CrossFit Train sits in a no-frills warehouse space near Highlands, and the 4.9 rating with 150 reviews tells you the coaching is the real draw. This isn't a big-box gym where you wander around confused. Classes are small, coaches actually watch your form, and the community shows up for each other on the whiteboard and off it. You'll find a mix of longtime Denver CrossFitters and people who swore they'd never try it, all sweating through the same brutal 12-minute AMRAP. It's intense but never intimidating. Expect barbells, gymnastics rings, and a lot of encouragement between sets. Good for anyone who wants to get strong, make friends who'll notice if you skip a week, and leave every session a little wrecked in the best way.