Group fitness classes are super popular lately. The boom really started when people realized how enjoyable and motivating the group atmosphere of CrossFit was.

Now gyms everywhere are following suit. Your local YMCA has dozens of moms sweating their buns off early every morning. OrangeTheory’s popping up everywhere.

Meanwhile, fitness guru rail against this type of training on social media.

Why the hate? Are these classes just a trend, or can they be effective?

One of the biggest issues with group fitness classes: they’re very hard to individualize. Dozen of people being trained by a single person means very little one-on-one attention.

Everyone has different needs. The ideal training program for you would look much different than the ideal program for your neighbor. Group fitness classes have dozens of people following the exact same routine. This will keep you from making as much progress as you could with a plan designed specifically for you.

The biggest key to make progress towards building muscle and losing body fat? Progressive overload. Basically, doing more work in the gym over time via more weight, more reps, less rest, etc.

Problem with group fitness classes is, they’re often based on strictly band, bodyweight, and light dumbbell exercises.

Why is this a problem? Effective reps.

The concept of effective reps is basically: Only the last few reps of a set are causing your muscles to work hard enough to cause growth.

Achieving effective reps is easier with heavier barbells and dumbbells. But light, high-rep sets have to be taken close to the point of failure to achieve “effective reps”.

Plus, it would be dangerous for dozens of people to be doing challenging barbell movements with heavy loads, without one-on-one supervision.

To avoid injuring dozens of people at once, group classes push the biggest aspect of making progress in the gym (progressive overload) to the back burner.

I like to prescribe the following guideline to progressive overload: If you can easily perform (at the most) 15 reps, add weight. If you can hit the prescribed rep range for multiple sets with less than 60 seconds rest between, add weight.

All that being said, there are positives to group fitness classes.

The community aspect is awesome. There’s a reason group classes are taking off. They’re fun! They make you feel like part of a community, all striving towards the goal of being healthier.

A program designed specifically for you is the best way to do things. But if you can’t afford it, or can’t motivate yourself to workout, group classes are much more effective than doing nothing.

If you just enjoy the group atmosphere more than going at it on your own, more power to you. The best program is one that you enjoy and will do consistently.