First Bonk - Scary.

It’s a really bad experience!
Scary until you realise exactly what is happening. Truly horrible!!

It’s truly awful isn’t it! Usually caused by as you say lack of fuelling, I remember it happened to me on a road ride and I felt so sick I just wanted to lay down, close my eyes and have the ground swallow me up to stop it!

Luckily it went away after a few minutes, but yeah I just make sure I do what I can to make sure it never happens again…

I remember being a mile from home, feeling great one minute then rolling off the bike, leaning against a road sign and thinking I was not going to see home again, truly frightening. I would have killed for a mars bar at that moment. Managed to drag myself home and ate whatever was available.

^^^ that’s exactly my experience. I was training for a half marathon so did a 10 mile run then went out for a twenty mile MTB ride (both without eating). About 18 miles into the bike ride I bonked and actually considered eating some brake pads I had in my Camelbak. I managed to get home and just stood in front of the fridge and ate stuff. Thirty minutes later I was fine 😹

A few hours later I was in Leeds getting pissed and the next day I was fine.

It would take me weeks to recover from that shit now.

It is so hilariously terrible, like combining a diabetic hypo, the flu, a really cold windy rainy day, and a massive attack of depression into a half brick and then getting it thrown at your soul

Amen to that!

Northwind
Full Member
It is so hilariously terrible, like combining a diabetic hypo, the flu, a really cold windy rainy day, and a massive attack of depression into a half brick and then getting it thrown at your soul

You went out with her too?

I bonked 0.5 km from the end of my first duathlon - 10km/40km/5km.

I hadn't trained for the run legs at all, just assumed my cycling fitness would get me through (ah, the folly of youth).

First 10k run was surprisingly ok, 40km cycle I overtook most of the field (they were mostly runners not cyclists), last 5km run I was going ok, but then suddenly felt like I'd done a load of shots. Legs went and I was dry heaving at the side of the road watching everyone re-overtake me 😆 I managed to walk to the finish, but it wasn't pretty!

Had one this year on a really big hike. Always triggered by a sweaty head then legs of rubber.

My first bonk was terrifying too. She was older and much bigger than me.

Last one that springs to mind was beasting myself up Dash Falls, reaching the gate and needing to sit/lie down, feeling nauseous, ****ed and an urge to shit my pants.

First one was back in the 90s, not long into being a 'serious' MTBer. First longish XC ride away from home following a magazine route, probably from MBR. Weird and slightly unsettling mix of utter exhaustion, slightly halluciinatory experience and out-of-bodiness. Made riding through a traveller encampment more than interesting. Somehow made it back to the car and found an open chippy. Never before or since have I consumed so much fat and and sugar in such a short amount of time than at that point. Not sure I was really in any fit state to safely make the two hour drive home...

When i was younger i used to do this all the time not even always when exercising.   Now i always carry jelly babies when on the bike.

I did get to recognise warning signs

With me i just want to sit down and weep when it happens

Happened once to me when running. 16km out to a lake for a swim on a hot day. Half way back I ran out of sultanas and shortly after water. Last 5km was utterly miserable. A dog walker I went past said “You looked ****ed” … I was too rooted to reply, just staggered past as I knew I was close to home.
Only happened on the bike once. Only had a bidon and an apple on me, the apple was too big for my bag so I ate quarter of it. The first part of the route through the forestry had heaps of dead ends, then I did a massive road climb to some dirt roads. On a super fast descent a rock broke my derailleur and I was left with the five hardest gears and a horrific ride through fire breaks in thick rainforest, partly unrideable with a full set of gears. By the end of that, 2 hours behind schedule, I had a 10km road cruise with one steep pinch. I thought I’d made it but after 2kms I bonked. That last 8km nearly killed me… and so did my wife when I finally got home too late to get the kids from school. No bonks given.

This is so timely for me . I've been riding regularly since the mid 90s and I've just had this happen twice in recent weeks. The first time was scary as I didn't know wtf was going on . The next day I thought I'd get advice from a pharmacist like we are advised. The first one was clearly too busy to sit and listen properly told me to see my GP get blood tests because I've probably got Diabetes 😞 

Oh missed the part where I got a 2nd opinion and a different pharmacist  explained Hypoglycemia to me and why it probably happened to me . Didn't learn from that though 🙄 because it happened again last week 🙄

Hunger bonks are bad but dehydration bonks are absolutely horrendous. Sitting there in a complete daze - floating on air sensations with no ability to think why you feel like this  😂

It's happened a few times for me.
I remember cycling to work once in the snow - off road commute along towpaths so I used the MTB. Cycling home that evening I blew up big time climbing past the lock flights. The final 3-4 miles along flat snow-covered towpath took forever, I was weaving around and every slight bump just jarred.

