Forget 12-3-30—This Treadmill Workout From A Victoria's Secret Angel Trainer Gives The Best Fat-Burning Results

Whether you want to lose excess body fat or just feel your very best, exercising regularly is a non-negotiable part of your health routine. Lifting weights and doing resistance training is crucial for building lean muscle, which helps boost your metabolism, improve your immune system, and prevent injury; but don't forget about the heart-healthy benefits of cardio, which can also help speed up the weight-loss process. There are many different forms of cardio, but they can all usually be thrown into one of two categories: HIIT (high-intensity interval training) and LISS (low-intensity steady state).