It doesn’t and shouldn’t happen too often but when it does Hitting the Wall, The Hunger Knock or the Bonk is an experience you won’t forget in a hurry.
On one of our recent club runs we were joined by a new member. Near the end of the run he began to drift back. He stopped and fired a large handful of Haribos into his mouth, he mentioned having a narrowing vision…he’d got the bonk. Thankfully we were only a few miles from Dumfries. This powerful phenomena will visit all cyclists at some point in their cycling. I like to see it as a mysterious process but there is a scientific explanation well summarised in this extract from BikeRadar’s excellent article on the subject.
‘The simple explanation for its occurrence is that long-endurance exercise depletes the body’s store of glycogen, which produces the energy required to maintain performance. When the glycogen depletes entirely, the body has no more fuel and instead burns fat, resulting in a surge of fatigue and a performance collapse.’
That’s it explained in a rather large nutshell. Or is it? The article becomes more intriguing later on when it states that research suggests the bonk...’may be more complex with genetics, mental factors and training all playing a role.’
Mmmm well…That’s the science aspect but what is it like for a cyclist on the road. I’ve had the hunger knock or bonk, several times which I think is about average in many years of cycling. If you’re suffering from it regularly you should perhaps stop your subscription to Eating Disorders Monthly. Cyclists will be able to tell you quite vividly about those memorable moments of physical implosion. They don’t occur too often and you won’t forget them.
I remember on one club run in Spring hooking up with another cyclist and getting up the road from the other guys. My fellow escapee said ‘Looks like it’s just you and me.’ These little contests happen all the time in club cycling. I was game but didn’t really do my calculations. There was still about 30 miles of the route to go, we were drilling it and I’d had a bowl of cereal and a slice of toast for breakfast. As you can imagine this was not going to end happily for me.
We got onto the Solway coast road with its amazing undulations of sea and sky. We took turn about but with 15 miles left, my turns became shorter, less purposeful. I tried to mask my drop off in effort but I eventually had to come clean and say I couldn’t pull at the front. My companion said what all cyclists would ‘Sit in for a while.’ After all he’d calculated I might feel better in a bit and then take my turns again. There’s an interesting observation…no two cyclists get the knock at the same time.
Sitting in didn’t help. My body had abdicated. I started to focus on his cog whirring hypnotically. It became less of a cog and more a blur then a distant worm hole. Nausea rose and subsided. My head seemed empty of any relevant thought or feeling except the sight of the blurry cog. We reached New Abbey, a fit rider and a shell of a human being.
With Whinny Hill coming up I knew I was smashed and so did my fellow roadie. He ploughed on and pretty soon the others arrived. One look at my face and they rode through me. Thank god. I didn’t care. If Stephen Hawking passed me on a motobility scooter making suggestive remarks about my wife I wouldn’t have cared. When you get the knock your universe shrinks to nothing and become a single cell organism. 3 miles to home feels like 300. A rise in the road is like the Galibier. It’s like someone had chiselled out your insides. A disembowelled Zombie could out ride you.
There have been one or two other occasions with The Knock and the process is the same; the miscalculation with fuel, riding hard and the consequences. Funnily enough a couple of years ago, we were out in a large group and my fellow rider mentioned above blew. He told us to leave him. I didn’t feel any superiority. None of us did, only sympathy. We left him to his fate like a rabid dog. The following week he was back in top form. To blow is part of your rites of passage into the cycling world.
Of course there are lots of other ways to feel bad on a bike which do not involve getting the knock. Many riders can be heard talking about a dodgy stomach. Digestion and stomach problems can be a common problem on the road. If you pass wind you better hope it’s just air that follows.
Earlier this winter we rode on wet showery roads past a newly dead badger (they can grow to the size of small bears in the South West). The following week the digestive system went into overdrive. Speaking to the boys, I found quite a few had the same problem. I convinced myself road spray had contaminated my bottle from that deceased Badger. Far fetched? That badger was probably on the grassy knoll when Kennedy was assassinated.
As I said earlier a lot of time cycling is a calculation between effort and fuel. I hope that the more I’ve cycled the better I’ve become at this equation.