9 Ways to Tell If You’re Exercising Enough

What it means: You might be working with improper form. "Bad posture, not lifting your knees or keeping your body in one position throughout can have a negative impact on your results," says Minardi.

How to adjust: Throughout class, remind yourself: Form is what counts, not your ego. "It's not how fast you move but how your body moves while you're doing it," says Minardi.