Yesterday was a speed work day. I headed over to the CDM track to put in some 400 meter intervals. The planned workout was 2 mile warm up, 7 400 yard intervals with 400 yard rest, 1 mile warm down for a total of 6.5 miles. Set a pace at 11:00 (allows for rest during the intervals) and around and around I went! Ended up the run with an overall 10:15 pace.
The purpose of these interval workouts is to increase VO2Max - our body's ability to absorb oxygen. An effective VO2Max workout should be run at 90% to 95% MHR for somewhere between 2 and 6 minutes. Obviously, 400 meter/yard intervals won't get me to 95% MHR for two minutes per interval. I looked at my data this morning and can see that even though the amount of time at VO2Max is in the 1 to 1 nd a half minute per interval range, I did spend a total of 10 minutes at VO2Max!
One thing for sure - I'm happy that today is recovery pace!