This summer, I've gone to the gym six days a week, sometimes seven. What's my secret to staying motivated?

Hot fitness instructors.

I'm seeing several. I'm monogamous in romance but promiscuous with group fitness classes.

I've yet to meet an ugly trainer. Phenomenal physical shape is a given, and in New York, most also work in acting, dancing, and other professionally attractive jobs.

Thank goodness I'm a writer.

My first fitness love was Edu. He was head-to-toe gorgeous, with muscles like a superhero.

I had to let him measure my body-fat percentage with pincers on my belly, which took superhuman humility.

I wish we could've worked out with the lights off.

Stunning fitness professionals come in every flavor, and I'm determined to taste them all.

Gregg is my sexy drill sergeant: buzz cut, square jaw, V-torso, not a bad angle on him. He teaches a class called "Whipped" that I only wish was literal.

Philippe is the spin instructor who makes me dizzy. He's a green-eyed pretty boy, perfectly buff, tan, and hairless, like he was born Photoshopped.

There are always several women loitering after class to ask Philippe a pretend question. It's pathetic.

Especially when someone steals my pretend question.

I'm equally enamored with the women. Story teaches a strength class and looks like Barbie with better delts.

But Aida is my main fitness crush object. A bohemian gypsy in leg warmers, she teaches Pilates with a Spanish accent. Imagine strengthening your core with Penélope Cruz.

For the first month of class, I thought she was telling us to "excel," which I found encouraging. Then I understood we were to "exhale."

For Aida, I can only sigh.

Have you noticed their unusual names? These are names befitting the gods and goddesses. My gym is Mount Olympus, with a monthly fee.

We are but their mortal playthings. They control our heart rate: How's that for playing God?

I'm happy to do their bidding. A simple, "That's eet!" from Aida can make my day. I want to impress her so badly, I bought a book, Anatomy of Pilates, to cram for class.

I'm such a nerd, I can't even be a jock without studying.

I feel an instant sense of camaraderie with the other class members, and I'm fiercely loyal to my favorite instructors.

I think I could be very susceptible to a cult.

My loyalty was tested last week, when a girl disrupted our Pilates class by packing up early. Aida asked if she could wait, "Please, eet ees only five minutes."

The girl muttered, loud enough for everyone to hear it. "Bitch."

I gasped, expecting lightning to strike.

"Excuse me, what ees your name?" Aida's voice was as sweet as crema Catalana, but everyone knew she could break this chick in half.

The girl wisely fled. She'd better hope she never runs into me in the locker room.

Yet, all great love stories end in sorrow. I learned yesterday that Aida is leaving me. She's moving to Los Angeles.

My heartbreak is as operatic as her name. Verdi had it right: I want to lock us in a pyramid and do mat Pilates with her until death do us part.

But I'm grateful. Saint Aida performed two miracles in my life. First, she made me like my stomach, a body part I've hated since 1999. Second, she made me feel powerful after a period when I'd felt my most helpless.

In March, I broke up with my boyfriend five days before my grandmother got sick. By the time I returned to New York after her passing, I was 15 pounds heavier on the scale and about a hundred pounds heavier in my heart. In helping me rebuild my body, these instructors reminded me that I'm capable of improvement, adaptation, and strength.

Aida taught me that even when you're flat on your back, you can pull yourself up. One vertebra at a time.

Look for Lisa Scottoline and Francesca Serritella's new collection of humor essays, "Have a Nice Guilt Trip," in stores now. Also, look for Lisa's new novel, "Keep Quiet."