Subject: Asphalt (road) vs Concrete (sidewalk)Concrete has been proven (thanks google search ) to be very hard on your knees and ankles. It has the benefits of the fact that it's generally safer, better lighting and no cars.
Asphalt has less damage on your knees and ankles and has more give because it's softer. However, you are on the roads and cars can come close at times.
Which do you run on, or would you prefer to run on? |