Fitness trainer Paul Christopher shares some fitness slogans and goes into what they mean. For instance, “at the edge of uncomfortable, greatness happens” and “the only thing that easy and results share are two letters.” To create change when you’re working out, failure and fatigue are a necessity. In order to create change, you must reach a workout intensity that will instill that change. A scientific principle called Wolff’s Law states that the bones in your body will adapt to the load placed upon it. If your cardio is intense enough, your heart and lungs functioning improves. If you put enough weight on a barbell, you’ll get stronger. To improve flexibility, strength and cardio, the intensity of your workout is the key.