Finally joined the bonking club
lettingthedaysgoby
Posts: 1,489
Urgh. Just got back from the single most unpleasant time I’ve ever had on a bike 
Have always heard the tales of bonking, but until now had that “just how bad could it really be” feeling about it.
Turns out, it can be very very bad. Just 30 miles into a 50 mile ride and my world seemed to fall apart :shock:
God knows why, I’d had my usual breakfast and coffee. Just one of those things I guess. I’ll blame the heat
Have always heard the tales of bonking, but until now had that “just how bad could it really be” feeling about it.
Turns out, it can be very very bad. Just 30 miles into a 50 mile ride and my world seemed to fall apart :shock:
God knows why, I’d had my usual breakfast and coffee. Just one of those things I guess. I’ll blame the heat
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First time I suffered I was 16 and went on a hard training ride with a club in North London. I was so tired one of the guys ended up pushing me along the A10 to get me home !!!!!
https://en.m.wikipedia.org/wiki/Reflex_syncope
That’s as bad as I’ve ever experienced.
Ah well, made it to the cafe and ate ALL THE FOOD which seemed to cure things.
Did you get off your bike and lay down on a grassy verge somewhere?
Did all those 500W+ sprints from earlier in the ride catch up with you?
I had a ~40 mile crawl on Tuesday, could tell within minutes of setting off my legs imply had no intention of working, but it had to be done to get my first Strava Distance Challenge completed. There might not have been very many hard power training sessions in July, but the extra ~33% of mileage compared to a normal month caught up with me and wanted payback.
2020 Voodoo Marasa
2017 Cube Attain GTC Pro Disc 2016
2016 Voodoo Wazoo
Is this the correct diagnosis? Running out of sugar is not mentioned anywhere in the link. Unless, being out of energy, blood pressure is not sufficient to reach the brain and it switches off to put the starving carrier into prone position ASAP?
Doesn't sound like a bonk.
I've only ever had one. 2006 in Colorado I came to a standstill towards the end of a long hot ride. A kind cyclist stopped and gave me a drink bottle which I promptly dropped and wasted all the contents. Luckily he had a second which he fed me, and I recovered a bit.
He cycled on, and I cycled maybe half a mile before collapsing on to a grassy bank, I must have been there for a good while, I couldn't get up.
So, eventually someone stopped and helped me get back to my wife's sisters house, where we were staying. I collapsed into bed my legs started the worst cramps I've ever had.
Have a cherry.
I am not sure. You have no chance.
It’s the vasovagal version that hit me. I was unconscious for a good few minutes. It was extremely nasty.
I had darkening vision once, at the end of a Fred Whitton. I had a central tunnel I could see ok but the majority of my vision was dark. It was on the flatish run in and I desperately followed a wheel in front as I knew had I lost it I couldnt have cycled safely on a road, I basically relied on the other rider as a guide. Funny thing was I had no loss of power beyond normal fatigue.
I've bonked after 5 miles... day after a big ride... commuted in (12 miles) probably didn't eat enough at lunch or wrong kind of food, bonked on the way home almost immediately
As a member I can vouch for this.
Road - Wilier Izoard Centaur/Cube Agree C62 Disc
Allround - Cotic Solaris
I'm not sure this is correct, the body tightly regulates glucose metabolism, you would need to be very seriously ill, liver or renal failure, diabetic or have an insulinoma before you ran out of glucose.
So when bonking, one runs out of one specific form of sugar, glycogen, which needs energy to regenerate. I.e. eat sugar
The bonk is happening when the body has to switch its fuelling source. If you’re riding at a relatively high intensity ( power and / or HR zone 4 or higher ) the body is going to be fuelling mostly on the easily metabolised glycogen and triglyceride stores from your muscles and liver. If your riding at relatively lower intensity it will have enough time to fuel more from stored fat and top up with a dip into the glycogen stores. If you’re bonking you’ve more than likely been riding at an intensity that has completely emptied the glycogen stores and the body has to do what it can to keep your brain fuelled. The worst case scenario here is that you start producing Ketones which really is emergency fuel directed at the brain. Your breath/ sweat will smell a bit of pear drops if it goes on for too long. Eating something sugary will put the metaphorical fire out but you’ll still need something else more substantial to try and prevent bouncing along from bonk to bonk. If you train right the bonk won’t happen at all and if it does you’ll be so near the end of your exertion that you’ll be able to get to the conclusion by eating something sugary.