Bonk?

marcusww

Having not cycled for 3 weeks I went on my occasional club ride yesterday and really suffered at the end. We did 55 miles 3200 feet at 17 mph av. which is fast for me but riding with people helps a lot. After having 2 crumpets and half a bowl of porridge in the morning I had 1 gel and 1 banana during the ride. Going home was awful I could only just stay on the bike - going up a steep but short 50 yard hill and down to 1st gear in many places. In the past when doing sportives of 60 miles plus I would have eaten a lot more.
Having not knowingly experienced 'bonk' before is this it? Is the food I took too little?

bails87

Sounds like a 'yes' to both of those questions. Horrible, isn't it?

marcusww

yes every pedal stroke was a killer, definately learnt a lesson!

djm501

I would definitely say no.

First of all though - nice ride and good speed 8)

However, the bonk is akin to 'hitting the wall' in Marathon running - given that you only rode about twice the distance of a marathon and if there is a bike equivalent then it's generally 4-5 times the distance of running then you haven't gone nearly far enough for this. You eat plenty also.
What you describe I would regard as being just very very tired.

I had to go to 400 km distances before I started discovering what bonking was really like - and even then I'm not sure I've truly experienced it. The long distance cyclists I hang out with talk of riders literally riding into the back of parked cars, into ditches with the potential to just fall off in front of cars. It's in the 400 km - 600 km range where bonking is a real danger. When the bonk hits you have close to zero blood sugar and your brain stops working properly due to lack of energy.
On a ride under 60 miles I wouldn't bother eating anything because you don't need to.

This is a video of (admittedly runners) 'bonking'
http://www.youtube.com/watch?v=LKf1eTzmK14

saprkzz

djm501 wrote:

I would definitely say no.

First of all though - nice ride and good speed 8)

However, the bonk is akin to 'hitting the wall' in Marathon running - given that you only rode about twice the distance of a marathon and if there is a bike equivalent then it's generally 4-5 times the distance of running then you haven't gone nearly far enough for this. You eat plenty also.
What you describe I would regard as being just very very tired.

I had to go to 400 km distances before I started discovering what bonking was really like - and even then I'm not sure I've truly experienced it. The long distance cyclists I hang out with talk of riders literally riding into the back of parked cars, into ditches with the potential to just fall off in front of cars. It's in the 400 km - 600 km range where bonking is a real danger. When the bonk hits you have close to zero blood sugar and your brain stops working properly due to lack of energy.
On a ride under 60 miles I wouldn't bother eating anything because you don't need to.

This is a video of (admittedly runners) 'bonking'
http://www.youtube.com/watch?v=LKf1eTzmK14

really????? There is a set distance that applies to EVERYBODY whether you bonk nor not? or have i mis understood you!! Someone who rides up to 60 hasnt bonked, and you wont need food up to 60 miles.. please tell me you are on a wind up!! please also tell me you are not a personal trainer or anything to do with sports advice!!

diamonddog

+1^ Having hit the wall when a regular marathon/half marathon runner :roll:

djm501

No of course there isn't a set distance - what I was trying to get at was that there are far too many threads around here where people mistake lack of fitness/being tired for bonking. What I quoted was my own experience and what I've heard from a lot of the (very experienced) distance riders I ride with. To be fair we don't tend to do the really high intensity riding that pros do - but then neither I suspect does the OP. Also I have read similar from people on this forum I respect.
The ride the OP describes is neither that long, contains that much climbing nor super speedy - I don't think it was bonking - just being tired. Nothing wrong with that, just get fitter. He also ate a good breakfast and had a gel and a banana - are you saying that's not enough for a 55 mile ride?

