By any reasonable measure, I shouldn’t be writing this. I shouldn’t be able to do much of anything. And yet, here I sit, thinking and typing. My typing is certainly no worse than it was five years ago. That was before my first running life abruptly ended.
Over the last month, I’ve had an opportunity to push against the limits of my compromised vertebral artery system. Vertebral arteries – “verts” – are the second major set of arteries that supply blood to the brain; the back of the brain to be precise. The verts account for about 20 percent of the total blood supply to the brain. When they are blocked, like mine were, the result is an ischemic stroke.
In 2017, I had a number of transient ischemic attacks, or TIAs, which are often called mini-strokes. The strokes were due to a blockage in my left vertebral artery. The result was a long stay in the Foothills stroke ward in Calgary.
I’ll repeat what I’ve said many times since then: the doctors that deal with stroke patients every day are heroes. I know this firsthand because the Foothills heroes stabilized me and saved my life.
The blockage in my left vertebral artery remains untreated. This is only possible because my body has made a rather ingenious adaptation to the blockage, by building secondary arterial connections to keep blood flowing to my brain. We were able to watch this in real time, on a video taken from an angiogram procedure. It makes for fascinating viewing.
As I pushed through a 16k run in the snow yesterday, or a 20k run in fine weather the Sunday before, I realized that I am a real-life experiment. While I am apparently able to cover these distances without too much trouble, it has not been a straight-line recovery. Just after my hospital stay, I had trouble walking around the block. Slowly but surely, I put my life back together. As you’ll gather from the title of this blog, I call it my second running life.
I barely managed a 500m walk/jog a month after my last TIA. A year later I finished a 5k race side-by-side with my wife. Last year we ran the First Half Half Marathon in Vancouver.
Now I’m at what I think is my upper limit. I can get through 20k, but not without discomfort. I know I’m at my threshold because my neck/shoulder are generally screaming for me to stop by the end.
Curiously, this is the same symptom I experienced before my strokes, when I was training at a much higher level. The pain was most severe during marathon buildups, and I’m certain that it was the first warning sign of the arterial problems I would have a few years later.
It occurred to me that I could perhaps use these pre- and post-stroke data points to estimate the change (if not the absolute amount) in blood flow to my brain. My assumption is that by comparing the usual measure of maximum oxygen uptake – the “VDOT” – I could arrive at an estimate of the amount of damage done to my vascular system by the strokes.
Before my hospitalization, I was training at a VDOT of between 50-52, based on my being able to run 1:25 to 1:30 for the half marathon. Last year, my wife and I completed a half marathon in 2:06, which suggests a VDOT of about 35. In both circumstances, I would consider myself to have been at my oxygen uptake limit.
Based on these empirical results, it would seem that I’ve experienced a reduction of between 30-35 percent in my ability to process oxygen in competitive running situations.
I’m not sure these estimates would have any value in a clinical setting, or whether it would be useful information in determining the next (if any) course of medical action. But it does make some sense, when you consider that I cannot come close to the kinds of performances I could manage five years ago. Even so, the fact that I can get through a strenuous run or race at all validates what I’ve come to see as the silver lining from this whole episode: I’ve been given a second chance, thanks to the remarkable machine that is my body. I know I mustn’t waste it.
My Second Running Life 