I am 70 years old, diagnosed with type 2 diabetes about two months ago, and starting an exercise program. I am on a diabetes pill once a day. Does a low pulse rate (50) affect the answers to questions about exercise? I recognize that it affects the computation of the target zone, but I’m a little afraid of exercising in that zone. Would a less intense workout still help me? Do you know of an accessible reference on the “crossover” concept in sports medicine?

Absolutely! A less intense workout will still help you with regard to lowering blood sugar and improving insulin sensitivity. Your blood sugar drop may not be as dramatic as that which can occur with a more intense workout, but the benefits are definitely there. Even activities which many people wouldn’t necessarily consider “exercise”, such as gardening, house cleaning, parking the car further away and walking to your destination, all count with regard to diabetes management and caloric expenditure. Although regular aerobic exercise is the “ideal”, don’t give up on the little things. All levels of activity count!

Please recognize that the target heart rate is very individual and can be affected by certain classes of medications which control blood pressure and lower heart rate. You don’t say whether you take any of these medications, but your low resting heart rate may be related to this issue. I work in a cardiovascular rehabilitation setting, and we have participants whose target heart rate is 70-100 beats per minute, while others have heart rates higher than that sitting down. That is perfectly okay, and all will benefit from exercise! Your target heart rate can be calculated specifically and individually based on results of an exercise stress test, by a clinical exercise physiologist or health care professional who is familiar with this concept. An exercise stress test as a screening for cardiovascular disease is recommended for people with diabetes in your age group prior to beginning an exercise program. Ask your physician about this standard of care.

The “cross-over” concept which you mention is a standard concept in exercise physiology explaining the contribution of energy sources (glucose,fats, and protein) during exercise, and the changes that occur as the body optimizes the process due to training. The resource that you mention is a good one. So too is The Diabetic Athlete by Sheri Colberg and Edward Horton.

DMW