She's finding lots of fans with her high-heel workout.
"The high heels are getting higher and higher and the heels that I have right now," Neilen explained. "I was stumbling around in them, and just figured out a way to make everybody feel comfortable and have fun".
The women warm up with their high heels on for 10 minutes.
Then they change into their sneakers for a grueling 20 minute leg workout.
It's endless repetitions of squats and lunges to strengthen the muscles.
The 55-year-old certified instructor says she uses upbeat music to make the class fun.
"When you are in heels the worst thing you want is to look like you are uncomfortable. If your legs are strong and your core is strong you are just going to feel really good when you are out there in your heels," she said.
Neilen adds that what you eat is crucial to achieving the shape you want.
"Picking your fruits and vegetables making them come from nature. Try and keep it where your products are not in a package," she said. "People don't realize this, but if people go in a grocery store your shopping should consist of the outer perimeter of the grocery store."
Dietary advice and the high heel workout keep her clients happy.
One of them is Glenda Toney.
"I love high heels and I walk in high heels all of the time so it was just a perfect fit for me and I love working out with Rosalind," she said.
Neilen teaches at the Martin Downs Sports Resort and at two of her own studios studios in Martin County.