What is insulin resistance?

Insulin resistance, or insulin insensitivity occurs when our cells no longer respond to insulin as effectively as they used to. Insulin is a hormone that is released by our pancreas when we eat to facilitate the movement of sugars (glucose) from our blood into our cells, where it can be used for energy. We can experience varying degrees of insulin resistance. Long-term insulin resistance results in the sugar no longer moving into our cells quickly or effectively, causing blood sugar to remain elevated – this is often when the diagnosis of diabetes is made. Catching insulin resistance early can help to prevent this.

Insulin resistance is as the heart of all of the cardiovascular diseases. It contributes to high blood sugar and diabetes, non-alcoholic fatty liver disease (NAFLD,) high cholesterol and obesity. It is a vicious cycle since states of hyperinsulinemia (high insulin in the blood) actually amplifies the resistance to it. The good news? We can catch it early, and it is reversible.

How does exercise improve insulin resistance?

There are many things that we can do to start improving insulin resistance, one of which is exercising.

Insulin resistance has shown to improve even after a single bout of exercise, and this effect can last up to 72 hours. Muscle contraction produced during exercise increases the amount of transporters that can bring glucose into cells, so more glucose moves from the blood into the cell, much like the job of insulin. Exercising before meals can increase blood sugar control, while exercise after meals can augment the moment of sugar into cells. The more blood flow we get to our muscles the better glucose control we have, and regular exercise does just this. Although we can see acute benefits, the benefits seen with chronic exercise are superior, and those who exercise regularly demonstrate better insulin sensitivity and glucose control. In addition to improving insulin sensitivity, regular exercise can decrease blood sugar, cholesterol, weight, blood pressure and has been shown to reverse NAFLD. Exercise also contributes to lower levels of stress and well as inflammation. Chronic stress and inflammation are major players in the development of insulin resistance.

What type of exercise should I be doing?

It appears that there is certain types of exercise that are going to be more effective at increasing sensitivity to insulin, with most studies showing that higher intensity is superior. Higher intensity exercise also appears to result in increased weight loss compared to lower intensity forms of exercise. Some evidence shows greater benefit when exercise is done in a fasted state. The evidence also indicates that a combination of aerobic training and resistance training is better than either alone. The combination of aerobic and resistance styles of training has also been shown to be better at lowering inflammation and better for weight loss. At a minimum we should be getting 30 minutes of moderate-to-vigorous exercise in 3-5 days per week. Sadly, only 30-40% of people are actually meeting this target. With a third of our population already diagnosed with diabetes and pre-diabetes, and even more with insulin resistance, this should be a no brainer.

It is important to note that all forms of exercise has been shown to have some beneficial effect on insulin sensitivity, so the most important take home is to get your body moving each day, however that is possible for you.

Concluding Thoughts

Insulin resistance contributes to a whole host of health issues from cardiovascular disease, and weight loss resistance to mental health and menstrual cycle irregularities. Exercise is one of the many things we can do to begin to increase our sensitivity to insulin to help prevent and treat these conditions. We should be moving our bodies daily in addition to eating a healthy diet, which is the best treatment. If you are unsure if you might be insulin resistance, or wonder if it’s contributing to how you feel, you can get tested long before it progresses to diabetes. It is a reversible condition that can and should be treated.

Resources:

PMID: 28879026
PMID: 32737757