Does training your body to run long distances without solid food burn more fat? Curious and skeptical, Jennifer puts this fueling strategy into practice.
By Jennifer Pinarski
Updated Mar 29, 2017
Photo by akunamatata via Flickr.
As I aim for longer distances in my trail running and racing, I’ve been reading about how to fuel properly during my weekly long runs.
My usual strategy is to have a high carbohydrate breakfast (usually oats and maple syrup) and to have an energy gel 90 minutes into my run and every 45 to 60 minutes after that.
When I was running 35 kilometres during my Tread 6-Hour Race training, I’d add solid food as well — usually a homemade energy bar containing dates, nuts and chia seeds. None of my fuelling was research-based, just gut feelings — literally. When I’d feel lightheaded I’d eat a gel, when my stomach would rumble, I’d eat solid food. The few times I’d go longer than usual between eating or taking in gels my stomach would punish me with cramps and gas (burps so loud that there is no way a bear would come near me on the trails). And of course, after I’d eaten, all would be well and I could finish out my run.
This brings me back to researching new ways to eat during running and, surprisingly, one of the ways to fuel is to not fuel at all. That’s right — delay taking in food until you bonk and then keep on going.
The no gels while running theory states that, by approaching your long runs this way, you train your body to burn fat, not sugar (gels and chews are loaded with delicious sugary carbohydrates to keep your muscles and brain going). It sounds great — I mean, who doesn’t want to burn more fat? I’ve been wanting to ditch my gels and chews in favour of a less processed fuel source, so what better way to do it than not use gels at all? I decided to give this strategy a try on my long run on Saturday afternoon. I had a planned 20K and, other than a bowl of oatmeal and a few grapes, I had no food in my stomach when I set out six hours later.
The first hour was lovely — I explored my favourite trail and stayed cool despite the heat. My stomach was getting grumbly and I thought I’d just keep running through the noise, choosing instead to have water. It seemed like a good idea, but then I was hit with terrible stomach pains and, yes, burping. I had a backup gel with me, but I really wanted to follow through on not eating.
A few minutes later, water was still sloshing in my stomach and I could no longer run. Several kilometres from home and still in the woods, I stubbornly kept alternating between a fast hike and a hunched over run. It wasn’t pretty. When I finally got home (only 10K into the 20K I wanted), I was in too much pain to head back out for another lap. And so ended my experiment — I can't run on empty an empty stomach. Despite the number of fat reserves I have, I need a constant stream of carbohydrates to run distances for more than 90 minutes.
Have you tried running on an empty stomach? Has it been successful for you?