Intervals at the track.

Today after work I headed out to the track at Muhlenberg College and did intervals. I ran one lap at 85 strides per minute then walked one lap. I did this for about a half hour. I bought a Seiko metronome from the Internet for $20.00. It is easy to set up and loud enough for me to hear while running. I read in Chi Running that you should try and run at 90 strides per minute which is tough for me to do so I am going to try to work up to that by doing intervals once a week.