I am trying to get into a routine of running every other day and circuit training every other day. On my run days, I am doing about 6 miles  - 4 miles hard with a warm up and warm down. My best time to date for the 4 miles is 28:40 (7:10 pace). My heart rate went over 160bpm during that run. I find that my heart rate goes up much easier when I have a day of rest. My circuit training consists of stride jumps, alternating with push-ups, pull-ups, curl-ups, and dips. I take very short rest between exercises so my heart rate stays over 120bpm during the workout.