The dreaded "Bonk" ?
Author
Discussion

nammynake

Original Poster:

2,658 posts

202 months

Sunday 19th February 2012
quotequote all
Guys, I know there are a few serious riders who frequent this forum, so just looking for a bit of advice. I've done a lot of searching on the web but there doesn't seem to be a consensus.

I did a 55 mile road ride today (solo) with about 3600ft climbing. My Strava app recorded a moving time of 4h6m (averaging 13.5 mph - don't laugh!). First couple of hours were OK, felt a bit tired but nothing to worry about. The 2nd couple of hours I gradually got worse. I felt OK on the flat sections but the route was pretty hilly (including a Cat 3's and 2 Cat 4's) and these really did me in. I got to the point on a couple of the steeper climbs where I could barely keep the bike moving (I'm talking probably 5mph). I have a 34/50 chainset and 12-25 cassette I think, so no excuses there. It was a mental battle (stubborness) to keep riding, and I was pretty close to getting off and resting for a minute, which I never do.

Does this sound the like the dreaded "bonk" people speak off, or should I just MTFU?

Anyway the main reason for my post was around food/liquid intake on a ride of this length (time). I had 700ml of water and 500ml isotonic (so 1300ml in total). I finished these about 3.5 hours into my ride (I was probably preserving them rather than drinking when I should). In terms of "food" I had a slice of maltloaf after about 1 hour, an energy-gel sachet thing after 2 hours, then probably about 20 jelly babies in the last hour and a half.

How does this compare with your food/liquid intake on such a ride? I've only been riding road bikes since last Spring - I mostly do MTB rides but never feel this st on MTB rides, even when out for 7+ hours.

Sorry for the long (and no doubt boring) post, just looking for some advice, as I've foolishly signed up for the Fred Whitton this year, and I'm stting myself !

prand

6,244 posts

225 months

Sunday 19th February 2012
quotequote all
nammynake said:
It was a mental battle (stubborness) to keep riding, and I was pretty close to getting off and resting for a minute, which I never do.
Compared to my experiences of the bonk, your description above amuses me a great deal! I usually need a fair bit more than a minute rest (sit down for 10-20 mins or so!), comically unable to hit any hill beyond a gentle slope!

I would say that for the long distance, high intensity stuff you describe, you have not taken on enough fuel, before or during to maintain the effort over such a period.

My solution is to either prepare, eat well before, and keep refuelling as you go along, or if it hits unexpectedly, stop at a shop and have can of coke and a mars bar, or top up on an energy bar, or any complex carbs to give a bit of slow release and a strong energy drink/fluid to get absorbed quickly in the body.

I'm usually amazed by the quick transformation - power comes back to the legs and ability to get home returns pretty quickly once you get some sugar on board.


Rouleur

7,415 posts

218 months

Sunday 19th February 2012
quotequote all
I've only had the bonk once and believe me if it happens you know about it! You say you were barely moving on the steep stuff but if you bonk you virtually stop on the flat. It happened to me over 20 years ago, and the fact that I can remember it tells you something...

Other guys on here know more about nutrition than me but I'd suggest you take 750ml of water and the same of whichever energy drink suits you, plus the malt loaf or perhaps something like Kellogg's Elevenses bars and the jelly babies. Gels are more for races where you want to be able to get energy ASAP without messing around with chewing.

Also maybe take a break for 5 minutes after the halfway point, it can make a big difference and give you a second wind if you're struggling.

What did you eat in the morning, and the day before?

Oh, and you can't really compare MTBing with road riding as offroad it's more stop-start and less intense.

VinceFox

20,566 posts

201 months

Sunday 19th February 2012
quotequote all
Use some 1" masking tape to tape an emergency snickers to the frame with the mentality of "in case of emergencies, tear off". Use only as a last resort.

anonymous-user

83 months

Sunday 19th February 2012
quotequote all
For me, symptoms of a bonk are: weird tingly feeling in my quads; weird feeling that when I am supposed to be using my quads, the muscle tissue has disappeared; sense of having am vacuum in my stomach; light headedness bordering on dizziness; a feeling around my back teeth that I can't describe very clearly. A bonk comes on quite suddenly. ETA: as others have said, a bonk is like a total system shutdown. You feel weak as a kitten even on the flat.

Conversely, muscle/general physiological fatigue feels like a battery dropping in power, slowly and relatively evenly. That's a fitness/stamina issue. That sounds a bit more like what you describe.

The comment I'd make about your nutrition is on timing (bear in mind different things work for different people). For a 3-4 hour ride I would eat a mouthful of something every 20-25 minutes whether I am hungry or not. I have found that if I wait until I feel hungry, I have waited too long. You should also consider what you're eating. Cake and sweeties aren't great -sugar rush stuff. I swear by clif bars, which contain a mix of stuff incl molasses and oats, and are quite slow release.

