I will never forget my first 100km bicycle ride. I bonked so HARD! The same thing happened during my first 200km ride. Needless to say, I have learnt the hard way that bonking is not fun. Bonking in cycling is a very common phenomenon that I think every cyclist has experienced. Bonking is not something unique to the sport of cycling. In long distance running, bonking is referred to as “hitting the wall. I am going to talk more about bonking in this post. I will also go through some of the fueling strategies you can use to conquer every long ride from here on out!
What is BONKING?
Bonking is the depletion of muscle glycogen. When your muscle glycogen stores are low, muscle cells cannot produce ATP rapidly enough to maintain exercise intensity. That is why when you bonk while cycling it is impossible to continue riding at a high power output. It literally turns world tour professionals into cat 5 mammils or worse. A common sign that a cyclist is bonking is that the cyclist will look down while riding and his or her head will begin to bob from side to side. The body posture of the cyclist will also change. The cyclist will be shrugged over the handlebars. A perfect example of this is Mathieu van der Poel at the 2019 Road World Championship. It was a good reminder that even the best cyclists in the world can make a fueling error and suffer from the bonk. Another example is Lance Armstrong during a stage of the 2000 Tour de France. As we now know, Lance was juiced to the gills on every type of performance enhancing substance imaginable. Even with all the drugs in his system, the power disappeared from his legs because he did not fuel properly and… BONKED. There are too many examples to cite, but I think you get the point that when you bonk you are a shell of your former self. This is true for all cyclist, from weekend warriors to world tour professionals.
How to avoid bonking while cycling:
Since bonking is the depletion of muscle glycogen, the only way to avoid bonking is to eat a sufficient amount of carbohydrates.
Before your ride:
The focus of your pre-ride meal should be carbohydrates. My favorite pre-ride meal is a fruit smoothie with added sugar. If I do not have ripe fruit, then I would have a big bowl of oats (also with sugar!) How much I eat depends on how far I need to ride, but I usually eat as much as I can. If I am doing an ultra endurance ride I would eat so much food that I am uncomfortably full when starting the ride.
During your ride:
A great formula to go by is to eat 1g of carbohydrates per kilogram of bodyweight every single hour while exercising. So if you are 70kg, that would be 70g of carbs per hour. You can eat slightly more or less than this, but I would usually recommend more. During a BIG ride, I will eat around 80-120g of carbohydrates every hour, even though I only weigh around 75kg. It is also important to eat before you get hungry. There is a saying in cycling, if you have waited till you are hungry to eat you have waited too long. The biggest fueling mistake cyclist make is that they do not eat anything during the first 2-3 hours of a long ride. By the time they do start eating, it is too late and they bonk. Eating when you are not hungry is an extremely important skill cyclist need to master. Another mistake cyclist make is that they stop worrying about food during the final part of their ride. I will be honest and say that I have made this mistake more times than I can count! What I would do is I would see that I have eaten enough to make it to the end of the ride without bonking and I would stop eating. This would cause me to get home feeling hungry. I might not have bonked during the ride, but what I did do is significantly slowed down my recovery. I now follow the 1g of carbs per kg of bodyweight rule for the entire duration of the ride.
After your ride:
Once again the focus here is on carbohydrates. You are not going to bonk after your ride, but the sooner after your workout you can eat, the better. It will make sure that you recover as fast as possible. Another cycling saying is, the food you eat today is the work you do tomorrow. I like to have another high carbohydrate meal, such as a smoothie directly after my ride. It can be tempting to neglect your nutrition after your ride. The only acceptable excuse to not eating directly after a ride is if it was raining during your ride and you come home freezing cold. In that case, a warm shower will keep you from getting sick and is more important than a meal. Just make sure you eat during the 30 minute window after your ride. If you did not come home starving then eating within 30 minutes after a ride will be more than sufficient.
What about fat and protein?
Fat and and protein have a place in a healthy diet, but in terms of cycling performance the focus should always be on carbohydrates. Nobody, I repeat NOBODY, gets dropped because they ran out of fat or protein during a ride. It just does not happen. Increase your carbohydrates intake, while decreasing your fat and protein and watch what happens to your cycling performance. You will be amazed at the results. You will also understand why pro cyclist eat gels and sugary drinks during a race. I remember catching a bottle from a rider while watching the Tour de France go up the Col de la Colombier in 2018. The bottle was half full so I had a sip. It was so SWEET!
What foods should I eat to avoid bonking?
Here are a few examples of my favorite foods to eat during a ride:
- Sugary drinks (SIS, Powerade, soft drinks etc)
- Energy gels
- Rice cakes
- Sweets (jelly babies, soft gums etc)
You can make your own energy drink by mixing 100g of coconut sugar with 750ml of water! This is a cheap and tasty alternative to any of the energy drinks on the market and it gets the job done. You can technically use any sugar, but I love the taste of coconut sugar mixed in water. 100g of sugar per 750ml bottle of water is a good ratio to go by. You also do not want to make it so sweet that it is hard to drink. If it is too sweet for you then go with 80g of sugar per bottle and if it is not sweet enough then go with 120g.
How much water should I drink during a ride?
This is a much easier question to answer, compared to how much (and what) food you should eat. Just make sure that you are drinking enough water that you are peeing clear every 2-3 hours. How much water you need will vary based on how hot it is outside, how much food you are eating and how hard you are riding. The urine test is pretty accurate, unless of course you are drinking Vitamin C tablets then it might be slightly hard to tell! I usually ride with one sugar-mix bottle on my bike and one water bottle, so when I take a sip from the sugar bottle I also take a sip from the water bottle afterwards.
Everyone bonks at one time or another. It is easy to learn what you need to eat and how much, but doing so is another story. Sometimes you will get carried away in the moment and forget to eat. It happens! It rarely happens to me during training now, but I fell victim to the bonk in a cycling race recently. The race was very hard and I was trying not to get dropped. It was also cold, which meant that I needed to eat more than usual. When it is cold your body uses more energy to warm itself up. Before I knew it, the power disappeared from my legs and I got dropped. Ironically I was riding so hard to try and not get dropped that I did not eat enough and THAT was the reason I got dropped.
So while you will not be immune to “the bonk” after reading this article, at least now that you have the theoretical knowledge on the topic it will make bonking a lot easier to prevent!