One extra minute of extra brisk activity can make nearly half a pound difference to the average woman's weight, research has shown.
Scientists tested the activity levels of more than 4,500 men and women and discovered that when it comes to weight loss, every minute counts.
Numerous short bouts of heart and lung-working activity, such as taking the stairs instead of a lift, had the same effect as less frequent longer exercise periods.
The research was carried out by attaching accelerometers to the volunteers, devices which measure movement and activity.
In the US, current guidelines advise people to get at least 150 minutes of moderate-to-vigorous activity per week, which can be accumulated in eight to 10 minute periods.
"What we learned is that for preventing weight gain, the intensity of the activity matters more than duration," said Jessie Fan, professor of family and consumer studies at the University of Utah.
"This new understanding is important because fewer than 5% of American adults today achieve the recommended level of physical activity in a week according to the current physical activity guidelines.
"Knowing that even short bouts of 'brisk' activity can add up to a positive effect is an encouraging message for promoting better health."
The study found that, for women, each daily minute spent in higher-intensity short bouts of activity was associated with a Body Mass Index (BMI) reduction of 0.07.
BMI is calculated by dividing a person's weight in pounds by their height in feet squared.
Every briskly active minute offset the calorie equivalent of 0.41lb, according to the researchers.
Comparing two women of 5ft 5in, the one who regularly adds a minute of brisk activity to her day will weigh nearly half a pound less, they said.
Results were similar for men. Each daily minute of higher-intensity activity lowered the likelihood of being obese by 2% for men and 5% for women.
The findings appear in the latest edition of the American Journal of Health Promotion.