On command, they hop on the stationary cycles, working in the dark to the rhythm of fun videos and pulsating music.
When the lights come on, it's time to slip on the boxing gloves and pound the bags, mixing in weights, lunges, squats, leg lifts, crunches, pushups, the dreaded burpees, isometrics and an occasional outdoor sprint.
When Epic Boxing and Fitness opened its new location nearly eight months ago, Westchase area residents were introduced to a new kind of workout.
Interval training, three minutes of action followed by 30 seconds of rest.
Three rounds of spinning, nine rounds of boxing.
"I love it,'' said Tracy Michael, a math teacher at Countryside High School who completes each weekday with a Spoxing workout. "The hour goes by so fast. You're working so hard, sweating so much. You don't stop because she won't let you. You always give your best effort because she might be looking.''
She is Esther Solano, the all-seeing trainer, the inventor of Spoxing. Solano, a force of nature, is the co-founder of Epic Boxing with business partner Jaye Maddon, wife of Chicago Cubs manager and former Tampa Bay Rays manager Joe Maddon.
Solano said Spoxing workouts, recently featured in Men's Health magazine, are effective for all shapes and sizes.
"They are for everyone,'' she said.
And Solano should know. Her story is a slice of everyone.
Solano said she has struggled with weight and self-esteem issues. Nearly five years ago, following a late-term miscarriage that coincided with an abusive relationship, her weight approached 400 pounds. Medication caused her hormones "to go crazy.'' She battled depression and despair.
Some nights, when there seemed no way out, she locked herself in a room, chanting over and over a favorite part of Scripture, Jeremiah 29:11.
For I know the plans I have for you, plans to prosper you and not to harm you, plans to give you hope and a future.
Solano already believed in boxing workouts. She had been a client, then became a trainer, either with a gym, conducting group boot camp sessions or going to someone's home for one-on-one training. The needs of her own body, though, were overmatched by a tumultuous personal life.
"As I was making them skinny, I was getting fat,'' Solano said.
But her long-term clients, mostly affluent professionals, understood the impact of the gathering storms in her life. They stayed loyal. They tried to help, and Solano soon helped herself with a sensible diet and strict workouts. She was dropping weight, feeling better and kept getting client referrals.
One of them was Jaye Maddon, who had just moved to Tampa full time and sought a personal trainer.
"I felt Esther exuded a lot of confidence and strength, not only physically, but emotionally,'' Maddon said. "She told me immediately she had been battling weight issues most of her life. Whenever I see a personal trainer or coach who has the same issues as me, I immediately feel comfortable. I know they can identify with me.
"When she trained me, she didn't let up because I was having a bad day or didn't want to do the workouts. She was just a real person and we hit it off. She was just real. And we discovered we had a lot of the same goals.''
One of them was opening a boxing workout facility.
Maddon loved Solano's concept of combining spinning and boxing. They began a partnership and opened their first Epic facility in South Tampa three years ago.
Last year, seeking to expand, they fell in love with an existing boxing facility in Westchase, eventually purchasing it from Punch Boxing and opening the second Epic as 2016 began. Popular trainer Martin Vergara, an up-and-coming mixed martial arts fighter, remained at the Westchase facility and adapted to the Spoxing format.
There are long-term plans to franchise the Spoxing/Epic concept, probably to other Florida locations and maybe even to Chicago, where Joe Maddon serves as one of Epic's biggest cheerleaders.
Last year, an introductory event was staged by Gate F of Wrigley Field. Spinning cycles and boxing bags were set up near Wrigley's iconic marquee. As workouts commenced, Solano noticed that Cubs owner Tom Ricketts was standing nearby, enjoying the proceedings.
Joe Maddon delivers the Epic message when he can. Last month, Chicago White Sox outfielder Melky Cabrera, who trains with Solano during the offseason, leaped high to rob a home run off the bat of Cubs slugger Kris Bryant. In his postgame news conference, Joe Maddon threatened to "revoke Melky's Epic Boxing membership'' because he said the player's added strength and agility allowed him to make the catch, featured as ESPN's top play.
"I think Spoxing is something different, it's something sustainable and it appeals to the true gym rat,'' Joe Maddon said by telephone from Chicago. "I'm happy to be associated with it, but look, it's all Jaye and Esther. They have made this happen.
"You could call them an unlikely pair. Jaye is from the quiet part of the world and Esther is more from the boisterous. I mean, that girl Esther, she's a ball of fire. There's no sugar-coating anything. But it's one heck of a partnership if you ask me. These two ladies have started something very dynamic, and it could get really big.''
Solano compared their partnership to a "Thelma and Louise situation,'' where both women enjoy the planning, fellowship and problem-solving with a sense of adventure and lots of laughter.
"We think Spoxing is one of the coolest hybrids around,'' Solano said. "We've combined two of the hardest workouts. It mirrors a professional boxing match and boxers have been proven to be some of the best athletes around.
"For me, it's a very easy thing to talk about and promote. I believe in it. It has literally changed my life. And I think it's going to change a lot of other lives, too.''
At the Westchase facility, when the lights go out and the music-driven spinning begins, it happens one hour at a time.
"Esther is going to force you out of your comfort zone and everybody needs that,'' said Epic regular A.J. Jones, who works in shipping and receiving. "These workouts clear out my mind. They are therapeutic. I look forward to them every single day.''
Contact Joey Johnston at email@example.com.