Exercise impacts your blood sugar, so you need to make sure your levels aren’t too high when you start exercising, but also not so low that they’ll plummet during your workout. So while a study published in November 2010 in the Journal of Physiology found that not eating before exercise helped people burn fat, people with diabetes need to maintain blood sugar levels, and should plan to eat before, after, and sometimes even during exercise, Bland says. That’s the general recommendation, but it’s not a one-size-fits-all approach. You need to keep an eye on how your body responds, since “some people are more sensitive to the effects of exercise versus others,” Bland says. Not sure where to start? Bland recommends working with an endocrinologist or an exercise physiologist to establish blood glucose targets and an exercise plan that’s safe for you. No matter what, you’ll want to check your blood sugar before working out so you know how to fuel up. Your goal is a level greater than 100 milligrams per deciliter (mg/dL) — but always skip the workout if your blood sugar is at or higher than 250 mg/dL and ketosis is present, or greater than 300 mg/dL without ketosis. Be sure to talk to your doctor about your blood glucose targets before and after exercise.
The Best Pre-Workout Snacks
Your best bet is eating a balanced meal an hour to an hour and a half before your workout, says Lori Zanini, RD, CDE, creator of the seven-day diabetes meal plan. Shoot for 30 grams (g) of high fiber carbohydrates, 3 to 4 ounces (oz) of lean protein, 5 to 10 g of healthy fats, and two servings of nonstarchy vegetables (a serving is 1 cup of raw veggies or ½ cup of cooked veggies), Zanini says. A turkey sandwich on whole wheat bread with ¼ of an avocado, lettuce, tomato, and 1 cup of sugar snap peas on the side checks all the boxes. If you’re short on time or knocking out your workout first thing in the morning, adjust your approach and grab a snack that combines protein with healthy carbohydrates (ideally 15 grams) 15 to 30 minutes before exercising, says Jessica Crandall, RDN, CDE, wellness center director at Denver Wellness and Nutrition in Englewood, Colorado. The carbs-plus-protein combo “helps you keep your blood sugar stable for a longer period of time,” she says. Try a hard-boiled egg and 1 cup berries, 1 cup of cottage cheese, and ½ cup of pineapple, or 1 to 2 tablespoons (tpsp) of peanut butter and an apple, Zanini says.
What to Reach for During Exercise
Depending on how long and how intense your workout is, your blood sugar can decrease as you’re exercising. Keep a snack with about 15 to 20 g of carbohydrates nearby — Crandall likes dried fruit because it’s easy to stash in a workout bag — and reach for it if hypoglycemia occurs, Bland says.
The Best Post-Workout Snacks
As you exercise, your body will use insulin more efficiently, which lowers your blood sugar for up to 24 hours, creating what’s known as the “lag effect.” “This puts an individual with diabetes at risk for hypoglycemia in the hours following exercise completion,” Bland says. To counter it, reach for a snack within 15 minutes of your cooldown. The snack should have 15 g of carbohydrates, which is about what you’ll find in ½ cup of oatmeal, 1 cup of berries, or half of a medium-sized sweet potato, Zanini says. Crandall suggests adding protein, such as nuts, string cheese, or cottage cheese, to help support muscle mass. Finally, sit down for a meal within an hour or two, Zanini says. Just be careful not to overdo it. According to the American Diabetes Association, you likely won’t need to add any extra carbs to your diet, unless you’re exercising for longer than an hour. It’s easy to adopt the “I just worked out, so I deserve this doughnut” reasoning, but going overboard could cancel out your exercise efforts.
