per 100 mls, which can cause stomach cramps and slow down fluid absorption due to their effects of delaying stomach emptying. These drinks, eg Red Bull, Purdeys, Lipovitan,B3 and Power House, are not recommended.