|Even a runner's body produces energy in this way.|
Since my High School I have been a fan of ceteris paribus – "given all other factors unchanged". Today I came to feel again that sometimes it does not hold, and the results do not approximate the expectation.
I went for a good run on Tuesday night. I did not expect the weather to be so windy and cold, so I had to put on a hoodie (I never do). It was in the evening; I was a bit tired: hardly ideal conditions. After a few kilometres on the city pavements, I hit the runners'/cyclists' lane and could accelerate. The whole run felt very good, I covered 13 km at 4:41 min/km. The last 10 km were at 4:41. Here are the data:
I knew it was a useful workout. So over the week I thought about replicating the intensity. This morning I got a chance to run, so I put on my running shoes and set off. I intended to hold back for the first two kilometres, then accelerate to 4:30/km, and fade out to 5:00/km at the end, all in 11 km. The conditions seemed perfect: I was fresh (morning), had better shoes on (I did run in fivefingers the other day), and did not need a hoodie! Yet it did not work out as planned:
|km n.||avg. pace|
What happened? Based on my feeling during the run I suspect the two important factors (the ceteris paribus not met) working against me were energy and tiredness. I avoided running hungry on Tuesday by eating two snacks (horalky) about half an hour before the run. This morning I had a banana (and not much last night). Perhaps unsurprisingly, I felt like unable to keep with 4:30 at kilometre 4, and 5, and all but abandoned the ambition of 6 or 7-km span at 4:30. It felt a bit like in some marathons: you will to go on or accelerate, but the return is modest. Cardio feels ok, but the legs do not respond well. Empirically, this would suggest that two (early) horalky are better fare than a banana. More importantly, a half-empty stomach is not good enough.
The other factor is tiredness. Had I felt soreness in my muscles, I would not have been so adventurous. Still, I must have forgotten Pfitzinger's rule of thumb for tempo runs or long runs: keep 4 days between them (P. Pfitzinger: Advanced Marathoning). I did not. I'll learn.
Perhaps I will be able to get close to 7-10k at 4:30 soon. Obviously, I need some time off first.