The Class: Piyo on the W Hotel’s WET Deck is a special summer event. The one-hour class begins at 9 a.m. Saturdays and is open to the public.

The Appeal: Brittani Rettig’s “Piyo” class promises a fun and energizing fusion of Pilates and yoga with a stunning view of downtown. I checked out Rettig’s website, and then talked my mom (a Pilates fanatic) into joining me for a girl’s day, and off we went.

The Instructor: Rettig is a Texas native and former captain of the Cornell University women’s basketball team. Her resume includes a number of health and fitness certifications to go along with her undergraduate degree from Cornell and an MBA from Harvard. Dressed in typical yoga/Pilates gear, she led the session from her mat at the front of the group by completing each move with the class. How she managed to physically participate in the class herself while giving verbal instruction is beyond me. I’m always impressed by trainers who clearly practice what they teach.

The Space: The sunny deck surrounding the pool creates an exhilarating space to exercise. Park or valet downstairs, then head up to the 16th floor with your mat, towel, and water.

Who's There: There were 30 to 40 students, mostly women in their 20s, dressed in brightly colored yoga gear. The crowd must have surprised the W’s management because I overheard a man in a suit standing at the back muttering to an employee about moving the deck furniture for future classes to allow more space. “We’ve got the most popular place to do yoga in Dallas,” he said as more people filed onto the deck.

How It Went: We signed in and unrolled our mats on the back row moments before the music began pumping hits by Beyonce, Nelly Furtado, and Drake. Rettig began warming us up with a sun salutation series and a few stretches, then turned up the heat with lunges, kickbacks, chair, and squats — focusing on the lower body for most of the class (it is bikini season, after all). The crowded space kept Rettig from walking around to critique form, but she offered modifications to the more challenging moves while reminding us to breathe and focus on the muscles at work.

Once we exhausted our legs and glutes, we moved on to the upper body and core with push-ups, plank, burpees, and leg lifts before winding down with some deep stretches like pigeon and child’s poses. As the 45-minute class wrapped up, Rettig walked around greeting students and taking pictures like a celebrity while W employees handed out coupons to the Bliss spa ($25 off any service over $100) and Cook Hall ($5 pitchers of mimosas), tempting students to stick around for a mani/pedi and brunch.

The Aftermath: We were both a little wobbly, but a quick brunch and a few mimosas set us up for the day of shopping ahead. The following morning we were both reasonably sore in our hips, glutes, and thighs.

Loved: Strolling through the hotel lobby and lounging by the pool made us feel like we were on vacation. We couldn’t help but stick around after class to take a few selfies against the beautiful skyline.

Hated: Get there early to reserve a good space, or you’ll wind up cramped in the back, and don’t forget an extra cushy mat because the cement can be hard on your knees and feet.

Cost: Free! Save your spending money for the Bliss Spa and mimosas at Cook Hall after class.

Difficulty Level: This is a great class for all skill levels because most moves can be modified to suit your ability, and there are so many people in attendance, it’s easy to keep up with a quick glance at one of your neighbors.

Bottom Line: It’s free, it’s fun, and it’s a great workout. Grab some girlfriends and make a day of it.