The Second Cornerstone of Treatment: Exercise
The specifics of the patient's need for exercise will be determined by the patient and the health care provider. It is important for the patient to know that exercise a) is an important component of successful diabetes control, and b) reduces blood glucose. Regular, daily exercise – starting slowly and gradually increasing in time and effort, based on the individual's tolerance (as determined by his/her health care provider) – can have a positive impact on many aspects of his/her life: metabolic, cardiovascular, weight control, and stress reduction, not to mention the social contacts some exercise plans allow.
Recommendations for Exercise – In General and for the Person with Diabetes
As recommended by the U.S. Department of Health and Human Services (2008) and endorsed by the American Diabetes Association in 2016, adults over the age of 18 should perform exercise of moderate intensity at least 150 minutes each week along with muscle-strengthening activities involving all major muscle groups at least three days each week. In 2016, The American Diabetes Association endorsed as a “position statement” on physical activity/exercise and diabetes a report published in Diabetes Care by Colberg et al. (2016):
Most adults with diabetes should engage in 150 min or more of moderate-to-vigorous intensity activity weekly, spread over at least 3 days/week, with no more than 2 consecutive days without activity. Shorter durations (minimum 75 min/week) of vigorous-intensity or interval training may be sufficient for younger and more physically fit individuals...
Children and adolescents with type 1 or type 2 diabetes should engage in 60 min/day or more of moderate or vigorous intensity aerobic activity, with vigorous, muscle-strengthening, and bone strengthening activities included at least 3 days/week (p. 2069).
If you completed the self-study entitled, Diabetes Mellitus Fundamentals: A Review and Current Update, you should recall the learner activity in which you calculated the net effect of changing insulin, food intake, and/or exercise. Barring other changes, one's blood glucose will decrease with exercise and increase without it. Thus, one must plan exercise knowledgeably. If you have completed that Learner Activity in the other self-study, you can skip the rest of the next paragraph and continue with the self-study.
If you have not completed the identified self-study, consider for a moment what would happen to the blood glucose if insulin were increased while food intake and exercise remained the same as usual. The blood glucose would go down, right? Likewise, think about what would happen if insulin and exercise stayed the same but food intake increased. Clearly, this would result in the blood glucose rising. Now, consider that insulin is increased, food intake is decreased, and exercise is increased. What is likely to happen to the blood glucose? You are correct if you said it would drop significantly and could create an emergency state of hypoglycemia.
Planned exercise can be managed if one eats a snack of complex carbohydrate and protein about 30 minutes prior to engaging in it. This provides ready access to glucose that will be used during the experience. As will be discussed later, it is wise for any person who has diabetes and takes medication designed to lower the blood glucose to carry a source of simple carbohydrate (there are many commercially available products, but a sufficient amount of plain hard candy can do the job) with him or her at all times should the blood glucose drop significantly (severe hypoglycemia) during or after exercise, or at any time, for that matter. Such rescue glucose should never be more than an arm's length away from the person who is at risk for hypoglycemia. Patients should be reminded of this – to keep a glucose source in their car, workplace, pocket when walking, bedside table,
That said, avoid giving blank advice to people with diabetes to exercise. While this is an important component of diabetes control, specifics must be given in terms of type, duration, and frequency of exercise, as well as signs and symptoms of cardiac emergency. Some individuals should actually be referred to a physician for a cardiovascular assessment for tolerance of exercise, before being advised to exercise. Remember that diabetes and heart disease tend to be related; it could be life threatening for a previously sedentary individual with diabetes to initiate an intensive exercise program.