I use the same timings for swigging an electrolyte drink. It's probably less important at this of year, but I have found that losing salts (not the table salt variety) will eventually lead to some pretty unpleasant consequences.

Edited by anonymous-user on Sunday 19th February 21:50

nammynake

Original Poster:

2,658 posts

202 months

Sunday 19th February 2012
quotequote all
Rouleur said:
What did you eat in the morning, and the day before?
Day before - porridge for breakfast, sarnie for lunch, then pasta with sauce and garlic bread for dinner, plus a few snacks during the day. For breakfast today before the ride I had porridge, two crumpets with nutella, cup of coffee and some cranberry juice.

MadDad

3,835 posts

290 months

Sunday 19th February 2012
quotequote all
The good news is it does not sound as if you have bonked, seriously - you would know about it!

I have only bonked once (despite having 2 kids) and it is the single most painful thing I can ever remember! Your muscles feel as if they have been filled up with boiling fat, your legs will not move and nothing you do helps - as it came on I went to put a foot down and my leg cramped, I fell off and could not stand up, lie down, kneel or do anything - I think I even cried! I managed to wheel my bike about a mile down the road to a garage, almost crawled in and gulped down a large Lucazade, mars bar and flap jack, within 5 mins I was back on the bike but far too fatigued to continue the ride at the same pace, so limped the last 15 miles across the South Downs to the in-laws.

My experience happen a couple of years ago when I first go back into cycling, I was on a 60 mile ride on an MTB with slicks and it happened about 45 miles into the ride. In hindsight I realise I was not fit enough to undertake the ride and was ill prepared in terms of food, I think I took a couple of banana's, a couple of mars bars and a litre of ribena in a backpack!

Two years on an my body has a much better LT, but I have also learnt to eat properly! The type and volume of 'fuel' you need will depend on the type of riding you do, the frequency you ride/train, and the time of year. There is a lot of science behind this stuff and what you need to take on will depend on how long you spend in various heart rate zones. Without getting too scientific and answering your original question; on a 50-60 mile ride I usually have a decent bowl of porridge a banana, I don't have anything special the night before. On a 50 mile ride this time of year I will usually take a hydration drink and a carb drink and a couple of flapjacks (just in case), but rarely use more than half a bottle of either of them - on a warm day in the summer I will probably finish them both off.

There are so many other factors that can impact what you need to take on, your cadence (spinning is much more effective than grinding), your bodies recovery rate, your personal LT! It's difficult to give the right advice but I would say start with shorter rides and build up your stamina and bodes ability to recover, carb drink and hydration drink work for me along with high carb food (flapjacks etc), I always have a bag of jelly babies in my pocket for the big hills!

As for the phycological element of wanting to give up, I usually back off for a bit, give myself a chance to recover and then dig in again! If its a really nasty long climb then I focus on keeping my cadence high and don't look further then 20 ft ahead of me, never know how much further I have to climb so its always a nice surprise when I get to the crest of the hill!

Long Drax

744 posts

199 months

Monday 20th February 2012
quotequote all
Greg66 said:
For me, symptoms of a bonk are: weird tingly feeling in my quads; weird feeling that when I am supposed to be using my quads, the muscle tissue has disappeared; sense of having am vacuum in my stomach; light headedness bordering on dizziness; a feeling around my back teeth that I can't describe very clearly. A bonk comes on quite suddenly. ETA: as others have said, a bonk is like a total system shutdown. You feel weak as a kitten even on the flat.

Conversely, muscle/general physiological fatigue feels like a battery dropping in power, slowly and relatively evenly. That's a fitness/stamina issue. That sounds a bit more like what you describe.

The comment I'd make about your nutrition is on timing (bear in mind different things work for different people). For a 3-4 hour ride I would eat a mouthful of something every 20-25 minutes whether I am hungry or not. I have found that if I wait until I feel hungry, I have waited too long. You should also consider what you're eating. Cake and sweeties aren't great -sugar rush stuff. I swear by clif bars, which contain a mix of stuff incl molasses and oats, and are quite slow release.

I use the same timings for swigging an electrolyte drink. It's probably less important at this of year, but I have found that losing salts (not the table salt variety) will eventually lead to some pretty unpleasant consequences.

Edited by Greg66 on Sunday 19th February 21:50
That's what I call the bonk. My vision started to go a bit fuzzy, too.
It only happened to me once. Very weird sensations. I was so worried
I'd pass out and fall into the path of a vehicle, that I had to take
a break every 500 yards to regain a fleeting composure.

