Minute-by-Minute for Weight Loss

Physical activity of any duration each day helped shed pounds

(RxWiki News) Ten minutes doesn’t seem like much time to exercise. But if that’s all you have, it can still help with weight loss in the long run.

People who did short bursts of less than 10 minutes of high intensity physical activity a day lost about as much weight as those who did longer bouts of low intensity activity each day, a recent study found.

Every minute of physical activity counts, according to this study's authors. They said their findings show that brief and brisk bouts of activity help with weight loss just as much as longer durations of activity.

"Opt for the extra activity or longer walk."

This study, led by Jessie Fan, PhD, professor in the Department of Family and Consumer Studies at the University of Utah, looked at whether 10-minute bouts of moderate to vigorous physical activity was effective at helping people lose weight.

The study included 4,511 adults who participated in the 2003-2006 National Health and Nutrition Examination Survey, which assesses the health and nutritional status of children and adults across the US.

Participants wore an accelerometer on their hip for seven consecutive days to measure the number of minutes they spent each day doing different levels of physical activity. Participants who used wheelchairs or were unable to walk were not given an accelerometer.

Long bouts of high intensity physical activity were categorized as doing more than 2,020 accelerometer counts per minute for at least 10 minutes. Short bouts of high intensity physical activity consisted of the same number of accelerometer counts for less than 10 minutes.

Low intensity bouts consisted of 760 to 2,019 counts per minute. These bouts were also categorized as long or short in duration.

Each of the participants had their body mass index (BMI) measured throughout the course of the study. BMI is a measure of height and weight calculated together that tells whether someone is a healthy weight, overweight or obese.

Both short and long bouts of high-intensity physical activity were tied to weight loss over time, the researchers found. BMI and the risk of being overweight or obese both decreased.

As long as exercise intensity exceeded 2,020 accelerometer counts per minute, the researchers found it did not matter how long people exercised to lose weight and lower their BMI. Both men and women lost similar proportions of weight.

Although the recommended amount of physical activity is 150 minutes per week, men did an average of 61 minutes of higher-intensity long bout physical activity per week and women engaged an average of 46 minutes of higher-intensity long bout physical activity each week.

Most of the participants’ physical activity minutes were accumulated while doing lower-intensity short bouts followed by higher-intensity short bouts.

“If done on a regular basis, such moderate to vigorous physical activities are consistent with lower BMI,” the researchers wrote in their report. “Although long durations of exercise are beneficial to health, our results show that brief and brisk bouts are just as beneficial to BMI.”

The body is built to adapt to the stress that is placed on it, according to Jim Crowell, head trainer and co-owner of Integrated Fitness and dailyRx Contributing Expert.

Crowell said that only doing low intensity workouts isn't as effective at creating that "athletic" look simply because the body has no reason to adapt with that level of intensity.

“I do like to mix our workouts up a lot but a staple of our workout program is a shorter time but high intensity workout and it has proven to be very successful for us since our inception!” Crowell said of Integrated Fitness.

The researchers noted that they could not determine whether exercise by itself was the sole cause of participants’ weight loss in their study. The researchers did not track other factors that typically affect weight loss, including diet and family genetics.

In addition, the researchers were not able to track activities that could not be measured using an accelerometer and how those activities affected weight loss.

This study, which was funded by the National Institutes of Health, appears online in the American Journal of Health Promotion.

Review Date: 
August 6, 2013