another tempo run

I was dreading the last tough workout: 3X 2miles tempo, then 9-10 miles easy. I even postponed it a day because I was tired. The peak of training made its presence known this past week. Basically, my legs are almost always tired, I sleep more, and like the dead. Yet the tiredness seems to melt away quickly once I've warmed up and it has become easier to run too fast.

This was what I was hoping for. This hasn't been the most regular marathon training cycle (two trips, two bouts of gut illness (mild, fortunately!); I wasn't sure if I'd feel the usual fatigue, the usual sharpening, particularly since I didn't boost mileage like before. I don't feel quite sharp now but I hope to soon, now that the tapering has started.

My tempo workout on Wednesday was more tiring than expected, and so I pushed the last tough workout from Saturday to Sunday. Saturday was hot and humid; it would have been better for acclimatization, but I've had plenty of that already this summer, and excuses were even more plentiful.

The weather on Sunday was anything but punishing. 18C, drizzling, it was amazing. My tempo pace was about 10-15 seconds/mile faster, and the run afterward was easy until the last mile or so. It felt a lot better than last time when it was hotter and I'd cut the workout short.

A curious thing happened, though, shortly after I'd stopped to walk after the last tempo segment. I know I shouldn't stop suddenly, but I wanted to put my shirt back on and get a drink of water, and warm weather actually gives me a bit of leeway by keeping my heart rate elevated. Otherwise, it drops suddenly and could trigger SVT, particularly if I bend down or turn my head while inhaling.

That is what happened. I didn't get to the water fountain; I put on my shirt, walked toward the fountain and, boom! I pressed my neck (as taught) and it went away quickly. Still, it compounded my fatigue and when I got home shortly after, I thought about dropping the rest of the workout. I drank a protein shake, reconsidered, and went out with the dog. The 9ish mile run was great, easy, relaxing. There was a moment where it was incredibly peaceful, perhaps the most tranquil moment I've had in a while. We were running by a willow tree without anyone else around, there was a mist of rain, and the path seemed almost frictionless.

During the rest of the run, I stopped a few times for water, no problem, but when I stopped at the end, I could feel the pressure of the trigger again. It felt urgent to breathe faster than required; it was uncomfortable to hyperventilate slightly but I did that for a minute or two and the feeling went away and everything settled back to normal and there was no SVT.

My interpretation: I've gotten used to 30ishC humidex. Heart rate was raised, but a greater percentage of blood went to surface capillaries and perhaps did not get as deoxygenated (I'm not entirely familiar with this aspect of physiology, but I'm assuming that muscles have greater oxygen demands than skin). When I stopped, my heart rate stayed elevated and oxygen levels rose gradually to normal. Yesterday was considerably colder. More of my blood circulated in my muscles and got deoxygenated further. When I stopped but was anticipating continuing the run, things stayed revved, but when I stopped finally, things dropped suddenly, but there was all this CO2, something has to be done, synapses fire, adrenaline and countless other biochemicals release and, voila! whoops! the 2nd time, the low oxygen levels made me breathe more quickly instead. I might ask my cardiologist about it. It's been ages since I've felt SVT--more than a year, I think--and it seems so bizarre that it should happen on the coldest run in a while, unless the coldness is the cause.

So I guess I will regain some speed as the temps cool; I'd thought that I'd acclimatized well but hadn't realized how underserved my muscles really have been, and that I really should be going faster. Meanwhile, I just have to be careful and coast to a stop gradually, like I had been doing before it got hot.

I jogged six miles this morning. It was hotter and I wore a long-sleeved shirt. No problems, not even a hint.

Reassured, I finally signed up for the marathon.