I have been flirting with injury (I believe) as a result of running in Central Park. I have a slight strain in my upper left leg and some minor soreness in my left arch. So I think I need to stick to the more forgiving and even surfaces offered by the track and treadmill. I have been going to the track and running a kind of fartlek based on effort and set intervals. A typical workout (that I did Saturday) is 24 x 90 seconds with a 30 second walk recovery. The total workout time was 48 minutes. The 90 second intervals are based on a perceived effort with maximum effort being maximum AEROBIC pace. I try to work up to my maximum aerobic pace after the first 10-15 minutes and maintain that effort for the remainder of the workout.

Sunday I did 30 x 30 seconds hill running with 30 second rest on the treadmill working up to 6:00 pace at a 4 degree incline.