Thanks to various studies and much intense research, the past decade has seen a remarkable increase in the scientific understanding of diabetes and exercise. This has enabled diabetic athletes of all abilities to perform to their own highest levels. Training for and completing the Cape Town Cycle Tour is no different – it comes down to clever nutrition management.
“To best control glucose levels, athletes with diabetes can typically follow the nutritional guidelines for non-diabetic athletes because the type of fuel and the way fuel is converted into energy in the muscles is very much the same,” explains Leanne Kiezer, a registered dietitian affiliated with Pick n Pay.
According to Kiezer, it is however crucial that the diabetic athlete is more particular about the type, amount and timing of carbohydrate intake around exercise. “Experimenting and establishing nutrition strategies during training sessions is important so that blood glucose (sugar) levels can be best managed on race day,” she says.
Keizer outlines a few tips around these nutrition strategies:
1. Insulin
Exercise enhances insulin sensitivity, which means diabetic athletes on insulin will need to adjust their insulin regime when exercising. Regular blood-glucose monitoring is important to fine-tune these adjustments.
- Pre-exercise insulin will need to be adjusted for exercise lasting longer than 30 minutes. The longer the exercise session, the less insulin is needed.
- It is important to be aware of the insulin’s peak period and to avoid this coinciding with exercise to avoid hypoglycaemia.
- The absorption of insulin in exercising muscles is increased. Injecting into the abdomen (rather than leg or arm) before exercise may result in better control.
- Try to time your meals and snacks around exercise to avoid having to give large doses of insulin too close to exercise.
2. Controlling blood-glucose levels during competition
Blood-glucose levels should be closely monitored on race day (as during any important event) as they can be affected by the hormones released from excitement and nerves. Be sure not to reduce carbohydrate intake or reduce insulin dosage too much as this can negatively impact performance. Forward planning, experience and relaxation techniques can help in managing these effects.
3. Carbohydrate intake around exercise
Your pre-training or race meal should be eaten one to three hours before the start, with the support of an additional 15g of carbohydrate from a high GI food taken just before. The recommended amount of carbohydrate in your pre-training meal will depend on your blood glucose levels in the morning. (Ideally you want to chat to your sports dietitian about these recommendations and your training and treatment plan).
4. During exercise
The fuel (and how it is used by the body) is the same for both diabetic and non-diabetic athletes. Therefore, for an effort of more than 60 minutes, additional carbohydrate is required at a rate of 30-60g per hour. It is important to meet this need in small amounts, regularly. The type of carbohydrate consumed during exercise does not have as much of an impact on blood glucose levels as does the amount and timing of carbohydrate intake.
5. After exercise
Carbohydrates should be eaten soon after completing exercise to promote recovery and muscle glycogen resynthesis. More strenuous sessions will require more carbohydrate, but the amount will be determined by the intensity, duration of the exercise and individual insulin sensitivity. Another meal or snack containing carbohydrate should be consumed after 60 minutes to further enhance blood-glucose control and recovery of fuel reserves.