I got into the house and was almost sobbing with relief as I stood in the kitchen, still in all my cycling kit, scoffing down rice pudding direct from the can, cold.
It took a while of raiding the fridge and the biscuit tin before I'd recovered enough to actually consider getting some proper food!

Sounds like a bonk - I used to regularly under fuel, my worst bonk was after a 50 mile road ride with one bottle of water and no snacks on a nice frosty winter morning.  I ended up lay on a verge and scavenging some frosted sprouts from a field.  Made it home, ate a whole jar of jam and then crawled shivering into bed still wearing kit.  Think I was probably a bit hypothermic as well.

I remember a particularly bad one a couple of years ago.

I hadn't been out on the road bike for quite a while and had just been doing shortish local MTB loops and thought I'd smash out a quick 100k on the road like I used to, my body had other ideas. About 15k from the end near the top of a decent climb I just suddenly blew up, I started craving salt and vinegar squares and was almost at the point of searching out empty crisp packets in the verge, legs were like jelly and I just wanted food, any food. I managed another 2k to get to a shop and received some right strange looks whilst buying a couple of tins of coke, mars bars and all other manner of complete shite. Sadly no salt and vinegar squares though 🤣

Now i always carry jelly babies when on the bike.

Haribo for meh,although my current fave is some refresher type thing packed in 2s.
(For in case of emergency)

I always have to remember to drink the full fat coke though on a long day but my fave anti bonk is a nice coffee con leche with the sugar and biscuits you get, works a treat to caffeinate and sugar up.(much nice than the non-pro gel brigade).

I never have sugar in my drinks other than on a long ride, you can burn thru silly amounts of calories.

Your first Bonk is pretty grim, all the ingredients of something medically nasty, then you realise that perhaps burning 1000-1,500calories without stopping to eat may not be a good idea and possibly something you don’t normally do.
(It’s why I giggle when people bang on about fasted training)

I think the big problem is getting the fuelling right for what your activity level is, but the roady trick of the coffee stop is pretty good.

Mine was an MTB duathlon at Llandegla, mate was a faster runner so let him speed off knowing I'd catch him on the bike leg, rode like a madman then got on final run and bang. Never been so relieved to see littered gel wrappers as a grabbed them out the mud and squeezed the dregs out (like zammo in grange hill). Limped to the end and mate had crashed and dnf. Ordered 2 of everything at the café, never failed to fuel property since!

I badly misjudged the severity of the hills in the Trough of Bowland when I first moved to Lancaster in about 2002. Pre-Strava / GPS / smartphone obviously, I'd looked at an OS map and plotted a nice 70 mile road ride around my new patch, bit of a discovery ride.

I'd come from a background of road and MTB racing, I'd done road races that long before (down in the south-east...) with no problems so off I set. Going back to that thread discussing early roadies and gear choices, I was of course on a 39/53 with a 12-23 cassette (that was just what you had at the time!) and, in spite of stopping a couple of times at cafes, I absolutely died a death on the big climb out of the Trough heading back towards Lancaster. I stopped at the side of the road and had the last crumbs of flapjack that I'd saved from my previous cafe stop. I'd run out of water by then too so had nothing to wash it down with but it got me home at a bit of a crawl.

That was a little lesson in "hills up north are a lot harder than the ones down south!"

The stupid thing was that at the far north end of the ride I'd seen a roadsign saying "Lancaster" but as I was completely new to the area and as it was right on the junction of about 3 OS maps (only 1 of which I had with me), I couldn't tell how far or what type of road so I stuck to my original route. When I got home and looked at the full map, I realised that it would have been a simple 15 miles of flat instead of the 30 miles and 4000ft of climbing back through the Trough.

I'm just compiling a list of the best bonk remedies:

Brake pads

Roadside empty crisp packets

Jam out of the jar

Frosted field sprouts

Your not a cyclists unless you've bonked a few times...last time I bonked on zwift I did a race then a ftp test then a group ride.....bonked the last 5 miles from the finish.

It's not so bad on the turbo.....outside tho it really ruins your day.

Can't say I get blurred vision...just zero power and completely drained.....must be different for everyone 

Weak, drained, wobbly wobbly, etc - normally when I'm with 5 miles of home.

On a different note I did get blue lighted to hospital on Friday with a temperature of 41 and going into steroid crisis - that was an interesting ride 😃 

Ohh, I recall another time now - at one of the Welsh trail centres and riding with a group - this time it was a big ride on the second day of a long weekend. Having bonked before (see above) I recognised the signs but I had no food left. Fortunately, a friend had a Marathon/Snickers bar that he gave to me. I can't stand peanuts but, boy, did that peanutty chocolate bar taste good!

