I’ll never forget my (non-cyclist) friends’ face when I first mentioned trying to avoid the “bonk” during a ride. It’s such staple part of cycling vocabulary that it really didn’t occur to me that she’d think I was trying to sell myself as some sort of two-wheeled Casanova.
After re-assuring her that I wasn’t indeed just using road cycling as a very exhausting and expensive alternative to Tinder, she asked me to explain the concept of a “bonk” in cycling.
So, if you ever find yourself faced with the same incredulous expression that I was treated to, feel free to show your gobsmacked friend this blog post instead.
What in the world is a bonk?
A bonk basically means you are hitting the wall, big time. A bit like the wall that long-distance runners hit around the 20-mile mark in a marathon, this is a wall so big that you can find it impossible to carry on. You are spent. Done. Zero left to give.
On a serious note for a minute, a bonk is actually the onset of hypoglycaemia; a condition well known to cyclists and competitors in many other endurance sports.
What is hypoglycaemia?
If you are suffering from hypoglycaemia, it essentially means that you haven’t taken in enough carbohydrates and you’ve exhausted your body’s glycogen stores too. This situation leaves you with extremely low blood glucose levels which in turn means that your body can’t function normally.
What do you need to watch out for?
The symptoms of a bonk are recognisable as the symptoms of extreme exhaustion. You will feel very tired, very physically weak and probably very hungry. This can be accompanied by light-headedness, sweating and shaking, any maybe even palpitations. Riders experiencing a bonk can also exhibit moodiness and irritability due to the lack of glucose.
In extreme cases, if blood glucose levels become too low, it’s possible to fall into a coma.
Treating a bonk
Ever wondering why cyclists, runners and other endurance athletes insist on sucking down those pretty nasty tasting gels like they’re the elixir of life? Well, that’s because they are. Those gels provide an injection of simple carbohydrates that raise your blood sugar levels extremely quickly. If you feel a bonk coming on, an energy gel (or handful of sweets such as jelly babies) will make all the difference in warding it off.
Don’t be tempted to try and see off a bonk with sandwiches, energy bars, crisps etc as these won’t raise your blood sugar levels fast enough and you’ll be heading straight to bonksville. Game over, without passing GO or collecting £200.
If you have managed to catch and treat the bonk early enough (e.g. before symptoms become too serious) there’s no reason you shouldn’t carry on your ride. If you do keep going, make sure you get into a routine of ingesting high carb snacks to make sure your blood glucose levels remain high enough.
If you have been showing more serious symptoms, it’s recommended you dismount, have a rest and give your body chance to recover. Once the symptoms have abated and you’ve taken on some carbs, you can continue again following the advice recommended above (regular ingestion of high carb snacks). You might feel a little foggy though, so be sure to take extra care and be alert to hazards around you on the road.
Dodging the bonk
So how do you defend yourself against the bonk? Well, unsurprisingly, it’s all about the carbs.
Before the ride: make sure your glycogen is fully topped up through carbohydrate loading. Don’t go totally mad on the pasta though, we only need 7-10g of carbohydrate per kg of body weight per day.
During the ride: Replenish your glycogen stores throughout the ride using gels, high carb snacks and carbohydrate sports drinks. DON’T wait until your hungry. Replenish throughout (once every 30 mins works well). Set a schedule and stick to it, even if you need to set an alarm to remind you.
It might seem over the top, or unnecessary at first, but you soon get used to it and will certainly feel the benefit when you’re powering to the top of those cols.
So, why not come and join us in the Alps for a week-long holiday of stunning scenery, breath-taking cols and absolutely no bonking whatsoever.
It’ll be fun, we promise.