I normally push myself using the "Perceive Effort" principle. I know what my training pace is and where my race pace is but come race day you always go a little fast. The Ex2 5.5 mile trail run was my first race using the Sunnto t6c, Comfort Belt, and Foot POD. I knew going into the race my street pace is a high 6 minute per mile and for the trail I was looking for a mid 7 minute per mile. The last trail race 2 weeks earlier had my IT Band, in my right knee; all twisted up and reduced me to walk. Go into this trail race I want to start a little more conservative to determine how my IT Band was feeling and then pick up the pace.
Looking at my training log, for heart rate and EPOC ([Excess Post-exercise Oxygen Consumption)|http://www.suunto.com/suunto/Worlds/main/world_terminology.jsp?CONTENT<>cnt_id=10134198673963787&FOLDER<>folder_id=9852723697225037&bmUID=i2e6wJx] shows my heart rate slowly coming up for the first half and then a steady state at threshold, close to my max for the second. The EPOC is the amazing part for me as it matches exactly how I was feeling. I was putting it all out there the last mile and raced right to redline. When I came across the finish line, 6th in my age group, I had nothing left.