Everyone knows that exercise is good for the body. But there is a growing awareness among researchers and fitness professionals that working out in groups can provide additional benefits for some. A March 2008 study in the journal Birth by University of Taiwan researchers reported that Taiwanese women taking part in an exercise support program were less likely to have postpartum depression than those who did not. An Ohio State University study reported in the June 2007 Journal of Cancer Survivorship found that group exercise programs improved the physical and psychological well-being of women being treated for early-stage breast cancer. These studies point to specific individuals -- but anyone interested in working out with others can reap rewards. It is difficult to ascertain whether the benefits of group exercise are derived from the activity or the social interaction, but experts agree that the support, variety and motivation a group provides can help improve physical and mental health and create lasting exercise routines. "It is known that women tend to exercise more when they perceive high levels of social support in their lives," says Cherilyn Hultquist, assistant professor in the department of health, physical education and sport science at Kennesaw State University in Kennesaw, Ga. "Seeing familiar faces each class makes it more than a stale exercise environment. It becomes a community with common goals." Social interaction in group exercise settings can be a vehicle of encouragement and motivation for many, says Cedric Bryant, chief science officer for the American Council on Exercise, a nonprofit organization that promotes physical fitness and creates certification programs for fitness professionals. Group classes also create an atmosphere of accountability. "Individuals are more inclined to come to the session because of social interaction, but also to put forth better effort because of the group dynamic that occurs with others -- a positive competition, in a sense," Bryant says. Another advantage to working out with a group is the addition of an instructor. "Many people enter a fitness facility and bounce around on equipment with little thought or direction about their workout," Hultquist says. "This lack of balance can lead to injury, boredom or can limit results." By having a trained professional lead a group, participants receive the full workout experience, including warm-up, workout, cool-downand stretching. A group can also reduce the cost for individuals who are looking for a personal training experience but can't afford one-on-one instruction. Group workouts are no longer being confined to glassed-off boxes inside fitness clubs. Activities can be found for almost anyone looking for something to do -- including new-mother stroller groups, boot camps at local parks, beach-front yoga and cha-cha classes at recreational centers. Though traditional aerobics classes are still popular, new social activity groups like these are becoming increasingly in vogue, according to the 2008 Fitness Programs and Equipment Survey released by IDEA, an association of fitness professionals. Forty-three percent of member respondents said they offer social classes at their facilities, and 67% said they expect growth in this area. Other stats from the survey: From 2000 to 2008, the number of IDEA members offering group strength training increased by 13%; overall, small-group class offerings (those with eight people or fewer) rose 14%. Eighty-three percent of facilities now offer personal training in groups of two, and 58% offer it in groups of three to five (an increase from 44% in 2007). "Those are good numbers and are growing," says Kathie Davis, IDEA's executive director. There is no consumer clearinghouse for finding social activity groups or personal trainers willing to work with more than one person -- but the Internet can be a helpful tool. Websites such as those for ACE or IDEA often have useful information on local groups. And just typing in a city name and a class such as "Stroller Strides" or "boot camp" should net a sizable list. Individuals can also call their local health club or YMCA to find classes or a personal trainer. Beyond that, communities have running clubs that offer group training and many malls have walking programs for the public. Hultquist also recommends inquiring at local churches and recreation centers for community programs or at the workplace for lunch-hour classes. Individuals looking to form their own group can network with their work colleagues, neighbors, family and friends to try and find matches with their interests, fitness levels and goals. Regardless of where you find a group, do due diligence before joining. Make sure an independent trainer has proper credentials and that you are comfortable working with him or her. Bryant recommends that you check with the Better Business Bureau (welcome.bbb.org) when considering a group that is part of an organization that's unfamiliar to you. And before signing up, and paying, for a group of new classes, Davis says to start with one session and see if you like the group and instructor or trainer -- and feel that the workout is right for you. Exercising in a group setting may not be a good fit for everyone. And those who choose it must remember the most important thing: to select an activity they enjoy. "The goal is to acquire a new positive habit: exercise," Bryant says. "Research clearly shows that if you find something you deem enjoyable, you will stick with it."