I was very poorly prepared for the ride and, had no food or water.
Very silly. Won't ever make that mistake again.


racerbob

270 posts

209 months

Monday 20th February 2012
quotequote all
i agree with most of the others, it doesn't sound like you 'bonked' to me. You ate well beforehand which is the important thing. How many rides of a similar distance / difficulty have you done before this last one ? It may just be a question of this ride just being a tad too difficult for you at this stage, depending on what sort of rides you have done previously, maybe you just need to get a bit fitter and then try this one again.

I will always remember my first experience of 'bonking', I was 85 miles into a 100 mile ride, I was 15 and had no money and no food or drink left, the feeling of neausea was incredible, I was wobbling along at about 5 mph completely shot, then, I spotted an apple that someone had taken one bite out of and thrown in the gutter ! I just had to eat it, it wasn't enough of course, but mentally at least it helped get me home, never suffered as bad as that again, been close a few times, but have always had money to ram chocolate bars down to stop it getting that bad again.

good luck and keep trying.

anonymous-user

83 months

Monday 20th February 2012
quotequote all
VinceFox said:
Use some 1" masking tape to tape an emergency snickers to the frame with the mentality of "in case of emergencies, tear off". Use only as a last resort.
keeping things as a "last resort" usually means you finish the ride without having used them as you wil lalways fool yourself into thinking that you are in a better condition than you think you are really in. its human nature to put off eating anything that you have mentally labelled as "emergency".

you will look at it and think "i'll have that in five miles" then five miles down the road think "actually i'm ok, i'll wait a few miles...." and then you are home and there is no point taking it or worse still you fall off at the side of the road in a heap...

trophies

239 posts

221 months

Monday 20th February 2012
quotequote all
Last Saturday for the first time I went out with a riding club. It was around 20 miles off road, most of it snow covered, but very ridable apart from a couple of steep hills.

At around the halfway point we stopped at a tea room where I had a chocolate cake and orange juice. At this point I was ready for a little rest, but also confident that the rest of the ride would be no problem.

With in a mile of setting off I was in trouble. We hit a very slight hill and I couldn't do it. I didn't have the legs to push the pedals. Once the going levelled out, the plan was to compose myself and push on, mind over matter. The next thing I couldn't pedal on the flat. I had to stop. At this point my friend who was with us fell off on some ice, so while he was checked over I had my chance for a rest with out being questioned! After 20 minutes we set off and I was no different. The guy leading the ride knew I was in trouble. I apologised, explained that normally I can do 20 miles, no problem. He said, I had bonked, and that he doubted it was fitness, probably lack of food. The guy was great we slowed down and he got me back to where we set off, but it took along time!

At points I couldn't see sraight, my thighs felt heavy and for a moment my bike felt like 2000kgs.

When I got home I worked out what I had eaten. On the Friday day, I had a cheese roll and 1/3 of a horrible pizza in the evening. In the morning I had oat so simple and a bottle of water. I hope this was the cause. I haven't been out on the bike since and would hate the same thing to happen again.

The Stiglet

2,063 posts

223 months

Monday 20th February 2012
quotequote all
I too agree with everyone else, seems more like a 'battery drain' and fitness issue as opposed to a proper bonk. Interestingly, I would have said that your food and water intake was sufficient but maybe it wasn't quite enough and this led to you running down.

Personally, I haven't yet needed to get off the bike going up a hill but I came very, very close to chucking it all in near Hythe in 2010. We'd started in central London and cycled our way down to the Coast on a hot summer's day. I hadn't cycled that far before and was unused to the level of food and water required to keep going. I started feeling light-headed, lethargic, grouchy and needed to put more and more weight on the handlebars. Before I knew it I was drifting around on the road, cursing and begging for food, muttering about how much I hated cycling etc.

My girl friend recognised what was happening but was struggling with her own dehydration and we couldn't find a petrol pump station or any shops. We just had to keep bullying on to Hythe and it was on a flat piece of road about 1.5 miles from the centre that my brain just kind of shut down. Couldn't think, couldn't speak, moving around 6 mph until we finally made it to a restaurant. I felt euphoric after eating and almost believed that I'd had some kind of out of body experience, ha ha! Horrible at the time though and pretty dangerous too.

prand

6,244 posts

225 months

Monday 20th February 2012
quotequote all
The Stiglet said:
I too agree with everyone else, seems more like a 'battery drain' and fitness issue as opposed to a proper bonk.
To be honest is exactly what I thought the bonk was! Is it a specifically physiological effect that takes place under specific conditions, rather than just bad prep, under fuelling and over exertion?

Full bonk or not, I would definitely said that the OP was bonking, or on his way to a full on bonk.

