Fitness professionals are naturally keen to share our love of fitness with our members. Members have paid good money to be in a club; we are duty-bound to share with them the benefit of our years of experience and expertise by getting them in the best shape possible.

Unfortunately, the initial zeal of a new member is sometimes lost in the first few weeks for members who, with minimal guidance, have given their all in their first few fitness classes only to find they cannot move for a week afterwards. By the time they are able to walk without wincing again, their momentum is gone, sometimes for good.

Quantifiable scientific research shows that a gradual start is better. In research conducted last year in association with Pennsylvania State University, we found a group of 25 “couch potatoes”—adults who didn’t do a lick of exercise—and prescribed for them 30 weeks of group fitness classes. Group fitness classes were chosen because they offer the elements most people like: music, community and a heck of a lot of fun.

The study allowed these subjects to dip their toes into a variety of group exercise classes—classes that emphasized a cardio workout, some that targeted strength and others that promoted flexibility. The first six weeks acclimatized participants to incorporating group exercise into their daily lives by allowing them to do just 20 minutes of their chosen class, with the duration ramping up steadily but manageably after that. Most importantly, participants were allowed to continue eating as they had done all along with no dietary restrictions.

The results were a 6 percent decrease in body fat across the group of 25 (some of whom, it should be remembered, were likely eating junk food and drinking soda throughout). LDL cholesterol readings dropped by 10 percent, trunk fat and triglycerides took a dive, and pelvic bone density and cardiovascular fitness all increased dramatically.

None of these results is all that surprising to fitness advocates. What might be more interesting, however, is that attendance in the study clocked in at almost 99 percent during the 30 weeks. Most of the study subjects continue with group fitness to this day. Slowly and steadily is the way we now know is best if the goal of a club is to lock customers into their memberships with enthusiasm and motivation.

Club managers and staff can ensure they replicate these results with their own members by first managing group exercise properly. New members should have someone work with them to guide them through the schedule of classes, pointing out what would suit them and perhaps even attending with the member and letting them know it is OK to leave the class if they have had enough. We call this “managed acclimatization.”

With the right management and range of classes, group fitness can reach beyond female members and win males over, too. (Men often think group exercise is not hard enough for them.) Our solution for wooing male members to group fitness? Short, 30-minute, high-intensity interval training that is not for wimps.

The group exercise category has expanded to include a large menu of group fitness and small team training options that add another way to build enthusiasm. The mixing and matching of different classes alleviates boredom and keeps members challenged.

Most of all, club members must find enjoyment in group exercise, which will keep them coming back—what researchers call “compliance”—and enhance the sense of community. These factors are critically important in their choice of where to spend their fitness dollars.

As gym owners, we need to ensure we better “sweat” our assets, wringing every ounce of enjoyment from them for members and keeping them coming back for more.

Phillip Mills is the founder of Les Mills International, which offers professional group exercise. Millions of people every week attend Les Mills classes such as BODYPUMP (weight training) and the new LES MILLS GRIT Series (30-minute high-intensity interval training). The 13 Les Mills workouts are offered in more than 15,000 clubs and led by 90,000 trained and certified instructors. Les Mills renews each exercise-to-music program every three months with new choreography, licensed music and instructor education.