Changing the world should not tap you dry. Here’s how to keep your proverbial cup full so you can be the best possible champion for your cause.

Give Warmth
Charitable donations are great, but a simple kindness can elicit the “helper’s high” that’s linked to altruism, say psychologists from the University of Buffalo. When you show tenderness—by putting an arm around a friend who’s struggling, for example, or petting a lonely shelter animal—the compassionate feelings you experience lower stress hormones and boost relaxation hormones. And the feel-good buzz you gain from one minute can be stronger than from hours of a charitable act that doesn’t involve building social connection.

Rethink Your Role
Everyone gets disillusioned occasionally—by annoying coworkers, hairy logistics and other workplace challenges. To boost morale, focus on your higher goals. In a Canadian study of health care employees, people who were able to find meaning and purpose in their mission were healthier, happier and more productive. Ask yourself: How is my work making a difference?

Celebrate Small Wins
The fight against problems like logging, bullying and pollution are so enormous that they can sometimes seem unwinnable. That’s why it’s so critical, according to Harvard researchers, to track, reflect on, and celebrate not just our major achievements, but also our seemingly minor ones, like simply learning what doesn’t work. (Hey, that’s progress!) Make it a goal to record three small wins a day—using an app like Evernote or that cool suede notebook from India—and let the positive energy flow.

Find the Door
For an energizing mood boost, skip the coffee break and head outside. A huge body of research shows that being out in nature makes people feel alive. According to a study in the Journal of Environmental Psychology, just 20 minutes of greenery and fresh air are like fuel for the soul. If you’re not near a park, a garden or even a tree, just bask in the sunlight to start feeling sunnier.