Had enough bonks yet?! biggrin

The Stiglet

2,063 posts

223 months

Monday 20th February 2012
quotequote all
prand said:
The Stiglet said:
I too agree with everyone else, seems more like a 'battery drain' and fitness issue as opposed to a proper bonk.
To be honest is exactly what I thought the bonk was! Is it a specifically physiological effect that takes place under specific conditions, rather than just bad prep, under fuelling and over exertion?

Full bonk or not, I would definitely said that the OP was bonking, or on his way to a full on bonk.

Had enough bonks yet?! biggrin
Not quite, there is a physiological change in blood sugar levels that makes you go hyperglycemic. Some of the effects I have already mentioned but this is a good article: http://tunedintocycling.wordpress.com/2008/05/10/c...

XitUp

7,690 posts

233 months

Monday 20th February 2012
quotequote all
As has been said, you didn't bonk, you just got a bit knackered. If you bonk, a minute won't be enough to get over it.

Try taking on calories at least every hour. You were probably dehydrated too, you want 500mls-1ltr an hour, depend on how hot it is/how hard you're going.

nammynake

Original Poster:

2,658 posts

202 months

Monday 20th February 2012
quotequote all
I've done the route before, and found it tiring last time but nothing like this time. I do usually take oaty bars as opposed to mostly sugary snacks so maybe thus played a part. Also I sweat quite heavily even in cold weather - usually within a few miles when I am hardly breathing heavier. Maybe this played a part?

dangerousB

1,701 posts

219 months

Monday 20th February 2012
quotequote all
The other thing to consider is that you may be (unknown to you at the mo') fighting off a cold or infection - that could very well explain why your stamina went south so unexpectedly.

The Stiglet said:
cursing and begging for food, muttering about how much I hated cycling etc.
This is what you want to look out for. Craving food, thinking the terrain's against you and feeling sorry for yourself. Only happened to me once, when I went out for a 140k ride with my bruv out of Club La Santa in Lanzarote after a week long training camp. We'd never cycled more than a 40k TT and presumed naively it'd pretty much be the same, just longer. Set off with a litre of water each and 5 carb bars.

After experiencing eye watering headwinds and gradient for 110k, I started to seriously flag. My bruv wasn't feeling great, but started gapping me at will (and without effort). Coming out of Teguise on the home run (steep downhill), I thought "I'll be fine, just 20k's" - bruv said he'd work the next stint on the flats and to just draft him home. Hit the flats and my legs just died. Every pedal revolution took stupid effort. I had to knock out cogs just to keep moving. My bruv started to sail away and the headwind hit me again. I'd eaten my last bar 30k ago. My stomach was craving food. I reached for my water. It was empty.

I shouted to bruv "any bars left". No. "Got any water". No. That was it. As far as I was concerned the world had just stopped turning. I had to get off. Aside from anything else, it was humiliating. I felt pathetically sorry for myself. You could have taken a photo of me right there and then at the side of the road, with my legs propped up against the Canarian armco and just scribbled an enormous "FAIL" right across it.

The final 20k seemed an eternity. Bruv had his own episode on catching sight of La Santa 5k out (definitely survivors syndrome) and on getting back we literally fell off our bikes, laid in the foetal position for what must have been 10 minutes, then decked 2 portions of chips and 2 pints of coke each, looking like pigs in the process. Then we slept for 4 hours!

It was the most hideous cycling experience of my life. As I'm writing this, I can still remember every single second, the desperation and hopelessness and knowing I was powerless to do anything about it.

I never want it repeated!!

nammynake

Original Poster:

2,658 posts

202 months

Monday 20th February 2012
quotequote all
dangerousB said:
The other thing to consider is that you may be (unknown to you at the mo') fighting off a cold or infection - that could very well explain why your stamina went south so unexpectedly.
Actually I did have a very mild cold - felt like a weird pressure difference in my ears, if that makes any sense?

dangerousB

1,701 posts

219 months

Monday 20th February 2012
quotequote all
nammynake said:
Actually I did have a very mild cold - felt like a weird pressure difference in my ears, if that makes any sense?
Dollars to doughnuts that's it mate . . . that pressure thing sounds like blocked/partially blocked eustachian tube by the sounds of things. Definitely an infection of some sort.

You'd be amazed at the difference even a mild infection can make to your body's performance.

The Stiglet

2,063 posts

223 months

Monday 20th February 2012
quotequote all
dangerousB said:
Dollars to doughnuts that's it mate . . . that pressure thing sounds like blocked/partially blocked eustachian tube by the sounds of things. Definitely an infection of some sort.

You'd be amazed at the difference even a mild infection can make to your body's performance.
teacher What he said, absolutely.