Ultimate Ab Workout - LEAD
Credit: Courtesy

I own twice as many sports bras as I do regular bras. My ideal happy hour involves cardio rather than cocktails, and I never leave home without a pair of gym shoes in my bag just in case the mood strikes to hop into a fitness class while I’m floating around the city. Needless to say, I love working out.

Bonus: being in my role here at InStyle means I get to try a lot of different workouts as studios open around town, which means I rarely commit to the same workout for an extended period of time. Or that was the case, rather, until I found SLT.

Blend muscle-lengthening yoga moves with core-toning Pilates principles and you get the full body-sculpting workout known as Strengthen Lengthen Tone. It’s basically a hyped up Pilates class done on a calorie-torching Megaformer machine, and it's one of the most challenging 50-minute sessions you can find.

Since I started taking class (I’ve been a twice-a-weeker for well over a year now) I’ve seen my body transform unlike any other workout I’ve done (and trust me, I've tried them all). Nothing has worked as well to create a seriously defined core (among other things, including glutes of steel) than regular visits to this hotspot (no wonder that Sofia Vergara, Jamie Chung, and Nina Agdal are regulars. I once took class right next to Karlie Kloss.)

VIDEO: How to Get a Body Like Sofia Vergara

Although it was clear that my body was changing, I was curious as to why this workout was so much more effective than anything else I’ve tried. “SLT is so effective because it combines the principles of cardio, Pilates and strength training into a revolutionary workout,” SLT founder Amanda Freeman tells me after I pepper her with questions to help me understand the magic. “The workout on the Megaformer allows you to target muscles so specifically and work them until muscle fatigue. And there are a wide variety of moves, so your body is constantly challenged. “

But like most good things in life, it doesn’t come easy. The first time I took class, I could barely hold a plank. My muscles were shaking beyond control. I was next-day sore before I even got off the machine. Afterwards, I couldn’t walk up stairs for days. Now, I can pike up and down the machine like a pro, and I have the core to prove it. I don’t always break a sweat during class (which in the past was always my gauge for how hard I was working; I hated not sweating during a workout) yet every time I take class, I’m still incredibly sore afterwards, further proving that this workout is still changing my body.

Why is it such a good ab definer? “Thanks to the Megaformer machine, our clients are forced to engage their core nearly the entire 50-minutes of a class,” Freeman says. “The variety of moves that are performed in a class target your abs from all angles in ways no other workout can. You will feel your abs engage and work in specific and unique ways throughout a session.”

Will I continue my long-term relationship with SLT? Obvi (even though my bank account feels the pain from it). Will I continue to try out workouts all over the city to fuel my passion for breaking a sweat? Absolutely. Will I continue to buy sports bras with my paycheck instead of regular bras? You better believe it.

Learn more about SLT ($40 per class, several packages available) at