Monthly Archives: July 2011

“When it comes to diabetes, don’t let the perfect be the enemy of the good enough.” That—or something like it— is what the exercise physiologist at Joslin said. And I agree.

Except that I don’t want perfect. I just want better. Better than where I have been. Better than where I am now. [1]

And where am I now? I exercise/train a lot, but I start out with higher blood glucose levels than I would like—sometimes very high—and I tend to drop a bit more than I’d like, too. (For a while that was about the only predictable thing about exercise.) During a couple of races it brought me to a walk, sucking up major time. I haven’t been able to figure out how much insulin (if any) to give when I eat during multi-hour bike rides. And then, of course, I have really good days, too.

I don’t expect perfection. I’d settle for predictability, though I’d really like something closer to “normal” BGs for two main reasons: Better BGs mean better performance, and higher BGs mean a greater risk of long-term complications. I know I have a disease, but I also know that I’ve had great experiences with it. I want more of those. Figuring out how to do that will keep me safer, healthier, and happier.

So I finally got around to reading a book that’s been on my shelf for about 18 months: the second edition of The Diabetic Athlete’s Handbook by Sheri Colberg. (I’d started it multiple times, but I’m a champ at getting distracted.) It’s a shame that it took me so long, because it’s full of great information.

The book has two parts. The first provides some general background on the physiology of exercise—how our bodies use energy—along with how diabetes alters this and the main ways that we can work it. The latter chapters of the book give some recommendations for specific athletic activities: from cycling to kickboxing and everything else.

I found the physiology parts really interesting. [2] The body is a mysterious thing, and I like learning how to make it work well. Here’s a bit of useful information from the book:

• There are three energy systems that get used by muscles. The shortest duration system only lasts about ten seconds. The lactic acid system can go for a minute or so. Then there’s the aerobic system that powers endurance activity and can last for hours.
• Consequently, the intensity and duration of activity impact what energy sources your body uses: muscle glycogen, blood sugar, glycogen stored in the liver, fat, etc. Knowing what kind you’re going to use can help you plan how to approach an activity.
• There’s a hormonal response to intense activity—such as sprinting or hill climbing or power-lifting—that reduces the effect of insulin. This can make blood sugar go up and (paradoxically) suggests that brief, four-second bouts of sprinting can help keep BGs from dipping as much during endurance events.
• People with diabetes have almost exactly the same physiological response to exercise and competition as people with functioning beta cells except that we add our own insulin. The rest is quite similar: the amount of calories burned for the same duration and intensity, how long it takes food to hit our blood stream and muscles, the effects of adrenaline and other stress hormones, etc. We (mostly) need the same amount and kind of food to fuel our activities; we have the same hydration needs; we have to prevent the same injuries; and we can benefit from the same mental preparation.
• The lack of our own insulin production (for Type 1 folks) and insulin resistance (for Type 2s) are the tricky bits. (Duh! Those are defining characteristics of diabetes.) There’s an optimal plasma insulin level—usually lower than normal for aerobic activity— that stimulates glucose production in the liver and that enables muscle uptake. Too little insulin, and the liver continues to produce glucose but the muscles can’t take it. (BGs go up a lot.) Too much insulin, and the liver reduces its contribution while the muscles soak up lots of the available blood glucose. (BGs go down a lot.) If you can find the (ahem) sweet spot, BGs should stay pretty stable and cause the body to use the energy source(s) as in a person without diabetes.
• Exercising in the morning is frequently easier for most people because of the lack of recently bolused insulin and because of all those happy wake-up (stress) hormones.
• Aerobic (endurance) activities make insulin more potent, both during exercise and for 12-48 hours afterward, as it moves glucose out of your bloodstream to replenish your muscle glycogen stores.
• Hypoglycemia begets more hypoglycemia. If you’ve been low in the last 24 hours or so, the stress hormones that would help prevent it during exercise are inhibited. Your chances are much higher that you’ll be hypoglycemic again.
• Evidently, having girlie parts also makes a difference with diabetes and exercise.

There’s so much information in the book—including some charts that might help you determine how much to change your insulin dosages before exercise and events—that it’s really worth getting your own copy and going through the first 125-or-so pages.

I’m going to sum up the remaining 140-ish pages, which are also very useful, this way: Whatever Works. Colberg divides more than 60 different sports and activities into five general categories, gives some guidelines about how to approach them diabetes-wise, and then provides a bunch of information from different athletes about what works for them.

That last part of each section was the most instructive aspect of the book for me. Technically, it didn’t teach me much new, but it let me know that there’s no best way—much less one right way—to approach exercise and sport with diabetes. In one paragraph an athlete describes what works for him or her, while the next shows someone doing something that seems almost 180-degrees opposite. There may be a half-dozen “right ways” to exercise or compete in an event with diabetes. Not only may your diabetes vary from mine, but it might be possible for the same person to get to the same outcome (more or less) consistently using different techniques.

Whatever works. The key then becomes finding what works for you. This book can help get you there by understanding what your body is likely to do for different activities and then providing you some suggested starting points and anecdotes about what has worked for others.

From there it’s all trial and error . . . and note-taking. But that’s something to take on next time.

1 — And by “now,” of course, I mean a couple weeks ago when I started writing this post. [Back . . .]

2 — Full disclosure: The year-long course in anatomy and physiology was my favorite high school class. [Back . . .]