Teen uses Twitter to compliment peers

>>> back now at 7:44. a lot of folks are hitting the gym, trying to make good on new year's resolutions trying to lose weight but few fitness centers are like the one janet shamlian found in dallas. good morning to you.

>> reporter: good morning. it looks like every other gym this time of day, very busy, with one big difference. to become a member here, you have to be severely overweight, no exceptions. the people getting a workout in this morning before heading to their jobs are just fine with that. in fact, it's the reason they joined. it's as crowded as every other gym in early january. every hoist of a kettle ball fueled by a new year's resolution. while many athletic clubs have membership requirements, downsize fitness is in a league of its own. to work out here you have to have a lot to lose. members must be at least 50 pounds overweight, just like this trainer was two years ago.

>> it's comfortable. there's nobody looking in. we're all just here together.

>> reporter: unlike most, there are no stare at yourself mirrors here. treadmill belts are wider than normal to accommodate larger bodies. you definitely won't find those spandex-wearing hard bodies that can make the less fit feel like throwing in the towel .

>> it's frustrating. you don't feel like you fit in. and sometimes people are looking at you.

>> reporter: but when she joined downsize fitness at 271 pounds, lauren lost not only inches, but the anxiety she felt exercising elsewhere.

>> it's different here. you get the support. you don't just get the workout.

>> reporter: new members like forest mckinney, who started at 472 pounds, are required to submit a health questionnaire. some must get a doctor's okay. trainers monitor heart rates and classes are adapted to physical limits.

>> i liked it because i knew where everybody else was going to be in my class and that i was going to fit in and not be pushed so hard to compete against people that are more capable than me right now.

>> reporter: for lauren, it finally feels like a recipe for success, even if she stumbled on to the club in the midst of a fast food run.

>> i was late for dinner so i stumbled on to the club driving to chick-fil-a.

>> oh, come on.

>> no, literally, i did.

>> reporter: there are two of these clubs now one in dallas, one in chicago. it's a concept they're hoping they can take elsewhere. people here say they just feel comfortable, it feels good to be around people who are not judging them. if you do end up losing those 50 extra pounds required to join, the answer is you can still be a member of the gym, likely to be an inspiration to those exercising around you. everyone knows that they all started in a similar place.

>> it's very inspiring. janua janet shamlian , a great story. thank you so much.