Diabetes Prevention Guide
En español | If ever there was a time to get serious about exercise, a prediabetes diagnosis is it. Study after study (after study ...) shows that regular exercise can help you to keep from crossing that line into type 2 diabetes — and to avoid the serious health consequences that come with it. If you already have diabetes, working out is key to managing blood glucose levels.
"Exercise is what helps prevent and treat the disease itself,” says Kara Mitchell, wellness manager at the Duke Health and Fitness Center in Durham, N.C. “The more we use our muscles, the better our body can take in glucose and use it appropriately.”
Ready to get started? Here are some tips to keep in mind — including the optimal time to schedule your workouts to best fight diabetes, and the specific types of exercise to consider.
Get the green light from your doctor
If you're just starting out, talk with someone on your health care team—your doctor or diabetes educator — to help map out an exercise strategy that makes sense for you, especially if you take insulin. The American Diabetes Association (ADA) recommends at least 150 minutes per week of moderate-intensity aerobic activity (a brisk walk or cycling, for instance). That's the number researchers associate with improved blood glucose levels, as well as a reduced risk of cardiovascular disease, stronger bones and improved mental health.
"If you're just starting out, begin with 10 to 15 minutes per day of what feels like moderate exercise — that means that while exercising you should be able to complete full sentences, but it should be difficult to sing — and increase that by three to five minutes every week,” suggests Matthew Schoenherr, a clinical exercise physiologist and certified diabetes educator in San Diego.
To stay motivated, make sure your exercise plan syncs up with your interests, abilities and lifestyle (can you stick with swimming if the nearest pool is a 45-minute drive away?). For instance, if you have nerve damage, vision loss or arthritis — all complications of diabetes — your health care provider may recommend specific ways to reach that 150-minute mark. Something else to keep in mind: You can exercise in increments — 20 minutes at lunch, 15 minutes after dinner — and reap the same health benefits.
Schedule your workout
Exercise can easily get bumped to the bottom of anyone's to-do list, especially if you're managing the demands of a chronic disease like diabetes. That's why it's important to schedule your workouts as you would any other must-do activity.
Research suggests the best time to be physically active if you're trying to keep blood glucose in check is one to three hours after eating, when your blood sugar level is likely to be higher. That's because “exercise acts like insulin in the body — it directly reduces blood glucose levels,” says Mitchell, echoing the results of a study published in 2017 in Diabetology & Metabolic Syndrome. Researchers found that people with type 2 diabetes who took brisk 15-minute walks 15 minutes after meals had lower blood glucose than those who took a single 45-minute daily walk before breakfast.
Other research suggests even a little post-meal exercise — walking up and down stairs for just three minutes — can improve blood glucose in people with type 2.
If your daily routine doesn't lend itself to being physically active after eating, don't let that stop you. Most experts agree: The best time to exercise — whether you have diabetes or not — is any time you can squeeze it in. “You can argue there are small benefits with certain times of day, but what matters is when you will realistically exercise,” says Mitchell. “Stick to that."
It's easy to equate “exercise” with aerobic activity. But strength training (such as lifting weights or using a resistance band) plays an equally important role in lowering A1c, the results of a test that measures average blood glucose over the past three months. For people with prediabetes, an increase in overall muscle mass can reduce by 32 percent the risk for developing full-on diabetes, according to Mayo Clinic research.
"Your muscles have memory,” explains Richard Peng, a clinical exercise physiologist and certified diabetes educator at HealthCare Partners medical group in Los Angeles. “When you exercise, you're teaching your body how to store the sugar in your muscles rather than the bloodstream. The more you exercise, the more your body will effectively use the sugar.”
Aim for two or three strength-training sessions per week, on nonconsecutive days. And, if possible, combine those with aerobic exercise. Research shows that doing both types of exercise in a single workout results in even greater improvements to blood glucose levels.
Check your blood glucose
Physical activity can lower your blood sugar for 24 hours or more after your workout by making your body more sensitive to insulin. The best way to figure out how your body reacts to a particular exercise plan is to check your blood sugar level right before and right after working out, especially if you take insulin or are on a medication that causes your pancreas to make more insulin. Keep a log so you can discuss any problems with your doctor.
Also keep a snack handy in case your blood sugar takes a nosedive during your workout. Schoenherr recommends fast-acting carbs such as fruit or dextrose gel packs (check the ingredients to make sure the first one listed is “D-glucose” or “dextrose").
"Otherwise, if you're exercising for less than 11/2 hours, it's not necessary to eat during exercise,” he says. “Some studies suggest that having a ‘recovery meal’ within 30 minutes of exercise can further improve insulin sensitivity. Other studies have suggested that it may also curb your appetite for the rest of the day.”
Wear a medical ID tag or bracelet when you work out so others will know how to help if you experience symptoms of low blood glucose (hypoglycemia). And be sure to keep your water bottle handy during long bouts of physical activity, especially during summer months. Dehydration can do a number on blood glucose levels.