From the wikipedia entry on bonking http://en.wikipedia.org/wiki/Hitting_the_wall
'Such fatigue can become seriously debilitating; in cycling, exhaustion can reach the point where the cyclist is unable to stand without the support provided by the bicycle. Symptoms of depletion include general weakness, fatigue, and manifestations of hypoglycemia, such as dizziness and even hallucinations. This condition will not be relieved by brief periods of rest.'"
This is what I understand as bonking - maybe others' definitions vary. I have definitely had huge drops in energy output when cycling long distances which were cured by eating energy rich food but I've only once got to the extremes of hallucinating (I think - can't really be sure if I was hallucinating or not - it was very weird and I was probably sleep deprived too).

diamonddog

djm501: From the wikipedia entry on bonking http://en.wikipedia.org/wiki/Hitting_the_wall
'Such fatigue can become seriously debilitating; in cycling, exhaustion can reach the point where the cyclist is unable to stand without the support provided by the bicycle. Symptoms of depletion include general weakness, fatigue, and manifestations of hypoglycemia, such as dizziness and even hallucinations. This condition will not be relieved by brief periods of rest.

The key word throughout the above is CAN, bonking or hitting the wall will have varying levels of the above but as can be seen in the pro tours it is not always to the max and it is possible to take on the fuels required to keep going, not all cyclists or runners suffer to the same degree every time they bonk or hit the wall.

Mikey23

Having not ridden for three weeks it might have been quite a high intensity ride for his level of fitness and caused by a combination of conditioning and energy loss or perhaps dehydration. I've bonked in marathons and although it wasn't pleasant, I could continue at a kind of painful shuffle and I think in my case underestimating the amount of fluid I needed to take in

djm501

Fair enough - still think he was just tired though - 3 weeks off the bike before won't do much for your fitness or conditioning but it probably will help those glycogen and fat stores

I posted on a thread about this a couple of months ago when someone was wondering whether they'd bonked after an 80 odd mile ride. I was the one agreeing with him then and others were shooting him down in flames saying you'd need to ride at least 100 miles beforehand. How times a change. :?

diamonddog

djm501 wrote:

Fair enough - still think he was just tired though - 3 weeks off the bike before won't do much for your fitness or conditioning but it probably will help those glycogen and fat stores

I posted on a thread about this a couple of months ago when someone was wondering whether they'd bonked after an 80 odd mile ride. I was the one agreeing with him then and others were shooting him down in flames saying you'd need to ride at least 100 miles beforehand. How times a change. :?

We all have different views stick to what you believe

chrisaonabike

saprkzz wrote:

really????? There is a set distance that applies to EVERYBODY whether you bonk nor not? or have i mis understood you!!

I think the only thing you've misunderstood is how little imagination a lot of stronger riders have.

It's always the muppets that can ride super fast, for super long distances, up super-steep hills, etc etc, that have completely forgotten the fact that there are lots of people that can't do those things.

They get right on my t!ts - I already know I'm slow, I don't like constantly being reminded

djm501

I've been riding for just about 15 months and I'm not super speedy. Being totally unfit before May 2012 i have forgotten nothing. The ride the OP describes I could do at that speed I think but not much faster. I have graduated to very long rides I'll grant you. 600 km is my current max. It's gratifying that you think I'm one of the stronger riders though, not sure I'd agree.

I think the point may be that until you _can_ do longer and/or very high intensity rides then you won't get near to experiencing bonk. What you will encounter instead is getting very very Knackered. Not the same thing.

drlodge

djm501 wrote:

I've been riding for just about 15 months and I'm not super speedy. Being totally unfit before May 2012 i have forgotten nothing. The ride the OP describes I could do at that speed I think but not much faster. I have graduated to very long rides I'll grant you. 600 km is my current max. It's gratifying that you think I'm one of the stronger riders though, not sure I'd agree.

I think the point may be that until you _can_ do longer and/or very high intensity rides then you won't get near to experiencing bonk. What you will encounter instead is getting very very Knackered. Not the same thing.

