I went to the track yesterday. School starts in a few weeks and the tracks then become difficult to use, but I needed to get in one workout on the track. I've got a 3 mile course marked out in quarter miles that I can back up with GPS, but 100 meters is tricky. I needed to get a feel for how many strides that is, so I could create my own 100m course for when the tracks are all busy.
The plan was to run 16x100-100 [for the uninitiated: 100 meters fast, 100 slower, repeated 16 times]. Running hard for any length of time on the sharp turns of a track chew up my left heel; the past two years, when I've started running on a track, I've pulled up injured after a couple of weeks. I had to keep this in mind.
Now for the post-graduate level explanation of the workout. The first few seconds of a sprint are dependent upon creatine phosphate, which is quickly consumed and regenerated. If one repeatedly does short, fast bursts, one can build up the amount of creatine in muscles, so one can run at top speed for up to 10-15 seconds without dipping into the glycogen-dependent anaerobic system. These few seconds can be important for a final sprint. Early in training, this workout drains the creatine pool and causes one to use muscle glycogen; one knows one has developed the creatine pool sufficiently when the workout can be done without struggling.
I tend to "start hot," going out as fast as possible, but this is an extensive interval session, where it is the cumulative effect of many repetitions that one wants, so I had to consciously keep myself in check. Because each fast section has a flying start, rather than a standing one, the stress on my heels should be lessened.
I haven't run fast in a long time. I know I've developed a lot of bad habits in form over the past few years and I can only concentrate on one at a time, so this time out I was thinking about getting my arm swing right, thumbs grazing the hips and coming up to eye level; knee lift, ankle push-off and especially back kick will have to come later.
I thought I was hitting 16-17 seconds for the fast 100's, but it was only 20 - how did I get so old and slow?! [and, yes, 5:20 mile pace is slow for this workout] Fortunately, I kept steady, rather than continuously slowing. My heart rate, however, skyrocketed, hitting 179 (max=184, or maybe less now) and only dropping to 173 in the 35-37 second recoveries.
I had to bail after doing 12. I'm just not used to doing this and I didn't want to kill myself. I decided to just fill out the hour with a recovery jog. And I couldn't do that, either! I trudged the next quarter mile to make it an even 3 miles for the day and quit. My left heel was just a very bit tender (the next morning it was stiff).
How's that for analysis of 4 minutes of running hard?
It was good to be back. Good not to be wheezing. Good not to be limping. Good to have a goal again. Good to have a real workout, rather than just playing around.
(and walking slowly in recovery, 100 meters is 63 1/2 strides. 47 when running)
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