Aim: The objective was to describe the strategies that type-1 diabetic runners treated with insulin analogues apply in a half-marathon race and the changes after a year of experience participating in long-distance athletic competitions.
Methods: Fourteen male amateur athletes with type-1 diabetes treated with insulin analogues, participating in two consecutive editions of the same half-marathon were assessed. Data about insulin dosage and carbohydrate intake from their regular daily training and from the two half-marathons were compared. Capillary glycemic values from throughout the competition and in the following 24 h period were monitored and the frequency of hypoglycemia and glucose fluctuations was compared, using MAGE method.
Results: During the half-marathon day, athletes reduced total insulin doses a 18.3% in 2006 and 14.2% in 2007, with a reduction of basal insulin (23.3% in 2006 vs 20.4% in 2007, P<0.05) and of short-insulin at breakfast prior to the competition (31.7% in 2006 vs 15.3% in 2007, P<0.001). Carbohydrate consumption during competition was higher in second edition (49.0±16.4 g vs 59.1±11.2 g, P<0.05). Glycaemic excursions, assessed by MAGE, were higher in the first edition (108.1±47.3 mg/dL vs 62.2±45.6 mg/dL, P<0.05).
Conclusion: Type-1 diabetes athletes, treated with insulin analogues, participating in half-marathon competitions exhibited less insulin reduction in comparison with traditional guidelines and they needed to take an important quantity of carbohydrate supplements to avoid hypoglycemia during and after the competition. We suggest reconsidering traditional recommendations of insulin therapy and carbohydrate supplementation (amount and timing) to athletes treated with current insulin analogues participating in long-distance competitions.