Interval training

Every now and then, something in life acts as a harsh reminder that "I am getting old".  Interval training served as this cruel reminder yesterday.  I ventured to a local high school to use their track for some 800 meter repeats.  I strapped on my Polar heart rate monitor (used to gauge workout intensity...as if my breathing rate was not good enough) and began my first 2 laps.  Pleased with my 3:25 time frame, but being realistic, I set my goal to do the remaining 3 x 800 meters in under 4 minutes each.  My rest intervals were spent jogging until my heart rate lowered between 120-130 bpm.  Although labor intensive, I am happy to report that I reached my goal.  The thought that I knew I would be blogging about this training session provided good motivation to "leg out" the last 200 meters of the final 800.  Fairly spent, I started thinking about the mile repeats that I want to work up to in training for the half marathon that I plan on doing in October.  To recap:
1.  4 x 800 meter repeats
2.  Rest intervals (jogging until HR= 120-130 bpm)
3.  Total mileage= 3.25 miles