For the new study, data on physical activity was passively gathered from smartphone accelerometers, and participants were also sent a short survey at two random intervals throughout the day which asked questions about their emotional state. Users reported their emotional state on a grid, based on how positive or negative, and how energetic or sleepy, they were feeling. Users were also asked a handful of questions about how their mood compared to normal. The activity data was then averaged over the course of the day, so while the researchers could not pinpoint what participants were doing at any given time, they found that participants who had higher levels of activity throughout the day reported a more positive emotional state. “Our data show that happy people are more active in general,” said the paper’s senior author Dr Jason Rentfrow, from Cambridge’s Department of Psychology and a Fellow of Fitzwilliam College. “However, our analyses also indicated that periods of physical activity led to increased positive mood, regardless of individuals’ baseline happiness. There have been many studies about the positive psychological effects of exercise, but what we’ve found is that in order to be happier, you don’t have to go out and run a marathon – all you’ve really got to do is periodically engage in slight physical activity throughout the day.” “Most of us don’t keep track of all of our movements during the day,” said study co-author Dr Gillian Sandstrom from the Department of Psychology at the University of Essex. “A person might track whether they went for a walk or went to the gym, but when asked, most of them probably wouldn’t remember walking from the desk to the photocopier, or from the car to the office door.” - www.cam.ac.uk