Most of us struggle to find time to exercise. For some people, it’s easier to do short workouts most days of the week, while others prefer longer workouts once or twice a week, such as on the weekends. A new study suggests that at least for muscle building, one way to work out might be better than the other. In the study, published in the Scandinavian Journal of Medicine and Science in Sports, researchers had one group of participants perform a single set of six resistance exercises, performed each weekday. The other group performed 30 sets during a single weekly session. They observed that participants who performed smaller amounts of weight or resistance training five days a week improved muscle strength and size more than a single longer weekly weight training session.