Some of the hottest new exercise trends are actually just updates on yesterday's classics. See how new classes compare to old-school favorites.
Then: Boot Camp
What they have in common: Both utilize military drills like push-ups and jumping jacks.
Why new is better: "CrossFit is more intense," says Carol Espel, senior director of group fitness and Pilates for Equinox.
What they have in common: They're both dance-based, low-impact aerobic classes.
Why new is better: "Zumba moves faster, so you get even more cardio conditioning," Espel notes.
Then: Lotte Berk
Now: Physique 57, Barre3, Figure 4
What they have in common: Exercise moves are done on a ballet barre.
Why new is better: According to Espel, "Classes use light weights and body-weight moves like push-ups and planks to tone."
Then: Body conditioning
Now: Metabolic training
What they have in common: Both use weights to improve strength and endurance.
Why new is better: "Metabolic training is faster and more athletic," Espel says.