Finally joined the bonking club

lettingthedaysgoby

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

kingstonian

haha, it isn't a great experience is it !!!

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 !!!!!

fenix

I do it every couple of years on one of the first longer runs of the year. Never done it at 30 miles though.

BikerGroveish

The worst bonk I ever encountered landed me in the back of an ambulance care af a reflex syncope.

https://en.m.wikipedia.org/wiki/Reflex_syncope

That’s as bad as I’ve ever experienced.

lettingthedaysgoby

Fenix wrote:

I do it every couple of years on one of the first longer runs of the year. Never done it at 30 miles though.

Yeah, that was the weird bit. I’d been reasonably pushing it for me (average of around 18.5 mph, which is at the upper end of my usual speeds) but pretty much without warning it all went wrong. Stood up on the pedals for a climb and bang, nothing there.

Ah well, made it to the cafe and ate ALL THE FOOD which seemed to cure things.

ugo.santalucia

I've learnt to feel it coming before it's too late... it normally develops quickly from that point to the point of no return

sloppyschleckonds

A bonk after 30 miles?

lettingthedaysgoby

SloppySchleckonds wrote:

A bonk after 30 miles?

Seemed to be. Was a bit weird.

sloppyschleckonds

lettingthedaysgoby wrote:

SloppySchleckonds wrote:

A bonk after 30 miles?

Seemed to be. Was a bit weird.

Did you get off your bike and lay down on a grassy verge somewhere?

N0bodyOfTheGoat

lettingthedaysgoby wrote:

SloppySchleckonds wrote:

A bonk after 30 miles?

Seemed to be. Was a bit weird.

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.

mamil314

BikerGroveish wrote:

The worst bonk I ever encountered landed me in the back of an ambulance care af a reflex syncope.

https://en.m.wikipedia.org/wiki/Reflex_syncope

That’s as bad as I’ve ever experienced.

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?

joe2008

lettingthedaysgoby wrote:

Stood up on the pedals for a climb and bang, nothing there.

Ah well, made it to the cafe and ate ALL THE FOOD which seemed to cure things.

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.

pblakeney

Well done!
Have a cherry.

mamil314

Joe bonk usually is manifestation of running out of sugar. Most people would recognise it from loss of power, darkening vision and/or clear thinking issues. Downing a gel or a snickers bar should perk you right up in 5 to 10 minutes, if not restoring normal power. Your case seems more dangerous like severe dehydration/electrolyte loss

BikerGroveish

mamil314 wrote:

BikerGroveish wrote:

The worst bonk I ever encountered landed me in the back of an ambulance care af a reflex syncope.

https://en.m.wikipedia.org/wiki/Reflex_syncope

That’s as bad as I’ve ever experienced.

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?

It’s the vasovagal version that hit me. I was unconscious for a good few minutes. It was extremely nasty.

DeVlaeminck

mamil314 wrote:

Joe bonk usually is manifestation of running out of sugar. Most people would recognise it from loss of power, darkening vision and/or clear thinking issues. Downing a gel or a snickers bar should perk you right up in 5 to 10 minutes, if not restoring normal power. Your case seems more dangerous like severe dehydration/electrolyte loss

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.

cycleclinic

what the hell did you join this club for. its a shit club and remember not to demand a refund.

ugo.santalucia

SloppySchleckonds wrote:

A bonk after 30 miles?

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

lostboysaint

thecycleclinic wrote:

what the hell did you join this club for. its a shoot club and remember not to demand a refund.

As a member I can vouch for this.

orraloon

mamil314 wrote:

...Most people would recognise it from loss of power, darkening vision and/or clear thinking issues...

Agreed. Learned my lesson last year, a circuit I'd ridden many times before. Lights went out. Focus went to 'get home'. In so doing, cycled past open shop where could have grabbed instant sugar rush, and even followed my normal route rather than going directly home. Clearly not clear thinking. Now keep emergency gels just in case.

FatTed

mamil314 wrote:

Joe bonk usually is manifestation of running out of sugar. Most people would recognise it from loss of power, darkening vision and/or clear thinking issues. Downing a gel or a snickers bar should perk you right up in 5 to 10 minutes, if not restoring normal power. Your case seems more dangerous like severe dehydration/electrolyte loss

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.

FatTed

I think you mean muscles run out of Glycogen

mamil314

eesh, OK

So when bonking, one runs out of one specific form of sugar, glycogen, which needs energy to regenerate. I.e. eat sugar

BikerGroveish

mamil314 wrote:

eesh, OK

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.