I have recently taken up mountain biking and found that it is the best way for me to relax and de-stress after a long day at work. The problem I am having is with my blood sugars. No matter what I do, I cannot stop them from dropping (which of course is to be expected with exercise). I have tried protein bars, disconnecting (which leads to highs), temporary basals, stopping every 30 minutes to retest and snack, etc. but, out of nowhere, my sugar will just dive. I have a CGM but don’t want to risk riding with it for fear of breaking the device. My endocrinologist has no advice for me except to quit the sport, which I refuse to do. After nearly nine years with diabetes, I know that simply having the disease isn’t going to make me stop something I love simply because I have it. What do you suggest?

Before we dive into the issue, take a minute and pat yourself on the back. You’ve found an activity that you enjoy, and it sounds like you’re getting some mental benefits from it; that�s a huge win for you! Don’t quit!

So now, let�s look at the problem, the lows. Since the lows are caused by insulin with the addition of the exercise, if you lowered the amount of insulin you’re getting you might get closer to where you want to be. You don’t want to cut the flow of insulin off completely (like when you disconnect) but you can decrease the amount of insulin you’re getting. Have you tried a temporary basal at all yet? One of the benefits of pumping is that you can lower the amount of basal insulin that you’re getting at any time. This is great for long car rides, for times of sickness, and for exercise. You can vary the time you start your temporary basal, and you could also vary the amount you want to decrease your basal rate. Most people I talk with that use this in their exercise regimens start their temporary basal anywhere from 30 to 60 minutes prior to exercise, and the amount they decrease their basal rate by depends on the exertion of the activity. It will take some experimenting, but this should help.

BF

[Editor’s comment: Have you tried “carb loading” or such prior to biking, perhaps taking a smaller dose of insulin for the food than you would if not biking? Maybe a higher protein meal about four to eight hours before the ride would help, too.

BH]