How to Avoid Bonking


Nutrition Question: I’m often asked how to avoid “bonking” on long rides, runs, and especially, races.  After all the preparation, no one wants to end up in the fetal position on the side of the trail or road.  Many athletes feel that they have their nutrition dialed in, but still fear the notorious bonk when the going gets tough.  How can you dodge the bullet?

Kelli’s Answer:  Assuming you do have your nutrition dialed in, there’s one situation that almost always ends in bonking.  Among my associates and fellow athletes, my clients, and myself, it can be the kiss of death, especially in a race.

What is it?

It’s the situation of getting behind your expected pace, for reasons within or outside of your control, throwing your nutrition plan out the window in order to catch up, and then finding yourself behind and on empty.  I’ve been there.  I’ve done it (I’m not proud).  But, when you see competitors passing you after a crash, a flat, a blister, mechanical issues, etc, it’s easy to begin to panic.  To go into overdrive and begin neglecting anything that will take up too much time.  Things like stopping at aide stations.  Reaching into your jersey for your bottle or food.  Or refilling your hydration pack.

I am a strong believer in hydrating and fueling to a schedule.  Not to hunger, not to thirst.  I can appreciate the recommendation to drink to thirst and eat to hunger (especially with any risk of overhydrated @ more than 32 oz. per hour and WITHOUT electrolytes).  In perfect race conditions, it might work.  But, in my experience it’s just not practical.  I fuel to a schedule because endurance event throw all kinds of twists, turns, and obstacles at you.  It’s not always possible to drink when you first become thirsty, and in my experience, the time difference between first feeling thirsty, and feeling parched and dehydrated, can be sudden and drastic.  Especially in the heat.  Which brings me to this last weekend’s experience…

I’m happy to say I’ve learned from my experience.  While riding Moab’s wonderful Magnificent 7 trail solo, I found myself behind schedule.  Since I was by myself on trails I’d not been on before, in the middle of the desert, I took my time triple-checking my route.  I also walked lots of drops and rode cautiously, as a broken bike, or a broken leg, would have left me in a lurch.  It was 85-90 deg F. I was expected in town 30 minutes ago, and I knew my husband and kids would start to worry.  I was likely 30 minutes from a cell signal.  Up until now I had been doing fine with fuel, but I had just drank the last sips in my Hydrapak and needed to refill it with a bottle out of my pack.  I fought with myself for several minutes deciding whether to stop and refill or not, all the while my mouth becoming drier and drier.

I stopped.  I refilled.  I drank, felt great, and finished strong.  It may not have been the high intensity 100-mile mountain bike routes I used to race, but it was still a great ride, good fueling, and the right decision.  I encourage you to make this decision as well.  Plan your race (ride, run, etc), and race your plan.  Stick to it, even when panicked about your position…most likely, you’ll be strong enough to get back where you should be.  Or alternatively, you can bonk and find yourself further and further behind.  The kiss of death strikes again!

Please send us your questions for our Expert Sports Nutritionist, Kelli Jennings to “Ask the Sports Nutritionist“. Kelli Jennings is a Registered Dietitian with a passion for healthy eating, wellness, & sports nutrition. For more information go to

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3 Responses to “ How to Avoid Bonking ”

  1. Malachi on June 12, 2012 at 5:08 am

    Kelli, I’m not just a cyclist but as a survey tech I hump 30 to 60 pounds of gear in the woods and hills of Pensylvania. My days can be 8 to 12 hours long and the job needs to be done. I’ve got a crew man who needs to read this! Hope to have up to his first charity ride the tour de cure by August. But if I can’t convince him to manage his fuel/water intake better I’m hoping your article can! Thanks.

    • Darryl is Loving the Bike on June 12, 2012 at 7:30 am

      I hope it helps out your crew man, Malachi. Let us know if you guys have any questions on this at all….we’re here to help.

    • Kelli Jennings, RD on June 14, 2012 at 10:01 am

      Hi Malachi,
      Thanks for your comment! I hope it helps…all the best for you on the job and your crew man on his ride! Let us know how it goes for him…


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Sugar Alternatives for Energy and Hydration

Question: I am using the homebrew sugar formulations (sometimes added to green tea).  I am also trying to wean myself off 1/2 dose adrenalean “lip tonic delivery system” (biorhythm brand- caffeine, hoodia g, synephrine, yohimbe) capsule for energy.

My question is other than juice, can you suggest modifications in lieu of table sugar for energy and hydration.


Both raw/organic honey or agave can work great in the homebrew (substitute in the same quantities for the sugar, or to taste), but you do have to shake well in order to make sure they don’t settle out.  Have you tried either of these?  Also, make sure to use at least the minimum amount of salt recommended in the homebrew as the temps rise, you need the sodium replacement if you’re sweating.

Sports Drink Homebrew

Please send us your questions for our Expert Sports Nutritionist, Kelli Jennings to “Ask the Sports Nutritionist“. Kelli Jennings is a Registered Dietitian with a passion for healthy eating, wellness, & sports nutrition. For more information go to

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