© Marcel Hilger © Marcel Hilger

7 tips for preventing a dip in energy while cycling


Dizziness, nausea, fatigue – those are the symptoms that athletes complain of when they experience a dip in energy. Find out how to avoid “hitting the wall”!

Dips in energy: How to avoid “hitting the wall”

Full of motivation, you start your intense training on the bike – but what’s happening now? From one moment to the next, you’re wiped. You’re dizzy, your legs feel heavy and you’re overcome with waves of nausea and sweating. All of a sudden and without warning, it’s here: the dreaded dip in energy, sometimes called a “bonk”. Pro athletes are usually all too familiar with this phenomenon. It comes on abruptly and is followed by a sharp decline in performance. But what causes a “bonk” and what can you do to prevent it? 

Simplon shares their best tips and tricks to help make sure you can always perform your best when competing in a race.

What causes a dip in energy? 

With their daily meals, athletes supply their bodies with carbohydrates. These are then converted into glycogen and stored in the muscle cells and the liver. Glycogen serves as the primary “fuel” that’s being burned during exercise. 

During normal exertion, stored glycogen usually suffices for a day. If exertion increases, stores can run low after about 90 minutes already. 

In this case, muscle cells are forced to rely on fats and blood glucose for their energy supply. This creates a significantly higher strain on the system. The result: a sudden dip in performance due to a drop in blood sugar levels. The central nervous system gets overtaxed, dizziness, brain fog, shaking, sweating and poor concentration set in. The symptoms can happen individually or at the same time. 

You might as well forget about your performance if that happens. That’s why we’ll share what you can do to avoid the dreaded “bonk”! 

Tip 1: Carbohydrates are crucial 

As a rule of thumb: The body needs about 60 grams of carbohydrates per hour of training. Depending on the duration of your training or competition, you should have a meal that sufficiently fills your carbohydrate stores. 

Additionally: You should keep in mind that the more intense the exertion, the higher the ratio of carbs to be used as a source of energy. 

Tip 2: Avoid experiments! 

If you’ve got an important competition coming up, you shouldn’t start experimenting. That means: You might want to reach for foods that you’ve tested while training and that you know provide optimum energy supply. The same goes for the amount. 

Tip 3: Controlled and steady energy supply ahead of the race 

  • 24 hours ahead of the race: The motto is: Eat regularly and keep the carb ratio high in your meals! 
  • 3 hours before the start: Ripe bananas, power bars and energy bars (with low fat content) as well as puffed rice and toast: High-carb foods are allowed and favoured! 
  • 60 minutes before the start: A last carbohydrate boost, for instance, in the form of a ripe banana helps you start the race with plenty of energy.  

Tip 4: Stay away from sweet and fatty foods! 

Chocolate bars, cakes, chips & greasy wraps – don’t fall prey to these temptations that provide quick energy but aren’t appropriate for longer races. The reason: Sweet and fatty snacks sit heavily in your stomach. Especially, if there isn’t enough time before the race for them to be properly digested.

Tip 5: During the race: Supply your body with energy! 

During a competition, the body craves nutrition in the form of solid food or liquids. To keep your glycogen stores full, you should consume plenty of carbs while racing. Gels, bars and carbohydrate-rich drinks ensure you won’t fall victim to the dreaded “bonk”. 

Good to know: There are about 100 to 150 calories in a serving of power gel. That’s up to 30 grams of carbohydrates. If you consume these fast-acting carbs in small amounts throughout the race, you give your body the necessary power to keep going. 

Tip 6: Watch out for hunger pangs! 

Some athletes might be familiar with them: hunger pangs that set in when carb emptying happens too quickly, and the body craves energy due to low blood sugar levels. 

But be careful! If you raid the fridge and thus consume more calories than you’ve burned during exercise, you risk negative effects on your weight and health. Hence, the goal is: preventing hunger pangs from happening in the first place. 

Tip 7: After the race: Recharge your batteries! 

After a competition, regeneration takes priority. Ideally, you refuel your system within the first 30 minutes after exertion with liquid nutrition. Why? A high-quality sports drink is well tolerated, rehydrates you and the important nutrients in it are easily absorbed by the body. 

Important: Alongside carbohydrates to refill your energy stores, the drink should also contain sodium and protein. 

About 1 hour to 1.5 hours after exertion, you can go ahead and have your first solid meal. Keep in mind that it should have a balanced ratio of carbs, protein and fat! 


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