To get the most out of your workouts (cardio and strength) you need to be out of your comfort zone. I like interval training because it allows you to work out effiiently and effectively more than your more traditional steady state cardio workouts. A typical cardio interval workout begins with a short warm up, a moderate/hard interval and a recovery segment, you just repeat the process until you have reached 20 – 30 minutes. You will notice that you get more done in 20 – 30 minutes of cardio then you did with 45 – 60 minutes of steady state training. There is an added benefit – the workouts are shorter, more effective and far more fun! You must – however, be out of your comfort zone during the harder/intense segment. A way to gauge this is by asking yourself the following: On a scale from 1 – 10 with 10 being the hardest, how hard are you working? Are you out of breath? Are you sweating? Are you grunting and reaching your limits? A Rule of thumb is that you want to be safe, to have fun, all while you are out of your comfort zone!