The Effect of Exercise on Blood Sugar

Those lazy, hazy, crazy days of summer might inspire lounging by the pool or sipping a cool drink under an umbrella. But do not let the long, warm days pass by without exercising on your weekly planner.

Exercise is one of the best ways to stay healthy. Exercise can help prevent health conditions, including stroke, high blood pressure, arthritis and even types of cancer. CDC reports that research finds that adults who engage in greater amounts of physical activity reduce the risk of developing the following cancers, including bladder, breast, colon, kidney, lung, esophagus, stomach, and endometrium. [1]

In addition to its health benefits, physical activity can lift your mood, boost energy, and improve cognitive function and sleep.

The upside of exercise and blood sugar

If you have diabetes, exercise should be part of your diabetes management plan. Exercise can lower blood glucose levels and improve insulin sensitivity. That is because using your muscles when you exercise helps to burn glucose and improve the way insulin works. Harvard Health points to studies that underscore the value of exercise for glucose control. Among the studies: [2]

·         Exercise lowered HbA1c (a blood test that shows your average level of blood glucose, also called blood sugar, over the past two to three months) values by .7 percentage points in people who were from different ethnic groups and who also were taking different medications and following different diets.

·         All forms of exercise - aerobic, resistance or a combined training of both – were equally effective in lowering HbA1c value among diabetics.

 

Weekly targets for exercise and blood sugar levels

 

Understanding the value of exercise to help control diabetes raises questions about how much exercise should go into a diabetes exercise plan. While any exercise is better than none, the American Diabetes Association (ADA) notes that most health organizations recommending exercising a minimum of 150 minutes per week to achieve significant benefits. The exercise does not need to be all at one time, either. ADA says to think of a diabetes exercise plan as a series of mini goals. A goal could be to exercise 50 minutes three times a week, 30 minutes five times a week, or even 25 minutes six times a week.[3]

Exercises for controlling blood sugar levels

What we know about different exercise and blood sugar levels:

Walking: Exercise and blood sugar management does not require an investment in expensive home gym equipment. Exercise can be as simple as walking. Research shows regular walking training, especially when supervised, improves glucose control in subjects with Type 2 diabetes. Walking also had favorable effects on cardiorespiratory fitness, body weight, and blood pressure.[4]  Walking also helps to improve balance, lower blood pressure and stress, and build bone and muscle strength. And the risk of injury from walking is low. All you need are comfortable shoes with good support.

Aerobic dance: Research conducted in 2023 found that aerobic exercise can have a positive impact on glycemic levels in people with prediabetes. [5]

Swimming: Swimming and other aquatic activities, such as water aerobics, offer your heart, lungs and muscles a workout without putting stress on your joints. A 2020 study concluded that water-based circuit training seems effective for improving aerobic fitness, strength, and vascular function for those with Type 2 diabetes. [6]

Interval training: As part of exercise and blood sugar management, consider interval training. This involves short bursts of vigorous exercise, such as running and cycling, combined with short rest periods of up to three minutes. [7]

Resistance (anaerobic) training: Build muscle strength with brief, repetitive exercises using weights, resistance bands, or your own body weight. Choose a range of exercises – six to eight – that target major muscle groups. [8]

Yoga: Yoga is a means to balance and harmonize the body, mind, and emotions. A recent scientific review points out that yoga practice is useful in the management of various lifestyle diseases, including Type 2 diabetes. Doing yoga daily helps to maintain glycemic control and reduces the risk of complications in people with diabetes.[9]

 

Why blood sugar may rise with exercise

While exercise generally helps to lower blood sugar levels, some types of exercise can contribute to a rise in exercise. Heavy weightlifting, sprinting, interval training, and competitive sports contribute to the production of the stress hormones such as adrenaline. It stimulates the liver to release glucose to adjust to the demands of exercise. The change may be short lived.

Another consideration regarding exercise and glucose levels has to do with the food you eat. Carbs can fuel a workout. However, your workout may not be enough to keep blood glucose within your target range if you eat too many carbs before or while you exercise. [10]

Rather than eliminating exercise because of potential to raise blood sugar, here are strategies to keep blood glucose from rising:[11]^,[12]

·         Combine anaerobic and aerobic exercises. This type of exercise regimen balances the effects and typically lowers blood glucose levels soon after the exercise session is over.

·         Minimize the adrenaline effect by practicing relaxation techniques, such as fast paced breathing, visualization, or meditation before and during the workout.

·         Avoid eating large amounts of carbohydrates before and during workouts. For energy, consider peanut butter or yogurt with nuts.

 

Best time for exercise and blood sugar management

When it comes to the best time for exercise and blood sugar management, recent studies indicate that afternoon or evening exercise may be better for blood glucose control in those with Type 2 diabetes.[13] But in the end, practicality wins out. The American Diabetes Association (ADA) suggests that the main conclusion for people with diabetes is to try to develop an exercise routine they can stick with so they achieve success.[14]

It is always advisable to talk to your healthcare team before starting a new fitness program to avoid health risks and ensure safety.