Exercising between 7am and 9am may be key for weight management, suggests study

Exercising between 7am and 9am may be the key to weight management, new research suggests.

Although evidence regarding the optimal timing of physical activity has been controversial, a new study has found the start of the day appears to be the best time to enhance the link between daily moderate to vigorous physical activity and obesity.

The  findings revealed a strong association between moderate to vigorous physical activity measured as 1,952 or more counts per minute on an accelerometer – which tracks movement similar to a pedometer – and obesity in the morning group.

There was a weaker connection in the midday and evening groups.

People who met the physical activity guidelines – 150 minutes of moderate-to-vigorous physical activity – in the morning group had a lower body mass index and smaller waists than those in the other groups.

Tongyu Ma, assistant professor, Health Sciences Department, Franklin Pierce University, and the Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, said: “Our study provided a novel tool to explore the diurnal pattern of physical activity and to investigate its impact on health outcomes.”

Clinical psychologist Rebecca Krukowski, professor and co-director of the Community-Based Health Equity centre, University of Virginia, School of Medicine, who was not involved in the study, said: “This is exciting new research that is consistent with a common tip for meeting exercise goals – that is, schedule exercise in the morning before emails, phone calls or meetings that might distract you.”

People in the morning group also reported having healthier diets and consuming fewer calories per unit of body weight compared with people who exercised later in the day.

According to the findings, people in the morning group also spent a significantly higher amount of time sitting or lying down – not moving – than the others.

But the researchers found that despite this, the lower body mass index and waist size in the morning group persisted.

Researchers used data from the 2003–2004 and 2005–2006 cycles of the National Health and Nutrition Examination Survey by the Centres for Disease Control and Prevention in the USA.

A total of 5,285 people were included and split into morning, midday and evening exercisers.

Those in the morning group (642 people) were 10 to 13 years older than the two other groups.

This cluster also had the highest percentage of women, and the majority of them were primarily non-Hispanic white, had a college or higher education, and had never used tobacco or alcohol.

“Our findings propose that the diurnal pattern of moderate to vigorous physical activity could be another important dimension to describe the complexity of human movement,” Assistant Professor Ma said.

The findings are published in Obesity, The Obesity Society’s (TOS) journal.