If you’ve been to a running store or sports outfitters lately, you may have noticed the growing shelves of neon colored packages of supplements that are supposed to be consumed for energy during exercise. There are now umpteen brands of powders, goos, bars and candies; wafers and cookies; pre-, post- and during-run drinks.
So it’s no surprise that one of the most common questions I get from runners these days is whether and when to consume these. To answer that, a quick bit of background on how our body uses fuel to create energy:
During exercise, we use stored fat and carbohydrate as fuel. While we have hours and hours of fat to burn for fuel, it's not quickly accessible. However, the stored carbohydrate in our muscles (called glycogen) is immediately available for energy. The catch is that we only have 60-90 minutes of this rocket fuel stored in our muscles and ready to go. If you begin running an endurance event at too fast of a pace or if you don't adequately carb load for an event, you may burn through that glycogen long before you've picked up your medal. So you would just tap into fat then, right? Not so fast. Running out of glycogen with miles to go before the finish line can spell disaster for a runner. Not only do your muscles use glycogen, your brain and other systems do, too. (Check out a post I wrote in the spring about my truly epic bonk.)
This brings us back to the question of whether and when to use supplemental nutrition on a run:
In a 5K or 10K race or in a run under 75 minutes, unless you're diabetic or hypoglycemic, there's no benefit to supplementing with carbohydrates (or to carb load the night before if anyone's asking).
However, during an endurance event of two hours or longer, consuming supplemental carbohydrate will help to keep you adequately fueled and running strong. If you plan to supplement during your race, you'll need to practice using those gels, chews or drinks—or even with real whole foods—on your long training runs.
(Note that a number of the products showing up on the shelves of running stores don’t actually contain carbohydrate for energy. Some are formulated to support hydration and contain very few carbohydrates or calories, so read those labels or ask for help.)
Just how much carbohydrate your body requires on a long run depends on your size: A runner needs anywhere from 25-60 grams of carbohydrate per hour, which is a pretty huge range. You can find calculators on the interwebs to estimate the range recommended for your size, but the proof of the pudding (or gel) is in the tasting: Use your training runs as your science lab and find out what products work best for you (and which ones don't!) and in what amounts. Remember that you don’t have to supplement every long run with these fuels. Toughing out some runs without that added fuel can teach your body to be more effective at using fat for fuel.
Now go have fun out there!
Not sure how to apply this information to your own run? Let’s talk! firstname.lastname@example.org