The Powers and Pitfalls of Group Fitness: Why More Doesn't Equal More

Years ago, when I was pushing forty, I was a group fitness addict. Body Pump, Body Combat, Body Attack, CXWorx, RPM — if it was a Les Mills class, I was there. Sometimes twice a day. Sometimes 10-12 classes a week.

I thought more was better. I thought if I just kept showing up, kept sweating, kept pushing, I'd eventually get the results I wanted.

I was wrong.

Now, I still do group fitness, CrossFit, to be specific. And yes, CrossFit is technically group exercise, just a more hardcore version. But my approach has completely transformed. I've traded high-volume cardio classes for strength-focused training. I've learned that strategic beats relentless. And looking back, I can see both the value and the limitations of my group fitness obsession.

This isn't a takedown of group classes — they served me well for years, and I'm still in the group fitness world. But it is a cautionary tale about confusing volume with progress, and cardio with strength.

The Power of Group Fitness

Let me be clear: I'm a believer in group fitness in any guise or form, especially for beginners. Group classes offer variety, structure, and community. They're a gateway into gym life, introducing fitness novices to movement patterns, exercise terminology, and the rhythm of regular training. I made some of my longest-lasting friendships in group fitness classes.

For women in particular, group classes can be an accessible introduction to resistance training. Many classes incorporate compound and isolation exercises that build foundational strength. And that's vital, especially as we age and face natural muscle loss.

Group fitness also offers something deeply human: shared suffering. There's a unique motivation that comes from working out alongside others, from feeding off collective energy, from knowing you're not alone in the struggle. It's why CrossFit works for me now: the community, the camaraderie, the accountability.

Where I Went Wrong: The Overtraining Trap

So, with all these positives, where's the problem? The problem is over-reliance. The problem is thinking more equals better. The problem is mistaking volume for progress.

My group fitness journey began in my twenties. I started with a few classes a week: Body Pump, spinning, aerobics. I fell in love with them. And then I fell too far. Within months, I was doing 2-3 classes per day. During periods of life transition and upheaval, I leaned even harder into group fitness. It was the one constant I could control. Les Mills, my program of choice at the time, was offered globally, so I could walk into any studio and know exactly what to expect. In a life full of flux, that predictability was comforting. But comfort isn't always growth.

I started scouting classes everywhere, clocking up 10-12 per week while holding down a full-time job. I began experimenting with other formats while maintaining my Les Mills addiction. And here's the thing: I plateaued. Hard.

Despite all that effort, all those hours, all that sweat, my body stopped changing. I was lean, sure, but I didn't have the definition I wanted. I couldn't understand why I wasn't seeing results. The answer, it turns out, was simple: I was overtraining, under-recovering, and prioritizing the wrong stimulus.

Why More Doesn't Equal More: The Science of Overtraining

Here's what I've learned about the inverse relationship between volume and results when it comes to group fitness:

1. Most classes are cardio-dominant

Yes, cardio helps shed fat. But when over-exploited, it also eats away at muscle. The body clings to fat and cannibalizes muscle when you overdo cardio. To build and maintain muscle, especially as women over 30 lose approximately 1lb of muscle mass per year, you need to prioritize resistance training and moderate your cardio output.

2. Excessive cardio undermines strength gains

If you're lifting weights but doing disproportionately more cardio-based classes, your net gains will be reduced. Cardio becomes counterproductive to your strength efforts. Cardio has a place in a balanced fitness regimen, but when you're doing 10+ classes a week, you're overtraining and gleaning little to no results.

3. You won't get the aesthetic results you want

I slogged it out with classes for years. Initially, I saw results. Then I plateaued. If you want to be cut and defined, you need progressive resistance training. There is no substitute.

4. Lack of recovery sabotages muscle growth

Muscle builds during recovery, not during the workout itself. When you're doing cardio-based classes day in and day out, you're not giving your body the chance to recover and adapt. Rest isn't laziness. It's strategy.

5. Overtraining spikes cortisol

Overtraining leads to chronically elevated cortisol (the stress hormone), which for most women manifests as fat gain around the waist. You might be doing 10 classes a week and wondering why your abs aren't flat, why you look continually bloated. The answer is stress—physical stress your body can't recover from.

What Changed for Me: From Cardio Addiction to Strength Training

A coach eventually helped me see what I couldn't see myself: I needed to wean off excessive cardio-based classes and embrace strength training. That shift changed everything. My body composition improved. My strength skyrocketed. My energy stabilized. I stopped chasing volume and started chasing progress.

Now, I do CrossFit which is still group fitness, just a very different flavour. CrossFit allows me to prioritize resistance and strength training in a way those cardio-heavy classes never did. I'm lifting heavy, building muscle, and focusing on progressive overload. The HIIT and cardio elements are still there but are interspersed throughout the week as part of my WOD and conditioning workouts. They're balanced with proper strength work and skill development. And crucially, the programming demands recovery.

I'm still showing up to group classes. I'm still feeding off that collective energy and community. But now the focus is strength-first, not cardio-dominant. Now I'm training strategically, not just relentlessly.

I haven't abandoned group fitness. I've just found a smarter way to do it—one that prioritizes what my body actually needs: resistance training, progressive overload, and adequate recovery.

The Takeaway: Strategic Training Over Volume 

I'm still an advocate for group fitness, especially as an entry point into the fitness world. But if week after week, all you do is cardio-heavy group classes, you won't achieve the results you're after.

Less can be more. Quality trumps quantity. And your body doesn't reward you for showing up exhausted; it rewards you for showing up strategic.

If you're stuck in the cycle I was in, doing class after class, wondering why your body isn't changing—consider this your permission to do less. Prioritize strength. Embrace recovery. And remember: fitness isn't about how much you can endure. It's about how well you can adapt. Your body deserves better than burnout disguised as dedication.

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*This post originally appeared on Pushingforty.co.uk in 2017 and has been updated with new insights for 2026.