Don’t weigh all day to get your workout in. If you’re hoping to lose weight, the best time to work out is early in the morning, a new study suggests.
The study, published in the journal Obesity, found that moderate to vigorous exercise between 7 a.m. and 9 a.m. is the most opportune time for losing weight.
Researchers at Franklin Pierce University in New Hampshire found that the correlation between exercise and weight loss was strongest early in the morning compared to the middle of the day or evening.
“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,” Professor Rebecca Krukowski, co-director of the Community-Based Health Equity center at the University of Virginia School of Medicine Department of Public Health Sciences, who was not associated with the research, said in a media release.
Past studies have looked at the effects of frequency, intensity, and duration of exercise, but researchers wanted to determine if the time of day has any relevance to the outcome of physical activity.
Researchers also wanted to learn if the current guidelines — from the Physical Activity Guidelines for Americans — of 150 minutes of moderate-intensity physical activity per week had an equal advantage for shedding pounds at any point of the day.
“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,” Dr. Tongyu Ma, assistant professor at the University’s Health Sciences Department, said. “Our study provided a novel tool to explore the diurnal pattern of physical activity and to investigate its impact on health outcomes.”
They looked at the information of 5,285 people using data from the 2003 – 2004 and 2005 – 2006 cycles of the National Health and Nutrition Examination Survey by the Centers for Disease Control and Prevention.
The pattern of physical movement was separated into three categories: morning, mid-day, and evening.
Participants also took part in a self-reported dietary recall, which revealed that those in the morning group had a healthier diet and less daily energy intake per unit of body weight.
Findings showed that those who worked out early in the morning had a lower body mass index (BMI) and waist circumference than the other groups — even though this group was the most sedentary of the three.
The morning group mainly consisted of non-Hispanic white people with a college education or higher and who had never used tobacco or alcohol. This group was also the one with the highest percentage of females, and participants were, overall, 10 to 13 years older than the other two clusters.
However, Krukowski noted that it’s still unknown whether those who consistently exercise in the mornings are “systematically different” in ways not acknowledged in the study than those who exercise later in the day.
“For example, people who exercise regularly in the morning could have more predictable schedules, such as being less likely to be shift workers or less likely to have caregiving responsibilities that impede morning exercise,” she said.
“Predictable schedules could have other advantageous effects on weight that were not measured in this study, such as with sleep length/quality and stress levels,” Krukowski continued. “In addition, the ‘morning larks’ who consistently rise early enough for morning exercise may be biologically different from their ‘night owl’ counterparts.”
