High intensity physical activity in sessions less than 10 minutes can be as effective for losing weight as lower intensity exercise over a longer period of time….
In a study published in the American Journal of Health Promotion, participants who engaged in short yet intense physical activity experienced similar weight loss to those who took part in low intense activities for a longer period of time.
The purpose of the study led by Jessica Fan, PhD, was to determine if 10 minutes or less worth of moderate to vigorous physical activity was enough to help individuals shed some weight.
Participants of the study were recruited from the 2003-2006 National Health and Nutrition Examination Survey, a survey that analyzes the "health and nutritional status of children and adults across the US." A total of 4,511 adults who took part in the survey also took part in the study. The participants who were able to walk were given an accelerometer to attach to their hip for the duration of 1 week. This device measured the amount of time spent doing different levels of activity.
High intensity physical activity for an extended period of time was classified as greater than 2,020 accelerometer counts per minute for at least 10 minutes. Short but high intensity physical activity also consisted of 2,020 accelerometer counts per minute, but for less than 10 minutes. Furthermore, whether for a long or short duration of time, low intensity physical activity was associated with 760 to 2,019 counts per minute.
Participants also had their body mass index (BMI) measured throughout the study to determine if they were at a healthy weight in consideration to their height. Researchers then tied their weight to the type of physical activity they were engaging in (high vs. low intensity in short vs. long periods) to see in which situation they were losing the most weight. It was found that as long as participants exceeded 2,020 accelerometer counts per minute, regardless of the duration of physical activity, weight loss occurred in similar proportions among men and women. BMI also decreased similarly among these individuals.
This study demonstrates that the recommended 150 minutes of physical activity per week is not necessarily needed to manage one’s weight. The researchers concluded their study by saying, "Although long durations of exercise are beneficial to health, our results show that brief and brisk bouts are just as beneficial to BMI" as long as it’s done on a regular basis.
Limitations of this study included that 1) participants were not monitored for their diet throughout the trial period and 2) their family genetics was not assessed, both of which are factors that affect weight loss.
Fan JX, Brown BB, Hanson H, Kowaleski-Jones L, Smith KR, Zick CD. Moderate to Vigorous Physical Activity and Weight Outcomes: Does Every Minute Count? American Journal of Health Promotion In-Press. 2013.