Oxygen Deprivation

A day like today calls for a long ride.  Warm air, low humidity, nothing on my schedule.  I’ve been building up to longer rides, but as I whined earlier in Wait. Weight? Don’t Tell Me!, it’s been a slow start to the season, and my shape is not what is usually is by the end of April.  I ended up doing 15 rides this month, though, so that’s a good foundation for the rest of the summer, except that I’ll be away from the bike for a while in May.

Anyhow, today I rode the 38.67 miles from here to Ashburn and back, via Hunter Station Road on the  way out.  The air was vibrant, bright, and warm, and moving somewhat swiftly in the range from NW to SW.  I promised my self I’d take it easy and ride at about 90% of my usual intensity to save energy, because today’s ride was a good 7 miles longer than any ride I’d done in 2010. (1)    But my vow was hard to keep.  I come up on a slow rider–or more irritating yet a fast rider who is freewheeling and rubbernecking instead of maintaining a steady pace–and when I pass that rider my instinct is to keep up the pace to assure they don’t pass me again.(2)   Not because I am racing, but because I like to pace myself at my own speed, and not be forced to ride at the pace of other people.

So by the time I got out to Ashburn I was feeling some fatigue, having battled a headwind/tailwind switcheroo all the way out.  More tail- than head-, but enough to keep me from settling into a rhythm.  Going home is more downhill, but was also relatively speaking more headwind.  I was averaging 15.7 mph when i turned around, and ended at 15.o.  (3)  So heading back I was “on a roll,” trying to keep my pace up, my cadence steady, and my effort even.  With the quartering headwind I experienced much of the time, though, I was drained.  By the time I got to the center of Vienna, Maple Ave., I had 2 miles to go.  I was too low on energy to really push it up the mile-long upgrade that extends halfway to our house from Vienna (the rest is downhill and level).  I was in oxygen deficit.

Oxygen deficit happens on a long ride when the body demands more energy than the lungs can provide by oxygenating the blood.  Without enough oxygen the muscles lose power, the brain responds more slowly and less acutely, thus handicapping the rider both in strength and decision-making.  One can, and I did, demand more of the body than it wants to give.  That puts it further into oxygen deficit, however, and one can’t sustain that very long.  (4)  So up the hill I went at respectable but not my best cadence and speed, down the other side, and home.  I had to force myself to look carefully both ways at the one remaining road crossing; oxygen deprivation short-circuits the brain’s usual cautionary role. (5)

When I got to the foot of Academy St. I did my usual “sprint” uphill past the house to the top of the street, followed by a U-turn and downhill glide into the driveway.  I pulled up, noticing that the garage door was open.  I removed the bike computer, went into the garage, hung up the bike, took off my helmet and gloves, got my sports drink to cool off with, and went inside.  Only then did I see out the front door that Jane and grand-daughter Emma were sitting on the front stoop.  I hadn’t seen them coming in!  That’s the tunnel vision, reduced visual and mental focus, of oxygen deprivation.  I was wholly concentrated on getting my body through the last several miles of the ride.  I was less than fully comprehending, less than fully rational.

Some other time we’ll talk about “pain,” which I deliberately put myself into today.  I finished at 4:00.  It’s 10:30 and I still feel pretty “knackered,” as the British say.  But oxygen deprivation in and of itself is worth being aware of.  You’re never much aware of it while you’re in it, though.  No perspective.

___________________________________________________

(1)  That in itself is evidence that I’ve not gotten into my usual shape.

(2)  Today it was a young and athletic couple.  He had a Scott; I didn’t catch her bike.  But they couldn’t quite accelerate past me smoothly at the same time.  She’d forge ahead, then he’d try but couldn’t quite get past.  She’d slow down to help him catch up; I’d go past her; he’d pass me; she couldn’t get by, etc.  Finally they cut the crap and took off, but it was ludicrous, bordering on harassment.  At on point, shortly before they blasted by, he said “you can just pass us if you want.”  What was that all about?

(3)  The ride to Ashburn is completely on the Trail except for the short loop of a couple of mile that takes me up Hunter Station Road, and then around through the eastern reaches of Reston and back onto the W&OD Trail at Sunset Valley Road.  Fundamentally the Trail goes uphill from Vienna to Reston, level out to western Herndon, and then down and up to Ashburn.  An old railroad line, it keeps to a 3% or less grade except for a couple of points where over- and underpasses have been added.  But it gains probably 300 or 400 feet from Vienna to Ashburn, so it’s more downhill on the way home.  When the wind is from the S to SW, though, it is a quartering headwind on the way back because the trail runs roughly SE into Vienna.

(4)  I confess bad planning too.  Leaving om my ride at 1:00 pm, I’d eaten only a small bowl of cereal and some milk this day, and had a mug and a half of coffee.  Caffeine can only take you so far when power is an issue.  I forgot to take along an energy bar as I had planned.

(5)  This condition is not the same as a “bonk,” in which all the available short-term energy in the body has been used.  That’s far worse and more painful.

©Arnold J. Bradford, 2010.

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