To bonk, or not to bonk

Ryan Correy February 21, 2016 No Comments

By Athlete Ambassador, Rene Unser of PACE Sport Fitness

It was during a hot August day at the Squamish 50k ultra when I underestimated what I had left in my pack and blew through the last aid station.  10 minutes later I found myself leaning up against a tree, begging every passing runner for a gel. Excuse me, do you a spare gel?  Nope. People whizzed past me. Sorry to have to ask, but could you please spare me a gel? Nope.  These people were all smarter than me and checked their pockets heading into that last aid station. Gel?  Anyone?  ANYONE?  I lost track of how much time passed before a runner finally came by with an extra to spare. I perked up, mustered the energy to smile and anxiously held out my hand. As he reached into his pack and pulled out the gel, I couldn’t believe my eyes.  I politely accepted it, scarfed it down and then started walking.


On Day 8 of the Gore-Tex Transalpine Run, I placed my hand on my buddy’s butt and pushed him up the trail.  We were in the Italian Dolomite Mountains, surrounded by beauty and only one last massive climb stood in our way of finishing the race. My buddy picked up a bug the day earlier and was hitting the wall so hard he could barely walk.

Being on the other side of the “bonk” is no joke either and it’s often hard to know how to help. I was getting exhausted and wasn’t sure how much longer I could push him, so I made him pull over and forced him to take a gel, despite knowing he had a hard time stomaching anything at that point.  We were out of options and I remember giving him a pep talk, opening up the gel and forcing him to take it.  Every time he swallowed, his back would arch and he would get close to hurling only to hear me say “keep your damn mouth shut and swallow!” As unpleasant as that moment was (more for him than me), we got through it and both finished.


Hitting the wall, sh#tting the bed, bonking – call it what you like.  It’s basically an overwhelming feeling of fatigue or running out of energy when the body’s store of glycogen, which produces the energy required to maintain performance, is depleted. When the glycogen depletes entirely, it results in a surge of fatigue and a performance collapse.


Before you skip to the section on preventing it, learning how to recognize it is the first step in prevention.  Here are a few sure tell signs you’re going down:

  1. The feeling of severe weakness, fatigue and confusion.
  2. You will likely feel slow, heavy and weak.
  3. If you try to keep going, you may experience shaking, sweating and/or lack of coordination.
  4. Dizziness, light-headedness, tunnel-vision and disorientation are all common experiences.


  1. As soon as you start to notice any of these symptoms, stop and eat some simple carbohydrates that will be quickly absorbed, like one of the tasty Hammer Gels, washed down with plenty of water to help get it into your bloodstream quickly.
  2. If you don’t have a gel on hand, aim for other sugary options like candy.
  3. If you catch the bonk early enough, you might be able to keep running (slowly) and refuel with glucose and carbs.  Otherwise, you should stop, eat and recover before continuing.
  4. It’s not uncommon for people to not think clearly when they are bonking.  Asking for help or receiving help may be an important factor in getting you back on your feet and continuing.
  5. Try to stay positive.  Don’t dwell on it.  Identify, treat and carry on.  Time is sometimes all you need to dig yourself out of a dark hole.


  1. Ensure that your glucose stores are well stocked before you train or race.
  2. If you exercise intensely for more than two hours, try to eat something small every 15-30 minutes. I train with Hammer’s Perpetuem & gels on my long runs. Experiment during your training to find out what works best for you before competitions and then stick with your plan.
  3. Assess the conditions and plan for it.  For example, be sure you have adequate hydration & electrolytes (such as Hammer Nutrition HEED or Endurolytes) in warmer conditions.
  4. If you start out feeling heavy or like you’re already in a deficit, don’t wait 30min to eat.  Have a gel at the start of your run and run or hike at a low intensity for 15-20min to see if your energy improves.
  5. Learn the signs so you can take action sooner than later.  Just remember that the signs can be different for everyone.  Some people may experience heavy legs right away, while others may feel more irritability, frustration or inability to make a decision.

Ryan Correy

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