The other day, I went out for a run that wasn’t particularly long or hard, but I started tired, having had a busy and somewhat stressful workday the day prior. Plus, it was the warmest day of the season so far. By mile 5, I was hitting a wall. I felt like my legs couldn’t carry me any further. But 5 miles isn’t normally pushing me to my edge; What gives? Luckily, I knew enough about what was happening physiologically to know that I was bonking. I wrapped up my run as soon as I could and went straight home, reaching for a cherry cobbler in the fridge and topping it with Greek yogurt. I needed carbohydrates (and protein), fast.
The trails are more available than ever and many of us have more time than before, or maybe we just need the distraction, so we are pushing our mileage further and further. But what can you do to prevent running into Bonk City?
First, let’s define bonking.
When we exercise, our bodies have three major ways of providing energy to our muscles. The first two are depleted almost immediately and really only help with sprints or a quick exertion such as weightlifting. The third requires a pretty constant stream of glycogen to the muscles that comes from about a 1500 calorie storage bank in the liver. When we run out of that glycogen store, we hit a wall and our muscles are no longer able to continue. This often leaves us struggling to continue, cognitively “out of it” and more often than not, nauseated. If our body is out of glycogen for too long, it will turn to muscle protein to convert to glycogen, effectively undoing your training.
As a funny aside, when I was at PowerBar, we used to have the slogan “don’t bonk”; you may recall the campaign. At the time, we were just spreading into the international market and had reached Australia, where bonking is something very intimate that you do with your partner. We had some very confused Australians followed by a quick shift in advertisement for that part of the world!
Three Steps to Avoid Bonk City.
1. Never Run Fasted.
If you prefer to run first thing in the morning, make sure you consume something to boost your blood sugar. Even if you eat an energy bar or piece of toast as you head out the door, having something in you will help fuel your run.
You have probably heard somewhere along the line that running fasted helps burn fat stores, but as endurance athletes, you are tapping into your fat stores nearly immediately, especially if you run over an hour. Plus, you can’t burn that fat if you don’t have carbohydrates to help fuel the fire. Make sure you feed the fat burning fire with carbohydrates before, and during, your run.
2. Carry Fuel on your Run.
Even if you don’t think you will need it, it is always good to stash a gel, blocks, or other fuel in your pockets or vest. Sometimes we hit the wall when we least expect it, just like I did the other day. Plus, the weather, what we ate the night before, how stressed we are feeling, or how rested we are all plays a large role in the speed at which the muscle glycogen is used. That 10 mile loop you always do without carrying anything may knock you down at mile 6 following a particularly stressful evening meeting the night before.
If you arrive to Bonk City in the middle of the run, you can often quickly pass through as a mere tourist with a short rest and replenishment of calories (aim for 150 calories of simple sugars – a gel, a bar, or a few blocks is perfect). If you continue to push your body once arriving to Bonk City, it will likely be a several hour stay, even after you finish the run. Your body will be so depleted that the recovery fueling will be imperative.
3. Make Sure You Refuel After.
If you are regularly running, it is really important that you are recovering from your runs with proper fueling. If you don’t fuel well after, you are setting yourself up for a glycogen deficit for your next run, leading to Bonk City much faster. Make sure you are getting a refueling snack or meal within 30 minutes of exercise that contains at least 30 grams of carbohydrates as well as 15g protein. This will replenish your glycogen stores, as well as ensure your muscles are not breaking down.
Would you like to refine your fueling? I specialize in fueling between the athletic moments, but can also help you refine your training and (hopefully someday soon!) racing fuel. Send me a note at email@example.com, I would love to hear your bonking stories.