Can Exercise Timing Impact Your Blood Sugar?

Have you been finding the reason you can’t control your glucose consistently? All this time, you have been running on the treadmill for hours or skipping your favourite chocolates, and yet there is little to no progress in regulating your blood sugar. Well, your exercise timing may be the culprit!

In one study conducted, the researchers suggested that the afternoon or evening could be the best time to exercise, while morning exercises have no effect on insulin reduction. Of course, a healthy post-meals workout also plays an important role in blood sugar management.

Why is exercise needed when you have diabetes?

People suffering from pre-diabetes and diabetes are encouraged to exercise to keep their health on track. Many research studies have proved that exercise is needed to improve their condition [1].

It may seem overstated, but people with diabetes can truly gain a lot of health benefits by simply exercising daily. It primarily aids in controlling weight – especially for those obese who eventually develop diabetes, lowering blood pressure and decreasing harmful low-density lipoprotein (LDL) cholesterol. Aside from this, diabetic people can also strengthen their muscles and bones, reduce anxiety and enhance their overall well-being when they do consistent exercise.

On top of the mentioned, the most important benefits of simple exercise specific to drastically improve the condition of diabetes are lowering blood glucose levels, boosting the body’s sensitivity to insulin and countering insulin resistance. There are numerous studies that strongly emphasised the benefits of exercise. Some of their conclusions can be drawn from the following:

Exercise has long been linked to good health, but recent studies are shedding more light on how useful it can be in helping you to live longer. — Photograph: Anna Shvets

Exercise can lower HbA1c values by 0.7 percent. One study concluded that exercising could lower the HbA1c values by 0.7 percent of people in various ethnic groups who are suffering from diabetes, particularly those who are taking different medications and following strict kinds of diets. This decrease in HbA1c values can occur even though the individual did not lose weight during the period of consistent exercise.

Note: The HbA1c or also known as the haemoglobin A1C, refers to a simple blood test that can measure one’s average blood sugar levels within the past 3 months. When your HbA1c test result comes out high in value, it means you have too much blood sugar in your blood – this is simply alarming for diabetic patients.

All forms of exercise are good. Whatever kind of exercise you have in mind is essentially good for diabetic people. There are 5 major types of exercise that you may want to choose from: (1) strength training, (2) aerobic training, (3) balance and stability training, (4) coordination and agility training and (5) flexibility and mobility training. All these forms of exercise are equally good in decreasing HbA1c values for people with diabetes.

Particularly, resistance or strength and aerobic exercise training can help decrease insulin resistance of previously sedentary older adults who have abdominal obesity and are at high risk for diabetes. By combining these two types of exercise, people with diabetes can improve their condition.

Exercise timing can affect blood sugar

Now, let’s go to the intriguing part. Exercising itself may not be effective if you are doing it at the wrong time, especially for people with diabetes. As exercise can make the body more sensitive to insulin, doing it the wrong way and time can increase the risk of blood sugar dropping too low [3]. Hence, people with diabetes must check their blood sugar more often before and after exercising. Regular checking of your blood sugar levels can help you understand your body better and how it responds to your exercise routine.

More importantly, a new strategy emerged derived from a research study published by Diabetologia. People with diabetes can manage their blood sugar levels better by exercising at a specific time.

Health researchers recommend thinking about the time you work out, as this is an essential factor in bettering and managing your blood sugar control [4]. In this work, the researchers have 775 participants that are a combination of men and women aged from 45 to 65 years old. Each of them was given a fitness tracker and paced into one group out of three: (1) morning exercise group, (2) afternoon exercise group and (3) evening exercise group).

The results are interesting as there were no changes to insulin resistance for the group who did an exercise in the morning. However, there are significant changes for the other two groups. For the participants who did moderate to vigorous physical activity in the afternoon, they had reduced their insulin resistance by 18 percent while the evening group fared even better as they lowered their insulin resistance by 25 percent.

Is it better to exercise soon after eating?

In another study made in 2017 and published by the journal Frontiers, experts stated that glucose levels generally hit their peak within 90 minutes of a meal [5]. People with type 2 diabetes are required to keep their glucose levels at 160 mg/dl within two hours of a meal. As exercising can basically reduce blood glucose concentrations, it is always a good practice to start exercising around 30 minutes after the beginning of a meal, researchers explained. While this is a strong guideline, note that it still can vary for different people.

Lowering your blood sugar

You are considered to have low blood sugar when your level drops below 70 mg/dl. Exercising fuels your muscles with sugar and free fatty acids to convert and generate energy. Moreover, moderate to intense exercise can cause your blood sugar to drop during and after 24 hours.

Basically, during the first 15 minutes of your exercise, the majority of the sugar for fuel comes from either your bloodstream or the muscle glycogen that is converted back to sugar. In the next few minutes after the 15-minute mark, the fuel will then start to come more from the glycogen that is found in the liver. After 30 minutes of exercise, your body begins to get more of its energy from the free fatty acids. With your body processing during exercise, physical activity can definitely deplete the sugar levels and glycogen stores [6].

When to tell if it is safe to exercise?

Start by checking your blood sugar first before doing any exercise or intense physical activity. Your body releases stress hormones at the beginning of your exercise session, causing it slightly to increase your blood sugar. For people with diabetes, their blood sugar may increase a lot during 30 minutes of workout, then will eventually die down.

Health experts also reminded people with high blood sugar to prevent exercising because it may be harmful to them. Hence, they may need to wait for their blood sugar to lower before exercising. Some important reminders to follow to make your exercise safe while managing your blood sugar level.

Your blood sugar must be between 150 and 180 because this is a healthy range.
It is not safe for people with blood sugar lower than 140 and also taking insulin to exercise. To reverse this, you should eat 15 grams of carbohydrates prior to exercise, so the level won’t drop too low.
It is also not safe for people with really high blood sugar levels, around 300 or more, to exercise. You may want to skip exercise for a few hours or a day and try to take a small amount of insulin before starting.
After exercising, people who take insulin must check their blood sugar level to secure enough fuel.

People with diabetes can dramatically improve their condition by simply having a consistent workout or exercise routine. It is recommended for them to track their blood sugar levels for about four to five hours after consuming post-meal exercise to see what their trend is. With this practice, it can help them determine their levels if they are healthy or alarming.

Keep in mind that any exercise can be beneficial in managing your blood sugar. It is preferable to do it in the afternoon and evening to maximise your time and effort in maintaining your body on track, especially if you have diabetes. Your body may respond differently compared to others due to some factors; hence, it is always better to consult your doctor if you have other medications and health issues.