paul8f asked in SportsCycling · 9 years ago

Unexpected energy bonk or "the knock", while cycling?

I know what causes "the bonk" or "the knock", but what could cause a rider to hit the wall unexpectedly?

All conditions were the same as usual (weather, distance, pace/effort, terrain, previous meal, hydration etc..)


2 Answers

  • 9 years ago
    Favourite answer


    Prior meals, heat, ride intensity, just the week you are having? All or any could play a part. Over the years, I know that I can ride just fine out to 40 to 60 miles with just my normal dinner, and a light breakfast.

    On hot days at that distance I use water with crystal light. I have Gu in my jersey pocket 'just in case'. A the 60 and above range I know I have to pay more attention to my hydration and energy management. I will carbo load the night before, IO will use an energy drink during the ride. I know I will need to make a stop for both water and some energy replacement. If nothing else I take some snacks... but, I always take some cash for a meal if needed. I also ALWAYS have several Gu gels in my jersey pocket.

    Find out your needs by noticing the differences your body tells you about. Hot vs cold rides, longer vs shorter... with breakfast and without. With energy drink and without. Once you get your arms around the variables, it can help to predict your needs and concenrs!


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  • John M
    Lv 7
    9 years ago

    It could be the way you rode that day or what you ate the day before. Pedaling too hard will use more glycogen then normal or if you didn't an adequate supply to begin with. A good head wind can make a huge difference in the amount of energy you use. Sometimes you just need to take a day or two off.

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