Check out the transcript of a message board discussion with Weather Expert, Ingrid Amberger. Dr. Jeffrey Masters, Director of Meteorology for the Weather Underground Web site, answered student weather and winter storm questions in the winter of 2001. Dr. Masters received his B.S. and M.S. degrees in Meteorology from the University of Michigan.
It is easier on the joints than running. It is non-impact and therefore safer and easier on the joints. Biking is an exercise that you can do even at an older age. It is a great aerobic exercise for losing weight and increasing cardio endurance.
Walking is a weight-bearing exercise; biking is not. This means that when biking, the bicycle is the machine moving and doing some of the work for you. When you walk, your body is the only thing working.