It’s almost a rite of passage for any cyclist and a test of fortitude for any beginner to see if they come back for the club ride the next week having bonked on their way home. Had a couple of ride buddies who were adapting to keto and so would inevitably bonk badly near the end of a ride. My best was insisting we stop in the village shop 2 miles from home after a 90 miler 🥴

Riding home as a teenager, after a night out nearby drinking at a friend's house party in the north Lakes. Hangover + bonk = little me sitting on the forecourt of a garage eating the Mars bar and can of coke I'd bought with the little bit of cash I had on me, it not really touching the sides, and the lady in the garage giving me the biggest bar of chocolate they had for free because I looked like I was dying. The last 10 miles home was purgatory...

I know when I'm heading for one. As soon as the only thought in my head is food I know that a bonk is incoming.

I got a feeling of euphoria the couple of times I’ve bonked just before it hits, riding long all dum-de-dum-de-dum this is brilliant type of thing then-wham rug well and truly pulled out from under.

My worst bonk was 430km into a 500km audax. I had ridden from 6am to about midday the following day without any rest and had absolutely nothing left in the tank. I was carrying enough energy bars etc. but had reached the point where I could not eat anything.

I saw a roadsign indicating 10 miles to my home and made the sensible decision to sack it off which in retrospect was sensible as the last stage was on A roads which was no place to be in the state I was in.

Coffee and cake in a garden centre cafe helped a bit but it still took nearly two hours to limp home and It was a few days before I was recovered fully.

That ride taught me a lot and I now plan my eating on longer rides and stick with food that is very easy to digest - no English breakfasts or other stuff that requires too much effort to process.

@pyro  thank heavens for petrol station angels 

I was 16 when I had my first bonk. Been out with the CTC for a few runs and one guy said, you're ready for the chain gang now, I had absolutely no idea what he meant and it was 1986 so it was impossible to find out even what the phrase meant in a week....

So I showed up on a Sunday morning at 8am (after cycling 8 miles to the start point) with my Elswick Stag touring bike with the mudguards taken off and 1 water bottle for the hardest riding I think to this day I've ever done. 

When they dropped me off 50 miles later I literally fell off my bike into a petrol station car park. No money, no energy to even speak.....the last tiny part of me had been enough to say "yes I'm totally fine" as they rode off.....

An angel in the kiosk gave me a bounty bar and a coke for free and asked if I needed a doctor!!!

All I had to do then was cycle the 8 miles home. 

First day of the tour of Wessex, about 85 miles into a 105 mile ride. The day had not gone well for me any way. I was last and not going to make the cut off time and the last feed station had packed up by the time I got there!

I remember feeling like I was going to fall asleep, just started randomly crying and having really bad thoughts, I had a bar of some sort in my pocket but when I tried to eat it I couldn't swallow and thought I was going to throw up.

I knew my wife and kids were going to meet me at the finish line and they would be on their way at that point, so I rang her to see if she could find me and bring me something to eat and drink. I didn't really know where I was but she said she'd try and find me. As I carried on riding I came across a co-op, in Glastonbury I think, so stopped. As I got off the bike my wife came round the corner!

Bottle of coke, half a tuna sandwich, and a couple of chocolate bars and I was on my way again. Came in 30 minutes after the cut off time. Worst I've ever felt on a bike!

I liken it to the first time you actually get Flu.

Many people think they have had flu. Until the one time you actually get flu, and you realise all the previous times were just a nasty cold.

Ditto the bonk - suddenly all the previous times I was 'just pretty worn out and tired' compared to the absolute terror of feeling like I was no longer in charge of my own body and destiny, and that this was an actual bonk, and it might be the end of me. Literally sat in a ditch, no food, no water, and hope that text message to come rescue me had gone through to my partner!
Awful, never again I hope!

I can't remember the first, but it was a fairly regular thing when I was younger, or at least getting to the point where you just about made it home before bonking. But miscalculate that and yep, been sat in a bus stop 2 miles from home wondering if I can make it or should call for help.

The worst I remember was on a MTB ride in Exmoor. It was fab riding and I thought I'd got it about right, only 3 or 4 km to do - but that was out of Porlock and up a sapping hill and the engine light came on big time.....I was condiering phoning my mummy despite being over 40 years old and 200 miles from home (she'd have come too). I was licking the drips off the outside of used gel wrappers, looking in the bin at the bus stop in case there was anything calorific in there.

The next year (it was a regular trip) I was wise and saved a caffeine gel which I sucked down in Porlock and was spinning and chatting like a good'un. Then someone clipped a rock, got a puncture and I was just feeling this excess energy ebbing away while we fixed it. Set off.....and on comes the engine light again.

