Regular exercise is known to be beneficial for people with diabetes, but can make glycemic control challenging. This balance is even more difficult to achieve in adolescents, as insulin requirements are influenced by fluctuating nutritional intake, physical activity levels, and the rhythms of other anti-insulin hormones. Adding to the confusion is that the symptoms of low or high blood glucose are often masked by exercise, because they're so similar: increased heart rate, sweating, shakiness, fatigue and dehydration.

"Any obvious issues with performance - poor passing, failed free throws and serves - that are really out of the ordinary should be a warning sign to check blood glucose levels and add carbohydrates," Riddell says. The best way to boost blood sugar levels is to consume about 15-30 grams of a fast-acting carbohydrate, such as dextrose tablets, juice or a sports drink. "These are rapidly absorbed and immediately replenish the very small reserve of glucose normally found in the blood stream," he says.

Incidents of moderate to severe hypoglycemia were common on the evenings following sports camp participation. However, researchers found no evidence that a bout of nocturnal hypoglycemia influences sport skill performance the following day. Cognitive testing also showed that participants' reading ability was lower during episodes of hypoglycemia, as was the ability to distinguish and name colours.

Riddell notes the importance of conducting this type of field research, as opposed to lab-based studies. "Actually playing a sport involves different cognitive processing, reaction time and motor skill performance," he says.

Source: York University