Not arguing, just repeating what the Cardiologist said. Biking is definitely easier on me, for sure. Depends on how far and how much, like anything else. I typically ride about 10-15 miles, but that is over a very hilly trail with a lot of ups and downs, so I get a pretty good burn. What I want to do is ride this trail they have near Ogden that runs along the Weber River, and goes all the way from South Ogden to the mouth of Ogden canyon, about 20 miles. Some of the up grades are killer. Not ready for that right now.