Feeling smug when you clock 10,000 steps each day? Not so fast: While that target has widely been hailed as a goal to beat cardiovascular disease, a new study suggests upping it to 15,000 steps. UK researchers who studied 111 postal workers in Glasgow found profound differences in the health markers for those who were on their feet the longest each day, the New York Times reports. Some of the workers, who were mostly aged 40 to 60, sat for 15 hours or more daily at office jobs and at home, and others were mail carriers who walked their routes. The volunteers wore an activity monitor for a week, at work and off duty, that measured how many steps each took and how much time they spent seated. Writing in the International Journal of Obesity, the scientists reported that those who walked at least 15,000 steps each day, or about seven miles, showed no increased risk of heart disease.
Those who moved the most had normal waistlines and BMIs, but any amount of walking or even standing shrank a worker's waistline and risk of cardiovascular disease. For the sedentary workers, the picture was the opposite. After five hours of sitting a day, each additional hour in the chair boosted their chance of developing heart disease by .2%. The results highlight the importance of moving around—a lot. For 15,000 steps, that means walking for two hours at a very brisk pace of 4mph, lead author Dr. William Tigbe tells the Times. He suggests tackling that target "in bits" by doing 30-minute walks a couple of times a day, with shorter walks in between. "Our metabolism," he says, "is not well-suited to sitting down all the time." (There's a new daily recommendation for fruits and veggies.)