Its a bit like having a thread called "Migraine?" and everyone talking about their bad headaches.

djm501

indeed

pinarellokid

so when does very very tired become a BONK then??

i think the people you ride with have changed the way you think compared to most cyclists fella. 600km !!!!!!!!

that distance most people will never ride i would bet.

the playing mantis

i think the key is how did you recover? that would distunigish it between general tirdness and genuine bonking!

i think its not correct to say bonking only occurs over long distances. if you take no fuel and do high intensity over a short /medium distance the same feelings, dizziness, lack of power, decline in spatial awareness etc. can occur

i have experinced this when not pre fuelling on a couple of 40 mile rides, after 30-35 i couldnt go on safely, i felt dizzy and un safe on the bike. both times i had to call in, the first time i didnt eat/drink anything for sometime and the symptoms only went when i did.

the 2nd time went straight to a corner shop and bough a bottle of lucozade, downed it, and within 5 minutes i felt perfectly fine again, and had i not been picked up, could have comfortbaly carried on on the bike as per normal (obviously with taking on a bit more fuel as i went)

djm501

pinarellokid wrote:

so when does very very tired become a BONK then??

Bonking is when the body gets utterly deprived of blood glycogen and other short term energy reserves and can no longer function properly. It is manifested in a _sudden_ loss of energy and other syptoms of hypoglycemia as I posted above. Being knackered is a different thing - muscles can't cope with the demands put on them, your cardiovascular system can no longer work to the level you are asking of it - but your blood sugar levels are just fine. This is lack of fitness/body conditioning, not bonking. You will get fatigued of course but the onset is more gradual and probably accompanied by muscle pain. I've definitely (every time!) been knackered to the bones on and after long rides (we call them audaxes) - I'm really not sure if I've bonked. Maybe once, like I said.

pinarellokid wrote:

i think the people you ride with have changed the way you think compared to most cyclists fella. 600km !!!!!!!!

that distance most people will never ride i would bet.

Well I've only done it (600 km) once but I plan to continue - it's fun and a real personal achievement! The audaxing crowd is certainly different I'll give you that. The real nutters just did London-Edinburgh-London - at 1400 km my 600 is a cakewalk in comparison
Bonking is something we really have to think about once you go to the real long distances so I guess we have to pay attention to it more than most. Most audaxes I do are 200 km (126 miles). I wouldn't worry about bonking on a 200 - not going to happen unless you're foolish and eat nothing at all. I regularly ride 60-80 mile rides in the weekends I'm not audaxing and rarely feel the need to eat more than maybe half an energy bar, usually I'll eat nothing although I do make a couple of isotonic drinks. My typical weekend ride is a 72 mile run through the South Wales valleys and is about 5000 ft in total climb. Best speed I've managed on that is about 15 mph average so nothing to write home about. A good breakfast and reasonable carb load is definitely (essential) a good idea beforehand mind.

the playing mantis

so in answer to the ops question, we need more info.

chrisaonabike

djm501 wrote:

I think the point may be that until you _can_ do longer and/or very high intensity rides then you won't get near to experiencing bonk. What you will encounter instead is getting very very Knackered. Not the same thing.

Well, you may be right, however, on the occasions where I didn't eat early enough during my 40-50 mile rides, I did experience something very strange - as I mentioned, I wasn't taking in information in front of me, I felt weird, kind of spaced out. The riding was a lot slower and harder, but I wasn't out of breath.

I definitely was not knackered, and the weirdness went away (leaving me full of energy again and absolutely fine), within a few minutes of stuffing some flapjack down my face.

I've had blood tests in the last couple of years, I'm definitely not diabetic; I can only think that the symptoms were very early signs of glycogen depletion.

Don't people get able to store more glycogen as they get fitter? Maybe it's just that people new to it all, as I was at the time, are more susceptible to getting low on glycogen reserves.

