It is well documented that exercise is an extremely important piece of the puzzle for all, but especially for those with high cholesterol, high triglycerides, hypertension, cardiovascular disease, and diabetes. A challenging task is to monitor one’s blood glucose to avoid episodes of hypoglycemia which is a common complication with exercise for people with Type I diabetes (Biankin et al, 2003).

Metabolic control prior to the start of exercise is imperative. The American Diabetes Association (2004) published a position statement that recommends to avoid physical activity if fasting glucose levels are > 250 mg/dl with ketosis present and use caution if > 300 mg/dl with no ketosis. Also, if blood glucose levels are < 100 mg/dl, carbohydrates should be ingested prior to beginning exercise. Carbohydrate-based foods should be readily available before, during, and after exercise to prevent hypoglycemia. Blood glucose levels should be carefully monitored during and up to 24 hours after physical activity to allow for proper insulin adjustment/carbohydrate intake as needed to avoid hypoglycemia (Sandoval et al, 2004 and Derouich & Boutayeb, 2002).

One study (Biankin et al, 2003) reported that no subjects approached hypoglycemia when exercise commenced in the morning prior to eating with morning insulin omitted. This would appear to be a good exercise time. Most recent reports (Grimm et al, 2004; Sandoval et al, 2004; American Diabetes Association, 2004) are in favor of exercising at any time as long as blood glucose monitoring occurs and adequate carbohydrate-based foods are available to prevent hypoglycemic episodes. Grimm et al reports that almost all hypoglycemic episodes can be prevented with adequate carbohydrate replacement and that decreasing insulin dosage does not correlate with hypoglycemic control. Francescato et al (2004) finds that time elapsed from last insulin dose is not a factor influencing hypoglycemia during exercise when a proportional amount of carbohydrates are ingested. Mauvais-Jarvis et al (2003) supports insulin reduction of up to 50-90% to control hypoglycemia with intense exercise of 60 minutes in duration. The important aspect of all these studies is proper self-management of insulin/blood glucose levels. This entails frequent blood glucose monitoring before, during, and up to 24 hours after even low to moderate exercise with appropriate adjustments in carbohydrate consumption or insulin injection to regulate blood glucose. A reading just prior to exercise is important to determine an individual’s pre-exercise glucose level. Readings should also be taken during and after exercise to determine the need for carbohydrate replacement and avoidance of hypoglycemia.

References

Dawn McCrory, PT, LAc; Alicia Perez, PT; Jerry Jordano, PT

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