Even if kickboxing or step aerobics aren't your ideal fitness experience, working out in a group can buoy your spirits and help motivate you to push yourself. That being said, occasionally there's a sub standing in for your favorite teacher and you just can't hack it. Or you try a new class, realize you're in over your head, and fear injury if you finish. I have quietly moved to the back of a workout studio and slipped out the door to finish a workout on a treadmill when a class just wasn't moving enough for me. What about you?