Bike Forums - View Single Post - Bonked Hard Yesterday
View Single Post
Old 11-05-17, 09:42 PM
  #10  
SethAZ 
Senior Member
 
SethAZ's Avatar
 
Join Date: Oct 2013
Posts: 1,394

Bikes: 2018 Lynskey R260, 2005 Diamondback 29er, 2003 Trek 2300

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 562 Post(s)
Liked 324 Times in 179 Posts
I don't want to sound like a doubter, so please don't misinterpret me. I've ridden tons of miles since around 2009 while also on a very restricted diet, and I've also bonked several times, so believe me when I say I know it's possible, and what it feels like. That being said, the shortest distance I ever bonked on was 23 miles into a 25 mile ride. I was eating very little, riding way too much (it was during one of Strava's distance challenges, if I recall the Festive 500 one of the years I did that). That ride was my second ride of the day (one in the morning, this one was in the afternoon) and with insufficient calorie intake in between I was in a very low energy state.

Still, 9 miles in implies either that you would have had to have been in a nearly fully depleted glycogen state at the start of the ride, with very low blood sugar, and simply unable to metabolize enough fat to keep up with the energy requirements. That typically would imply a very high level of effort.

If you don't mind me asking, do you wear a heart rate strap during a ride? If so, what heart rate zone were you in during this ride? I ask because most folks should be able to plow on on bodyfat alone in zone 2, and really only get themselves in trouble in sort of mid zone 3 or higher levels of effort.

I'm wondering if what you experienced was really a bonk, or something else. What cadence do you typically ride at? I ask because if you're typically in like the 60s or 70s it's possible that you simply mashed too hard into that wind and, to use the popular metaphor, burned all the matches in your book, and had wasted muscles. Blowing your muscles up like this can feel pretty devastating, which someone who hasn't really bonked before might think was a true bonk.

Btw, when I bonked at mile 23 in that one ride it was mile 23 of a 25 mile ride, and I went from like 18 mph speed one mile to like 10 mph or less a mile or so later, with a very real dread that I literally could not make it the last two miles home. It was devastating, and when runners call it "hitting the wall" they aren't kidding. In a true bonk your brain is literally shutting down your body's muscles in order to prevent the brain from being so starved of necessary calories that dain bramage could result, or worse. This is a very different thing from simply burning all your matches and being so wiped out muscle-wise that you don't think you can go on.

If, in fact, it was a case of simply burning out your muscles by mashing at too low of a cadence into that strong wind, have you tried pushing your cadence higher? When I first started riding I thought that the 60-70 rpm I was doing was perfectly normal. After reading about higher cadence I starting pushing my cadence up and got used to it, and now on good training rides I try to keep my cadence at a minimum at like 85 rpm, and typically between 90 and 100 rpm. If I wait to shift to a harder gear till I'm in at least the upper 90s or even low 100s then my cadence won't fall below 90s after the shift. Another reason why a compact chain set and a wide range of 1-tooth difference cogs in the rear is a blessed thing.

Anyhow, please forgive me if you really did bonk as in get to a point of such low blood energy level that your brain actually shut down the rest of your body. I don't mean to be a doubter, but I do think it's entirely possible that something else that felt really bad was going on, but not technically a real bonk.

Btw, the other bonks or impending bonks I've experienced were all in the 45 to 55 mile range during moderately high intensity rides with insufficient energy. A 9 mile bonk would be quite an aberration, and if you really did bonk at 9 miles, regardless of the nasty wind, then you definitely need to do some rejiggering of your nutrional/exercise balance.
SethAZ is offline