Feeling fit and confident, I walked into Studio B in the Athletic Center Thursday evening. I work out, I run, and I eat well, so how hard could a one-hour Totally Toned class be?

As it turns out, I need to get it through my thick skull that not all exercise is created equally. In reality, each new workout is training a new part of your body (and can leave you aching and exhausted in the process.)

The class began with instructor Danielle Potter, a fifth-year physical therapy student, leading the 15 or so participants in reps of jumping jacks and other aerobically inclined warm-ups.

“My whole philosophy with this class is to do cardio and strength training with a little bit of circuit training intertwined throughout,” Potter said.

I could do this, I thought. This was child’s play, and I was strong as an ox. My confidence was short-lived once we moved onto weights, however. The bicep squeezes and tricep pushes to the pumped-up beats of DJ Khaled had me sweating.

My arms felt great at first, and the fact that we were squatting the whole time made my thighs feel like stone. But after a few minutes of this, my mind started a replay of “you’ve gotta be kidding me,” and continued to do so with every new move.

“It was a really good workout,” freshman Nicole Bertaux said. “My arms are killing me, and it definitely pushed you. I’m doing yoga after, so I hope I don’t die. But I’m looking forward to getting relaxed.”

Half an hour into the workout, I was pretty sure I had lost my ability to squat. Five minutes later, Potter told the class there would only be one more circuit before a water break. She was met with incredulous stares. At 45 minutes, another member of the class looked at me with wide eyes and mouthed, “my whole body hurts.”

Freshman Alyssa Ramos, an athletic training major, said that “it was an intense, fun and motivating class.”

This class was tough. I was dripping with sweat, and the combination of abs, arms and leg workouts has made the task of sitting down painful ever since. Yet, that’s a wonderful feeling in a sense.

“I loved this class,” Chelsea Morin, a junior Spanish and elementary education major, said.  “I’ll probably hate myself tomorrow, but not enough to not come back.”

Totally Toned is in AC Studio B Wednesdays from 6:15 to 7:15 p.m., and Thursdays from 5 to 6 p.m.