By day, Jennifer Fucci works full time finding new hires for Bright Horizons' busy home office. By night and weekend, she volunteers with children in a residential treatment program and raises money for organizations like Project Bread, the Juvenile Diabetes Research Foundation, and her family's own Holding Hopes. The after-five-o'clock work might seem wearing getting in the way of, say, sleep but the senior corporate recruiter assures it's anything but. All the time spent with people in need, she says, is actually rejuvenating. "I get so much out of it," says Ms. Fucci enthusiastically. "It's such a great way to spend my time." While the idea of adding extra hours to an already packed week may seem counterintuitive, it's exactly what more and more professionals like Ms. Fucci are doing.  Despite demanding work lives, legions of full-time employees are taking to after-hours volunteering as just the thing to boost their psyches. In 2011, the Bureau of Labor Statistics reported that nearly a third of the nation's working population more than 150 million people donated time outside their places of employment, working gratis as literacy teachers, elder aids, local farmhands!and more. Feel-Good Effect   What's the benefit? Good vibes, for one. "I am so proud that we can make a difference in our communities," says Linda Bartleson, a Bright Horizons regional manager from Iowa who contributes to myriad organizations. But experts say there are fringe benefits. Volunteers can pick up new skills or find ways to enhance old talents. They also get networking opportunities and even the chance to experience a whole different industry. Plus, the satisfaction from doing good spills over onto family, friends, even employers, prompting a recent Harvard Business Review blogger to call the effects of volunteering more than just karmic. It's "a retention tool, leadership development opportunity, and strategic business initiative," wrote Sylvia Ann Hewlett in her blog. Encouraging Social Responsibility Such effects are magnified if the projects are supported by the employer. For that reason, many employers, including Bright Horizons, are building volunteering into their corporate DNA. Ms. Hewlett cites soup kitchens and library programs as some employer-supported initiatives.  Many organizations synch up projects with National Volunteer Week in April. Bright Horizons has its own nonprofit Bright Horizons Foundation for Children through which employees including Ms. Bartleson help build homeless shelter playrooms called Bright Spaces. Bright Horizons saw firsthand the impact of such community service last fall when the whole organization was invigorated by the 25^thBirthday project that sent employees from around the world to build a Bright Space for the Hunts Point Alliance for Children in the most impoverished zip code in the country. "It was absolutely energizing," says Dan Henry, Bright Horizons' chief human resources officer. Later this month, the foundation and its mission will be the focus of a presentation at the Bright Horizons Client Conference on employee well-being initiatives as crucial, effective foundations for sustainable organizational success. The impetus of any service project, notes Mr. Henry, is of course the service itself. But it's impossible not to notice the other upside. "When employees are energized," he says, "they just work better." Bright Horizons is the leader in work/life supports. If you can't join us March 21-23 at this year's client conference Game On! The Competitive Advantage of Employee Well-Being follow the conversation on Twitter @BHatWork and hashtag #BHconf.