As a former high school four hundred meter runner, track and field is my favorite sport.  Because of this, I try to run about fifteen miles a week.  About a year ago I was running in Prospect Park and my knees buckled.  My doctor advised me to use a knee brace and start biking instead.  A few days later, I went to the bike shop and purchased a bike.  Soon after, I was biking to work; from Bedstuy to midtown Manhattan.  At first, it was very scary riding in traffic.  However I was amazed to see how many people rode to work.   My first trip over the Williamsburg Bridge was murder on my legs, but I did not quit.  Today I ride almost every day.  I also recruited a few friends to join me.  We ride every weekend from Bedstuy to various parts of the city.