If you're ready to take your fitness to the next level in 2012, fitness expert, celebrity trainer, and star of Personal Training with Jackie: 30 Day Fast StartJackie Warner recommends trying "cardio acceleration."
Cardio acceleration basically means that you add one to two minutes of high-intensity cardio between your sets of resistance training. At home, you can do this by doing 100 rotations with a jump rope when doing any weight lifting or by adding squat jumps after you do a set of squats at the gym.
"It's brutal, but I guarantee you will feel sore," Warner says. "And you want that soreness so that your body changes."