I teach indoor cycling classes at a local studio two to three days a week, where every second of my workout is devoted to hyping other people up, remembering the choreography, and, basically, trying to put on a mini-concert for my riders. So on the other three days of the week when I hit the gym for my own lifting program, I crave solitude and a space where I can focus on myself. Ideally, I can sneak in and out of the gym without ever speaking to another soul.

But last month, I decided to try a different approach to strength training: enlisting a workout buddy. My sister and I are both gym rats, although I’ve always been drawn to the endorphins that cardio gives me while she loves to lift heavy. Since I was in search of someone who would push me, I knew she’d be the perfect partner—but maybe not a willing one. Blame it on our genetics, but she’s also of the mind that solo gym seshes are superior.

So when I pitched once-a-week tandem workouts as a month-long fitness experiment, I figured it would take some convincing. Surprisingly, she only had one stipulation: “Sure, but I get to load your weight.”

I agreed, foolishly thinking she’d forget about her rule once we actually got to the gym.

We stuck to our weekly gym dates religiously, and oftentimes tacked on another day or two. And while I’m not completely renouncing my affection for solo lifting sessions, I did notice a few significant changes, thanks to my new gym-mate.

I lifted way heavier

Even before we started squatting, pressing and curling together, my sister suspected that I wasn’t lifting as much weight as I was capable of. So on our very first foray into partner workouts, she loaded up the hip thrust machine with what she thought I could do. After much grumbling and a few desperate pleas for her to take off a plate, I knocked out three sets of eight reps at a new personal best weight. Then, I PR’ed my Romanian deadlifts, barbell squats, and dumbbell reverse lunges.

(Okay, maybe she was right.)

The best part about hitting these PRs with a partner was that I didn’t have to worry about unknowingly sacrificing my form. I knew she’d call me out if I started to slip. Heck, she would relish it.

Once I knew what it really felt like to max out my weight, I started lifting heavier in my solo workouts, too. Week after week, I surprised myself, and in a shocking twist, I decided to up my weight on an exercise all by myself—no hemming or hawing included.

I was more consistent

One of the most common reasons people recruit a friend in their fitness journey is so that they stay accountable. Nobody wants to be the one who no-shows for that 6 a.m. cycling class you’d promised to go to together. Although I’m usually pretty good about sticking to my three days of lifting, there are times when a long day at the office or my snooze button tempts me to skip. But my sister and I never missed a gym date.

In the spirit of full transparency, there were days I definitely tried to bail. In fact, I almost succumbed to the snooze and missed our very first early morning session. I would have, too, if my new gym-mate didn’t live with me: She performed a spirited version of Gloria Estefan’s “Get on Your Feet” in our kitchen so loud that sleep was virtually impossible.

I still managed to “zen out”

One of the reasons I love working out alone is the opportunity to sit with my thoughts. I find that I do my best problem-solving and emotional inventory when I’m logging miles or lifting something heavy. So I worried that having my sister in tow would mean more chatting and less introspection.

Perhaps it’s because we both value our alone time, but I found that working out with her still allowed for plenty of chances to reflect. Sure we’d joke in between sets or throw out an encouraging one-liner during those shaky final reps, but we didn’t gab so much that I couldn’t find my mental groove.

I gained more confidence in the gym

My sister didn’t just push me to lift heavier. Over the course of the month, she taught me how to use new machines I’d never touched, and showed me some exercise modifications I’d never tried before. And she made me feel like I deserved to take up just as much space as everyone else: Watching her move around the gym with confidence and comfort empowered me to do the same.

I spent more quality time with someone I love

Between our work schedules and social lives, my sister and I don’t always get to catch up beyond, “Did you feed the dog?” and, “Is the dishwasher clean or dirty?”

These set-in-stone gym dates fostered more intentional time together than sitting on the couch scrolling through our respective TikToks at the end of the day. We laughed, vented, gossiped, and cut up like only sisters do. I’m lucky to call her one of my best friends, and our weekly workouts reminded me not to take that for granted.

Despite the month-long experiment technically being over, we’ve found that working out together at least once a week has become something of a habit—and one that we enjoy. Plus, I’m waiting for the day when I get to be the one belting “Get on Your Feet” outside her bedroom door.