HELP ON DIABETES

Exercise and Type 1 Diabetes

If you have type 1 diabetes, and you are not in the honeymoon period when the beta cells still have some capacity to make insulin, you can have fluctuating blood glu­cose levels, and exercise can be particularly tricky. You may encounter the follow­ing problems while exercising: 

• Delivery of insulin into the body by subcutaneous ( just-under-the-skin) injection makes it difficult to reduce the insulin levels at the start of exercise—this is particularly true in the case of unexpected exercise. The high insulin levels prevent the liver from making sufficient glucose to maintain normal blood glucose levels, and you can become hypoglycemic during exercise. 
• With intense exercise, the increased activity of the sympathetic nervous system can make the glucose go up during and especially after exercise. The rise after exercise can be problematic if the insulin levels remain low. 
• If you participate in a competitive sport, the stress of competition and the adrenaline rush can lead to insulin resistance and increased glucose levels before exercise. 
• Many hours after exercise, the muscles and the liver continue to take up glucose from the blood in order to replenish their glycogen stores. So, in order to avoid hypoglycemia some hours after exercise, you need to decrease your insulin dose or increase your carbohydrate intake. 
• With regular exercise (the training effect), your insulin requirements will generally fall. You will be more insulin sensitive, so you will need to adjust your basal and bolus insulin doses. 
• Exercise can accelerate insulin absorption, especially if the site of injection is near the exercising muscle (for example, the thigh). 

 If your blood insulin levels are low and your glucose level is high before exercise, the combination of high glucose production by the liver and free fatty acid production from the fat stores during exercise can result in high glucose levels and production of ketones, which can lead to DKA. Therefore you have to be cautious about exercising if your glucose is above 250 to 300 mg/dl, especially if you also have urinary ketones.