WASHINGTON – We might be cutting that run a little short and not owning up to it.

In a weeklong study, researchers in Norway had people report on their own physical activity. Those taking part in the study were also given sensors to measure their actual movements.

Men reported they had spent 20 minutes on vigorous exercise and women reported 12 minutes. But in each case, they had done less than three minutes worth.

Men and women also overstated the time they spent on moderate exercise, like walking, by more than 50 minutes.