Cardio is important for strengthening your heart, lungs, and muscles, but you don't need to go full force every time you work out. Whether you enjoy running, biking, swimming, dancing, or some other type of cardio, dedicate one day a week to an easy day. I don't mean rest completely and do nothing physical, just do a lighter version of your regular cardio workout. Doing only tempo runs or sprint intervals can be really hard on your joints. Slowing down allows your body time to adapt to the demands you place on it with your tougher workouts. I find Mondays a perfect day to put this idea into practice, how about you?