Staying Safe During (and After) Vigorous Exercise

Q: My husband has type 1 diabetes and is training to ride in a 65-mile bicycle race. How can he best control his blood sugar levels during and after this race? His levels sometimes crash a few hours after training.

A:First, I would like to congratulate your husband on having the remarkable discipline such an activity requires. This is long and strenuous exercise. I am assuming that he has been evaluated and cleared by his doctor to participate in such physical activity, so I will focus on glucose control. When engaging in arduous exercise, people who have diabetes should be vigilant about preventing both high and low glucose levels.

The risk of low sugar levels is more intuitive to understand than high sugar levels because the body uses so much energy from glucose during exercise. In addition, after exercising, the body tries to replenish the energy stores of the muscles and the liver, which can also lead to abnormally low blood sugar levels.

High sugar levels can develop because the body considers long and strenuous exercise a form of stress. Any type of stress triggers the production of adrenaline and other hormones that inhibit insulin and increase the production of glucose. Here are some general guidelines.

Before training begins, your husband should have his diabetes controlled very well with intense insulin therapy, either with three or more injections a day or with an insulin pump. This allows for better flexibility during his training and race.
During his training weeks or months, your husband should monitor his glucose levels both before and after meals. He should also track the amount of insulin he injects, his dietary intake, and the duration of each exercise or training session. He should also check his glucose levels at 2 a.m.

Before he starts his training sessions, he should determine his glucose level. The ideal glucose level is 100 to 250 mg/dl. If it is below 100 mg/dl, then he must eat a snack containing carbohydrates. If it's above 250 mg/dl, he should also check for the presence of ketones in his urine. Ketones are the by-product of fat energy metabolism. The body reverts to this process when it lacks sufficient amounts of insulin. If he has urine ketones, he should refrain from exercising until the insulin deficiency is corrected. If his sugar is above 300 mg/dl, he must postpone his training session until his levels are corrected.

While he's training, your husband should check his glucose level frequently. He should also carry drinks that contain carbohydrates, or sugar tablets, to compensate for low levels. Having a "map" of his sugar levels (see step 2) will provide him a reference to base his insulin requirement on as well.

After exercising, your husband's body will try to restore the glucose in his muscles and liver, so it will continue to remove glucose from the bloodstream. This leads to low sugar levels even hours after he's through exercising. Your husband must check his glucose level immediately after exercising and several times later, for up to 12 hours afterwards.

Based on the records he has kept on his glucose levels, he may need to reduce his insulin dose by more than 50 percent.

It is best to exercise at least 30 minutes after injecting insulin to limit the effect of exercise on insulin absorption. If your husband exercises in the afternoon or evening, he might find his glucose level to be abnormally low in the middle of the night — his bedtime or evening insulin doses would have to be adjusted accordingly. If your husband is on NPH, the evening dose should be given at 10 or 11 p.m. Your husband will probably need to increase his carbohydrate intake in the evening to prevent low blood sugar levels in the middle of the night.

It is also generally recommended that diabetic athletes have a meal two to six hours before exercising. It should contain 83 to 200 grams of carbohydrate, a small amount of protein, and fat.

Start Good Habits Early

Starting off with the right approach is really important for two reasons: First, it’s usually easier to get your diabetes under good control in the early stages of the disease, and secondly, clinical studies show that achieving good control early provides benefits to your body that can last for decades.

Also, the diabetes habits you develop now will stick with you in the long-run. Really, we all know how hard it is to change behavior once we’re set in our ways!

So for example, you might want to take some time to look at the user’s manual that came with your glucose meter in order to learn how to set the alarms that will remind you to test at different times of day: before meals, about two hours after, and at wake time and bed time. You want those test times to become habit!

You’ll also want to set up some kind of reminders to get your essential medical tests done regularly:

the A1c blood test - every three months
blood pressure - every six months at least (take advantage of every doctor’s appointment to have this checked, especially if it’s been elevated or you’ve had concerns)microalbumin, lipids, and eye exam—all annually (unless concerns call for more frequent checks)

Another “habit” that you’ll want to nurture early on is keeping an upbeat attitude. The voice in your own head is very, very important: you’ll want it to act as a “cheerleader,” rather than a negative force always telling you that you’ve failed.

There’s no question that it’s hard to stay upbeat when you’ve been diagnosed with a chronic illness.

You might be thinking: How do I stay positive when I feel like I’m being punished? Or when I feel so overwhelmed by having a disease that requires so much attention?

Taking care of yourself with diabetes is indeed a “mental game,” requiring you to learn to function comfortably on a number of levels:

Personal (Emotional)—fighting off negative thoughts
Social—interacting with others in social situations without stress
Behavioral—preventing yourself from doing things you wish you wouldn’t, sometimes even self-destructive things

If you do find that you’re experiencing a mental struggle with your diabetes, connecting with other people walking in your shoes is often very comforting – and helpful.

Connecting with other PWDs (people with diabetes) regularly, either online or offline, is a habit worth forming!

Is There a 'Safe' Blood Sugar Level?

Q: What is the "safe" blood sugar level? I have heard several opinions from other diabetics, and I am very confused. I was told that it was 154 about a year ago, and my doctor didn't recommend daily monitoring. At one time on a morning fasting, my level was 74.

— Theresa,

A: Yes, there is a safe blood sugar level. It is the optimum range that safely provides the body with adequate amounts of energy. For the average person, it is 70 to 105 mg/dl in a fasting state. (Diabetes is diagnosed when the fasting blood glucose level is at or above 126 mg/dl.)

Glucose values vary depending on the time of day, your activity level, and your diet. Your sugar level of 154 mg/dl, which is high, may not have been determined while you were fasting. If it had been, a physician would have repeated the test. Your doctor did, and your level was determined to be normal at 74 mg/dl.

In this case, daily monitoring is probably not necessary. If your levels are elevated in the future, you will be diagnosed with diabetes. Treatment can include lifestyle modification, diet, and exercise. If these strategies are not adequate to control your blood glucose level, your physician may prescribe oral medicines or insulin. Having a laboratory examination during your yearly physical and maintaining a healthy lifestyle are adequate for now.

Why is it important to keep your glucose level within a normal range? An excess of glucose in the bloodstream causes various chemical changes that lead to damage to our blood vessels, nerves, and cells. Each cell in the body has a function that requires energy, and this energy comes primarily from glucose. The energy allows you to perform various tasks, including talking and walking. It allows your heart to beat and your brain to produce chemicals and signals that help you think, breathe, regulate your internal temperature, and digest and absorb food. The body is a veritable industrial complex! But this complex is also quite delicately balanced. The very cells that process glucose and convert it to energy can be damaged by excess glucose. Imagine a car engine being damaged when it is flooded with gasoline.

A lack of glucose is also extremely detrimental to the body and can have serious consequences — including death. Without a source of energy to fuel the vital functions of the body, these functions cease.

Good luck with your blood glucose management, and don't hesitate to ask your doctor about ways to maintain and improve your health.