We’re in the third decade of the 21st century, if you’re currently in your 40s, 50s, 60s, or beyond, then you’ve been a part of the modern fitness industry. To those of you who have been exercising most of your adult lives, congratulations: You are in the first generation of active adults who have had access to gyms and exercise throughout their life span.    The original intent of exercise was to sculpt attractive bodies of lean, well-defined muscle. Now, scientists have had the opportunity to study how exercise affects the aging process. What we are learning is that exercise, especially high-intensity exercise, just may be the key to aging awesomely.    Today’s guest, Pete McCall, is author of Ageless Intensity: High intensity workouts to slow the aging process. The book includes four aspects of fitness that will help turn back the clock. As Pete highlights in his book, focusing on exercise  intensity may be the key to reducing the biological effects of time.    I’m excited about this conversation with Pete, because he always provides straight-forward, science-backed information. But more importantly, he gives you useful tricks and tools to control aging and keep you feeling young.