|Control of type I diabetes during an Ironman triathlon
Boehncke S, Kazda Ch, Poettgen K, Reusch J, Badenhoop K
Intensive insulin therapy and insulin pump improve control of type I diabetes. Therefore patients may approach extreme athletic challenges characterized by maximum demands on glucose metabolism and fluid balance.
10 athletes with type I diabetes were monitored on the occasion of the Ironman Germany triathlon. A standardized questionnaire was completed. Additionally, blood glucose levels and carbohydrate intake were documented.
A complete data set was obtained from 6 triathletes (age 32-61). In 3/6 diabetes was diagnosed 2-7 years ago, whereas the other 3 had diabetes for >25 years. A1C ranged from 5.1 to 7.2%. Current therapy consisted of intensive therapy ( 3/6 injections, 3/6 insulin pump).
9/10 athletes finished in times ranging from 10:45 to 14:53h, matching the results of the field in total. Average fluid intake was around 1 l/h, consisting of water and isotonic drinks along with caffeine- and taurin-containing drinks during the marathon. Total fluid uptake on race day was around 13l. Nutrition included gels, power bars, bananas, and salty biscuits. 24-48 g carbohydrates were consumed per hour, primarily in the form of fast-resorbing carbohydrates. Total uptake during race day was around 540g carbohydrates. Reduction of basal insulin delivery in the insulin pump treated patients was 30-50%, for basal insulin up to 70%.
6/6 athletes encountered hypoglycemia, all occurring during the marathon. 3 finishers received infusions in the finish area because of clinical signs of dehydration. Additional problems included abdominal discomfort (n=5) and muscle cramps during biking (n=2).
Race results of the athletes with diabetes included in this study match those of the total field, thus documenting their ability to succeed in extreme endurance competitions in a way comparable to non-diabetic athletes. This is largely due to optimization of therapy along with adequate training. Documentation of the above-mentioned experiences is of importance not only for medical guidance of athletes with diabetes, but also to convince diabetologists that extreme sports can be performed by athletes with diabetes as successful as by non-diabetic athletes.