Type 1 diabetes & heavy physical activity

If you are engaged in heavy physical activity for an entire day, you may need to lower your insulin doses considerably (often by 20% and sometimes even by 50%). You will need extra energy, glucose and fluid at regular intervals (approximately 40 g carbohydrate per hour). When you are involved in prolonged physical work (many hours) it is best to try to increase the time of activity gradually, i.e. by 1-2 hours each day. You will probably need to lower your basal insulin considerably. You may need short-acting or rapid-acting insulin more frequently (every second to fourth hour) together with extra energy in the form of quick carbohydrates. Check your blood glucose and ketones (in blood or urine) regularly during the exercise. There is a risk of ketoacidosis because of an insufficient intake of carbohydrates in combination with low glycogen stores in the liver and too great a reduction of insulin doses. Ideally, ketones should be monitored also during the recovery phase.