Before I got serious about distance running, I viewed fueling on the run as frivolous - what was the point of replacing the calories you were working so hard to burn? That outlook was fine when I was playing with runs of 3-5 miles, but as I started doubling - then tripling - that mileage on a regular basis, my body quickly let me know that it would not happily run on empty for hours on end.
Now with 5 ultramarathons under my belt, I’ve had plenty of time to test and fine-tune training habits and calorie replacement while on the run. My findings are a combination of research, trial and error (hello, low blood sugar bonk), and happy accident (I discovered Uncrustables at a 50K aid station, and now I won’t run without them).
I’ve found that fueling is one of the more personal decisions a runner makes - over time, you will develop your own tried-and-true system - there’s no right or wrong way. (A frequent runner of 100-mile races found my reliance on PB&J sandwiches ridiculous, but hey - they work for me, every time).
Though this is my go-to plan, variables like terrain and weather require flexibility. For example, a day with 1,000+ feet of hill climbs will demand significantly more calorie replacement than a flat run, which is why I’ve included separate plans for trail and road running. Extremely hot weather requires greater electrolyte replacement than a day with mild temps. And almost always, running on a trail leaves me in greater need of replenishment than running on the road. So, without further ado, this is a general look at how I fuel on the run.
Uncrustables are my go-to. Store in the freezer, and remove before a long run. They are individually packaged, small enough to stow in a hydration pack pocket, and thaw quickly.
A note on Gu:
People have a love/hate relationship with the stuff, and I get it. The “Chocolate Outrage” Gu works consistently for me, so I use it, however there are many other flavors and brands to consider. I’d recommend buying a few different options at your running store, and testing on your training runs. Or, forego gel packs completely and reach for something more natural - like fruit, honey, candy - just make sure your calories are covered!
What about water?
Yes, hydration is arguably the most important aspect of fueling on the run, and something I’ll address in detail at a later time. Long story short - respect your body’s need for water, and don’t be caught without it on a run of any length!