I now save 2 emergency gels for big rides!

Welcome to the world of the T1 diabetic. No matter how careful you are there are times when it just goes **** up. 

Crikey, I thought I’d bonked before but never had any of the symptoms mentioned above 

usually I just grind to a halt, my power drops off a cliff within a few minutes, and I pedal very slowly home feeling sorry for myself

blurry vision, that sounds terrifying!!

On the other hand, watching it happen to a mate is fhecken hilarious.
One friend bonked on a ride in the middle of wales. A normally fit and fast lad. I think he was run down for a couple of weeks of constant sport / training each day. He couldnt even open the wrapper of a mars bar one of us had given him, he was so fhoooked. I told him he'd have to eat it with the wrapper one then !(good mates, eh). After getting back to the accom he was completely wasted for day and remainder of the weekend.

Another (different) mate repeatedly never learns (which is amusing as he's a lecturer with a PhD). He's always off like a rocket..100 mile an hour dog. Red Line or bust. Usually bust ! He blew up about 3 miles from the end of a 115 peaks road ride after smashing it off the front all day. And another 100 miler where someone in the group had to cirle back to find him outside a co-op lying on his back on a bench pouring a family size bag of Haribo from the shop down his gullet. A further big ride day where he got less than 2 miles from home and had to hit the Morrisons petrol station where he then gorged himself senseless on Ginster's finest provander (he was an hour late home from that and missed taking his daughter to a dance class... i think he was turned into eunuch bynhis Mrs when he did finally get home with him and his bike in someone else's car.
The one time he was absolutely adamant he wasnt going to blow up, he had 3 large slices of cake at a cafe... then spent the next hour regreting it as he was constantly on the edge of puking.

Happy days.😎

I don't think I've ever properly bonked, but I came close...lost the will to live, couldn't turn the pedals any more despite not being out of breath or anything...felt a bit dizzy..that was about 75 miles into a 95 mile ride...

Same old story, not refueling before I felt the need to refuel, but by then it's too late.

A couple of ham and cheese sarnies and an energy gel, during a 45min sit down and rest, and I was ok to carry on.

Does anyone remembers the Enduro6 6 hour MTB event at Trentham Gardens?

I did well in the first one, coming in just outside the prizes, which were pretty substantial. 15th place prize was a Kahuna watch. (Again iirc!) I entered the second year, and changed my tactics - I'd carry more food and eat while riding, spending less time in the pits, and try to ride through before the 6 hours were up, so making an extra lap. If I had done that the previous year, I'd have been in the prizes.

All good, I went off like a rocket, and after several laps was in the prizes just behind the pros. Then riders started to pass me, which was odd, because I wasn't slowing or feeling weak, so I upped my pace a bit. And more riders passed me, so I pressed on a bit more, and after about 3 hours blew up completely, limped back to my pit, consumed 1000s of calories and went to sleep for an hour. I rode a final lap, very slowly, just to finish the event on the bike, and ended up a way down the field.

The first year had been entirely 6 hour solo riders and I hadn't realised that team entries had been allowed for the second event, so the riders I was trying to keep up with were completely fresh and part of a duo or team of four! Always read the event detail carefully! 

Horrid feeling isn't it. I had a few when marathon training back in the days when I could run. I can remember feeling exactly as you described. I think it has happened once on a MTB ride due to zero fuelling, but running more often, don't want it again.

Does anyone remembers the Enduro6 6 hour MTB event at Trentham Gardens?

I did a few of those, always as a Pair. Had a second place in Mixed Pairs one year and somewhere along the line (maybe the same race!) won a Kahuna watch and courier bag.

I remember being really careful about food, took a well-packed coolbox of everything we'd need. And then I forgot the cutlery. Had to open a can of rice pudding with the tin opener on my Swiss Army Knife and eat it using a tyre lever because the cutlery was in the car - which I could clearly see from the pits.

Very annoying.

In a related race (Pairs at 24hr SITS, Catton Park) I managed to judge it to perfection and ride myself to the finish on the final lap, collapsing just after I'd crossed the line. We were in line for 2nd place and I had to keep the chasing team at bay, I knew I was running low after my final gel on the previous lap but just had to keep pushing. The final descent I was all over the place but I just about held onto it all. Literally blowing up as I crossed the line.

I managed to judge it to perfection

Unlike an event (on Salisbury Plain?) where I was chasing a place in the top 5 (maybe?), grabbed a gel from my pocket to cover me for the last few miles, went around the corner as I unwrapped the gel and rode straight under the finish line. 😀