They found that people who walked at a faster pace for at least 15 minutes a day had a lower risk of dying during the study period than those who walked more slowly. Both groups lowered their risk of death during that time, but the reduction was more impressive among those who regularly walked at a brisker pace. Read More: Why Walking Isn’t Enough When It Comes to Exercise While those findings may not be entirely surprising, Zheng says the trial focused on a group of people who aren’t typically part of exercise studies. About half of the people in the trial made less than $15,000 a year, and two-thirds of the participants were Black. Studies have documented that these groups “are at high risk of many diseases including diabetes and hypertension,” says Zheng—so the lower mortality rate is especially reassuring, since it represents a relatively low impact and low cost way to improve health. Current government health recommendations advise moderate exercise for at least 30 minutes most days of the week, and Zheng says that his study shows that even 15 minutes a day can provide benefits. That’s good news for people who may currently be sedentary and for whom starting an exercise program can be challenging. “If you walk just 15 minutes a day, which is below the recommended level [of exercise], you still benefit,” he says.