While the most benefits come from exercising 30 minutes or more per day, you can start small. Short, 10-minute bursts of activity can have a positive effect on your mood. You don’t need to train at the gym, sweat buckets, or run mile after mile, either. Even very small activities that get your arms and legs moving can add up over the course of a day. Try incorporating walking, running, swimming, dancing or another rhythmic exercise—that requires moving both your arms and legs—into your daily routine. The key is to pick an activity you enjoy, so you’re more likely to stick with it. Even very small activities can add up over the course of a day.