Exercise later in the day may reduce insulin resistance

Image showing a group of people running and training outdoors at nightShare on Pinterest
Exercising in the afternoon or evening is linked to a reduction in insulin resistance, compared to physical activity spread out throughout the day, according to one study. Henrik Sorensen/Getty Images
  • Researchers in Europe analyzed the data to see if breaks in sedentary activity can impact insulin resistance.
  • The researchers included middle-aged participants from the Dutch Obesity Epidemiology Study and examined their liver fat content and insulin resistance in conjunction with physical activity schedule.
  • The researchers found no link between interruptions in sedentary activity and reduced insulin resistance, but did find a possible link between exercise timing and insulin resistance.
  • Although morning exercise does not reduce insulin resistance, researchers have found that afternoon or evening exercise may be beneficial.

According to World Health Organization, obesity rates have tripled worldwide since 1975. The link between obesity and insulin resistance is bidirectional. Insulin resistance often develops due to being overweight or obese, which can lead to type 2 diabetes.

Since type 2 diabetes can be an expensive disease to treat, contribute to many health problems, and even be fatal, researchers are interested in learning more about different ways to improve insulin resistance.

Exercise is an important aspect of health. Previous studies have shown that it can improve insulin resistance. In a new study published in Diabetology (the journal of the European Association for the Study of Diabetes), researchers have found a link between the timing of exercise and insulin resistance.

Beta cells in the pancreas produce insulin, a hormone created by the body and responsible for regulating blood sugar.

Certain medical conditions can impact the body’s ability to produce or respond well to insulin, including type 1 diabetes and type 2 diabetes.

Type 1 diabetes occurs when a person’s body produces little or no insulin. Doctors usually diagnose this form of diabetes earlier in life, and there is no cure.

A person who develops insulin resistance may be diagnosed with type 2 diabetes.

This form of diabetes is more common in middle-aged and older people. Type 2 diabetes is also More widespread in people who are overweight or obese, and they can manage it with medication, diet, and exercise.

Unlike type 1 diabetes, people with type 2 diabetes can go into remission with lifestyle changes in some cases, including substantial weight loss.

The researchers looked at data from the Dutch Obesity Epidemiology Cohort Study, which collected data from 6,671 people aged 45 to 65 between 2008 and 2012.

Some of the data collected included BMI, fasting and post-meal blood glucose and insulin samples, as well as MRI scans from people likely to undergo imaging. Additionally, 955 participants wore activity monitors for 4 days.

In the group that wore activity trackers, the researchers narrowed the group down to 775 participants with an average age of 56. The composition of the group was 42% male and 58% female, with an average BMI of 26.2.

Looking at activity tracker data, the researchers divided the daily periods into three segments: 6:00 a.m. to 12:00 p.m. (morning), 12:00 p.m. to 6:00 p.m. (afternoon); and from 6 p.m. to midnight (evening). They excluded the hours from 12 p.m. to 6 a.m.

For each of the 6-hour periods, the researchers looked at the different levels of activity recorded by the heart rate monitors.

After analyzing the data collected, the researchers did not find a link between breaks in sedentary activity and a decrease in insulin resistance. However, they found an association between insulin resistance and the time of day participants performed moderate to vigorous physical activity, as recorded by activity monitors.

They found no difference in MVPA and a reduction in insulin resistance in the morning segment of the data.

The researchers also looked at liver fat captured in MRI scans and noted that the number of breaks in sedentary time did not impact liver fat content.

“Further studies should assess whether the timing of physical activity is indeed important for the onset of type 2 diabetes,” the authors wrote.

Dr Michael SagnerPresident of the European Society for Preventive Medicine, spoke with Medical News Today on the results of the study.

“It is certainly timely to study the chronobiological effects of exercise,” Dr. Sagner said. “The timing of exercise is a relatively unexplored area in human studies and requires further study.”

Dr Sagner noted a weakness of the study being the limited 4-day window during which participants were monitored and said further research was needed “whether certain types of activities provide more health benefits when performed at specific times of the day”.

“The present study cannot lead to changes in the current recommendations. Physical activity is essential for health and disease prevention and should be incorporated into the weekly routine, however timed throughout the day.

– Dr. Michael Sagner

Dr. Ishita Patel, a Texas Diabetes and Endocrinology board-certified endocrinologist, also spoke with DTM about the study. Dr. Patel also believed that the timing of exercise to reduce insulin resistance needed more research.

“The study data analyzed took place over a short period of time – four days,” Dr. Patel pointed out. “It would be interesting to assess liver fat and insulin resistance over an extended period of time, and also [its] relevance for populations of concern – such as pre-diabetics and diabetics.

As Dr. Sagner also mentioned, Dr. Patel thought the important thing about exercise was to make it part of the routine rather than focusing on the moment.

“The vast majority of people are so busy that it’s hard to find time to exercise regularly. In the same way that we advise on diet, I think consistency with exercise should be encouraged rather than adding the added challenge of finding “the perfect time” to exercise.”

– Dr. Ishita Patel

Leave a Comment