7 Rookie Workout Mistakes to Avoid

Kickboxing

Rookie mistake: Trying for a TKO

What the pros know: It's easy to get caught up in the excitement of a fast-paced class and start jabbing and hooking like crazy. But punching too hard without a solid target can lead to injury. "Boxing technique is not about power alone. It's about form, style, balance, speed and control as well. You'll develop power as you progress and work the heavy bags and targets," says Marcus DeValentino, a cardio kickboxing instructor in Aiea, Hawaii. To keep your muscles loose and nip the "death-grip clenched fist" in the bud, try DeValentino's tip: Concentrate on keeping your pinky finger relaxed when you punch, and let your shoulders bounce while you move.