Toe Running
Another topic I will mention is that of form, specifically toe running. Throughout high school and my first two years of college, I was the world's worst heel striker. No kidding. Teammates commented on the fact that I would heel strike even on pretty steep uphills! I was unable to run on my toes for more than 50-100m at a time.
For those of you unfamiliar with the pros and cons of toe running, let me explain very briefly. By landing on the ball of your foot (toe running) and springing into the next stride (much like a diving board), the turnover time is significantly reduced versus heel striking -- landing on the heel, rolling to the midfoot, then pushing off the toes. There is much debate regarding the efficiency and proneness to injury of these respective techniques along with landing fairly flat footed, so I will avoid that topic. There is no question, however, that toe running is by far the fastest method.
Now back to my story. My first year at Oregon State, I decided I really needed to learn to run on my toes if I wanted to get faster in the 800m. Early in the track season, I spent a week running at least a mile continuous on my toes EVERY day. Remember now, before that I could hardly handle 50m! Obviously the pace had to be kept slow at first. I spent the next week being afraid of stairs, my calves hurt so bad. After the initial week I did not force the issue, toe running only on intervals. Around mid-season I ran the 800m and lowered my PR from 2:18.0 to 2:11.2, not too shabby for a mere style change. Also, after that first week of toe running, it became completely natural to run on my toes for the entire 800m, and throughout most intervals of 400m or less. I wish I had known about this sooner.
Metabolism
Here is another advantage of high intensity speed work -- the effect it has on your metabolism. A common misconception is that long, slow runs will burn more calories than will short, fast runs. The reasoning is that although calories are burned at a slower rate, the longer duration will tip the scales. However, this ignores several important factors. The first is quite obvious; higher intensity means more calorie consumption per minute or hour or whatever. You could also argue that the time saved by the shorter, faster workout leaves more time in the day where you will still be burning calories if nothing else than by breathing.
But the most important reason why high intensity workouts are superior is this: Research has shown that the metabolism can remain at its highest level for up to 17 hours following high intensity exercise! Who's hungry? What would a running site be without a somewhat out of context quote from Once a Runner, "If the furnace is hot enough, anything will burn."
