'Exercise snacks,' or short bursts of activity, shown to improve fitness and strength

Short bursts of purposeful activity — such as walking around the block or lifting small weights — may be the best way to get in the habit of exercising.

Short bursts of purposeful activity — such as walking around the block or lifting small weights — may be the best way to get in the habit of exercising. Bite-sized bits of exercise also improve heart and muscle fitness, a study published Tuesday in BMJ Sports Medicine found.

Less than half of adults in the United States get enough aerobic activity and less than a quarter get the recommended amount of both aerobic and muscle-strengthening exercise.

“When people are asked why they don’t exercise, the answers are almost always the same, no time and no motivation,” Miguel Ángel Rodríguez, a doctoral student in clinical research at the University of Oviedo in Spain, who led the study, said in an email.

Rodríguez and his team measured how brief bouts of exercise spread throughout the day — which he calls exercise snacks — affected cardiorespiratory and muscular fitness, as well as blood pressure and body composition in adults who did not regularly exercise.

The team compiled data from seven randomized clinical trials that included people ages 18 to 80. There were more than 400 inactive people across the study, about 70% of whom women.