djm501

viewtopic.php?f=40020&t=12919045&p=18293195&hilit=bonking#p18293195

viewtopic.php?f=40020&t=12919240&p=18289217&hilit=bonking#p18289217

viewtopic.php?f=40020&t=12917598&hilit=bonking

viewtopic.php?f=40013&t=12921768&p=18317070&hilit=bonking#p18317070

viewtopic.php?f=40013&t=12919405&p=18290480&hilit=bonking#p18290480

Just some of the previous threads on this topic. Much information there

Mikey23

Lots of stuff online. Just google the science behind aerobic and anaerobic fitness. Most of it directed to the running community but much applies to cycling... I'm a level 2 UKA coach specialising in endurance btw

ct8282

I've bonked before, back in my MTB days. Was at the back end of a 30 odd mile, very intense and hilly off road ride. It was scorching hot and I was nowhere near hydrated enough and was exhausted. We were climbing an extremely brutal and long hill, and I was pushing hard. About 100 yards or so from the top I literally just lost everything I had. I stopped and put my feet down, went extremely dizzy, felt very nauseous and faint and was struggling to keep myself upright. My friend had to help me off the bike as I literally could not raise my leg over the frame.
I had to lay down and really thought I was going to be sick, my hands were shaking and I was not in good shape at all. However, I took on some fluids, put down a cereal bar and within about 15 to 20 mins I came round, we set off again and I managed the 4 or so miles home, gently.

The closest thing I can relate to it was when you green out after doing one too many bong hits! I'm sure some of you know what that's like, and of course I haven't touched any of that shite since I was 17, but its the closest thing I can think of, that or being really sick from being way too drunk perhaps.

amaferanga

To suggest that you can't bonk unless you ride 200km or even 400km is absurd. It's probably possible in no more than 3 hours depending on how hard you ride and whether or not you're glycogen depleted before the ride. Probably takes a bit longer for your average bearded audax rider though since they're so slow.

pinarellokid

riding above your game will quickly deplete your energy levels leaving you in trouble.
i personally get a banging headache if the pace is too high for me, that happens to everyone im sure

sbbefc

Ive bonked twice, once on my first 100km + ride where I only had a coke half way through, no bananas or gels or anything and only one bottle 750ml of water. So I was probably dehydrated more than anything else. Second time was when I rode my road bike to a mountain bike centre, did one lap and a half of the course and totally conked out (only about 50ish km). Again, not enough water or food.

I've done rides and felt very tired at the end but nothing like that, I was delusional and all over the place. Just drink enough and take enough food and its fine.

Rigga

Question re: brekkie.. beans on toast with poached eggs or a bowl of fruit and fibre?

This is before a blast round dalby forest on the mtb.

Dmak

My place or yours?

I've bonked twice. I normally have a litre of good squash in my bottle which helps but on a longer ride I carry some chocolate or some flapjacks.

IT IS HORRIBLE.

Dmak

pinarellokid wrote:

riding above your game will quickly deplete your energy levels leaving you in trouble.
i personally get a banging headache if the pace is too high for me, that happens to everyone im sure

Sometimes, although I put it down to not drinking enough fluid before the ride.

DavidJB

ChrisAOnABike wrote:

saprkzz wrote:

really????? There is a set distance that applies to EVERYBODY whether you bonk nor not? or have i mis understood you!!

I think the only thing you've misunderstood is how little imagination a lot of stronger riders have.

It's always the muppets that can ride super fast, for super long distances, up super-steep hills, etc etc, that have completely forgotten the fact that there are lots of people that can't do those things.

They get right on my t!ts - I already know I'm slow, I don't like constantly being reminded

I've not done it properly for about a year but it still happens even if its due to over training or illness or whatever. There's nothing worse than being 30 miles from home and barely being able to turn the pedals...every 1% rise feels like an alpine pass, every mild head wind gust feels like a hurricane and all you want to do is stop riding but you will not be defeated! You get home and proclaim you'll never ride again and then the next day go out for 4 hours of intervals.

There were two times it's really happened badly.

Once I went out with the flu on the 'fast club run' got round 40 miles with no issues then boom I was crawling back for the last 15 miles at maybe 12MPH and had to get off and walk up this tiny hill because I just couldn't do it.

Second time I'm not sure why it happened, turned into a headwind that was a headwind for 25 miles, bonked right away and again crawled home, almost started crying at one point and went a bit nuts.

You get over it though and apart from the flu one I was on the bike the next day raring to go!

pinarellokid

lol like the comment you'll never ride again..
most iv left the bike alone is 4 days after a bad ride.
never seems as bad the next day luckily..