The Diabetic Runner, Part 2: Carb Quantity & Timing

In the Diabetic Runner, part 1 we reviewed the importance of maintaining a diary that measures blood glucose response based on food, fluid, activity and medication. It was identified that many diabetics feel most comfortable when their blood glucose ranges from 120 mg/dL – 180 mg/dL. Part 2 of our diabetic runner discussion reviews how much carbohydrate an individual needs to consume while exercising to maintain an optimal blood sugar level. During activity, the diabetic athlete should consume 15 – 30 grams of carbohydrate for every 30-60 minutes of moderate exercise or approximately 0.5 grams of carbohydrate/pound/hour of body weight for more intensive exercise. If moderate exercise is planned to last for more than 90 minutes, or strenuous exercise lasting 60 minutes, the athlete may need to consume extra carbohydrates (~75-100 grams/hour). See your physician for rules on adjusting medication.


Some athletes experience “Big Game” induced hyperglycemia (high blood sugar) that may be related to anxiety. Mental relaxation techniques and race experience may reduce this stress response. Athletes should always carry fast acting carbohydrates such as a premeasured amount of sports drink, glucose gels or tabs, SweetTarts, Sprees or Smarties and ketone test strips.

These tips are not meant to be a substitution or replacement for diabetic management prescribed by your health care practitioner. Diabetic athletes with questions are encouraged to follow up with their physician and a Registered Dietitian knowledgeable in sports and diabetes nutrition. Source: Nancy Clark, MS RD, CSSD Sports Nutrition Guidebook, Jackie Berning, PHD, RD, CSSD, Michael McDermott, PhD, RD, CSSD and Roberta Anding, RD, CDE, CSSD Advanced Strategies for Counseling Athletes with Type 1 Diabetes, SCAN’s Pulse Spring 2010.