I see this everyday as a Chen-style tai chi teacher. Boomers decide to get into shape, to discover that it will kill them! I give the same great workout, but at a slow pace with slow movements that build strength in the legs & engage the muscles throughout the body. When folk discover that it is also a deadly martial art, they realize the movements are more than just health & wellness, & it adds a unique perspective to their workouts. My people are amazed that something so graceful & slow makes them sweat so much! Harvard Medical school & the Arthritis Foundation highly recommend tai chi for exercise! Maybe he needs to find a tai chi class!