Low blood sugar can be prevented (and shouldn’t stop you from hitting the gym).
You already know that exercise is one of the most powerful tools for managing diabetes and its complications. In a 2015 study, regular exercise was associated with lower A1C levels, lower body weight, and improved cholesterol levels among patients with type 2 diabetes. And it doesn’t require daily gym sessions: A study in Diabetes Care found that resistance training just twice a week for four months reduced fasting blood glucose levels by 7.1 percent for older men with type 2 diabetes. Here’s more info about how exercise helps manage diabetes.
But a word of caution: If you have diabetes, there’s a chance that exercise may lower your body’s blood glucose levels too much. “It’s important [for patients] to monitor their blood sugar before, during, and after exercise,” says Joan Pagano, an exercise physiologist in New York City. “The danger is, as cells take up the blood sugar from the bloodstream, it can cause hypoglycemia or low blood sugar.”
Hypoglycemia may not affect all people with diabetes. Those who take insulin or oral medications known for lowering blood sugar are more at risk for low blood sugar during exercise, according to Minisha Sood, MD, an endocrinologist in New York City. “It’s important for them to check their blood sugar before exercise to make sure it’s not below 100,” says Dr. Sood.
That doesn’t mean taking insulin should stop you from reaping the benefits of exercise, though. “If you feel shaky or confused at any time, you should stop the exercise and have a snack,” says Pagano. Juice boxes are an easy way to introduce sugar to the body quickly, but other options include nuts, bananas, or glucose tablets. The American Diabetes association recommends having 15 to 20 grams of carbohydrates if your blood sugar falls below 100. (That’s about half a cup of juice.)
If you are prone to hypoglycemia, your doctor may recommend a glucagon pen, according to Sandra Arévalo, RDN, a spokesperson for the American Association of Diabetes Educators. If you start to feel like you may faint, the glucagon pen can quickly help bring glucose levels up to a healthy range.
Even if your numbers look A-OK at the end of your cycling class, it’s a good idea to keep an eye on them afterward, especially if you’ve changed or increased the intensity of your workout routine. Hypoglycemia can occur up to 12 hours after your workout, which experts call the “lag effect.” That’s because the body is working to replace your glycogen stores.
After exercising, keep monitoring your blood sugar and looking for symptoms of hypoglycemia—like shakiness, weakness, or blurred vision—for several hours. (Learn more about the signs of hypoglycemia and hyperglycemia and how to treat them here.)
To manage blood sugar safely, here are essential tips for exercising with diabetes.
Dr. Sood is a board-certified endocrinologist in private practice in New York City and an assistant professor at Hofstra School of Medicine.Joan Pagano
Joan Pagano is an exercise physiologist in New York City.Sandra Arevalo
Sandra Arevalo is a spokesperson for the American Association of Diabetes Educators and Academy of Nutrition and Dietetics and director of nutrition services and community outreach at South Bronx Health Center.
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People with diabetes have to take a
variety of precautions before, during, and
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00:00:07,570 --> 00:00:12,636
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One thing that people with
diabetes need to know is that it's
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important monitor their blood
sugar before, during, and
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after exercise because the danger
is that with exercise.
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As the cells take up the blood sugar
from the bloodstream, it can cause
00:00:26,750 --> 00:00:30,300
hypoglycemia or low blood sugar.
It's not as much of a concern if
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they're taking medications that
don't drop their blood sugar.
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But if they're taking insulin or
sulfonylureas or meglitinides,
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hypoglycemia can occur pretty frequently.
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It's important for them to check their
blood sugar before exercise to make sure
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it's not below 100.
If you're on insulin make sure that
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you have your insulin in
case your sugars go high.
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And that you also have like
a glucagon pen, glucagon pens are for
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people who have the tendency
to drop their sugars too much.
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So if your sugar is dropping and
you feel like you're gonna faint,
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you need to use it.
If you feel shaky or
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confused at any time you
should stop the exercise and
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have a snack.
For most people with diabetes it is
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important that they get like,
the glucose pills, for example.
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Or even like a juice box, something
that can give you sugars very quick.
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However, if that's not available, some
other snacks that they can get is, for
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example, bananas, I love bananas.
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Having nuts in your bag, that helps,
it will give you a little bit of protein,
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it will help to maintain your
sugars at a normal level.
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Keep hydrated, if you dehydrate, your
sugars are gonna get very concentrated,
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so be drinking throughout
your exercise routine.
00:01:44,390 --> 00:01:47,290
Hypoglycemia can occur up to 12 hours
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after a bout of exercise.
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So you need to continue to monitor it for
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at least several hours after you
finish your exercise program.
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Blood glucose and exercise. Arlington, VA: American Diabetes Association. (Accessed on April 2, 2021 at http://www.diabetes.org/food-and-fitness/fitness/get-started-safely/blood-glucose-control-and-exercise.html.)Herbst A, Kapellen T, Schober E, Graf C, Meissner T, Holl RW, DPV-Science-Initiative. Impact of regular physical activity on blood glucose control and cardiovascular risk factors in adolescents with type 2 diabetes mellitus—a multicenter study of 578 patients from 225 centres. Pediatr Diabetes. 2015 May;16(3):204-10. Ibanez J, Izquierdo M, Arguelles I, Forga L, Larrion JL, Garcia-Unciti M, et al. Twice-weekly progressive resistance training decreases abdominal fat and improves insulin sensitivity in older men with type 2 diabetes. Diabetes Care. 2005 May;28(3):662-7. Signs and symptoms of hypoglycemia (happen quickly). Arlington, VA: American Diabetes Association. (Accessed on April 2, 2021 at http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/hypoglycemia-low-blood.html.) Why is my blood glucose sometimes low after physical activity? Boston, MA: Joslin Diabetes Center. (Accessed on April 2, 2021 at http://www.joslin.org/info/why_is_my_blood_glucose_sometimes_low_after_physical_activity.html.)