A while back some of you may have noticed a big switch in my race nutrition. I figured I would address why in a blog post because questions about nutrition are probably the single most asked about topic whenever I do a talk about running. There’s a good reason for that since there’s a lot of info about training but not a lot on nutrition for an ultra.  Most people feel they have to good handle on the training side of things but on the nutrition side there isn’t a lot of info.

Nutrition can make or break a race over about 2hrs. Under that and you can mostly get by pretty well on your glycogen stores. Sure a little carbohydrate is going to help but it’s not going to make a huge difference. Over 2hrs however and all of a sudden you can go from running 7min/mi to walking 15min/mi over the course of about 10min. Trust me, I’ve done this many times trying to test this theory.

I’ve had a bonking (when you run out of glycogen, not the other kind of bonking) issue for years. Back in 2011 when I was tested for VO2max we also looked at my “metabolic efficiency” or how much fat I’m burning relative to carbohydrate at a given heart rate. Well, due to my background in high performance (relatively) short distance races I was burning all carbs all the time no matter what HR I was at. After changing a few things in my diet and training, namely started to eat more fat and take an oil supplement Udo’s Oil from Flora Health I went back and checked my metabolic efficiency in 2013. Now I was able to utilize my fat stores more efficiently and I was on the “normal” range of metabolic efficiency.  

So why then, while I had dramatically increased my ability to run longer by drawing out my glycogen stores by utilizing fat at the same time, was I still bonking in races over 50k. I had a theory (obviously this is just my theory and may be debunked in the near future by other more qualified individuals).

In your intestine you have receptors that can process different sugar molecules including receptors for fructose and receptors for glucose. These receptors are specialized, meaning a fructose receptor can’t process glucose.  If you’re only taking in one type of sugar and you’re maxing out those receptors then that’s the maximum rate of carbohydrate absorption. But, if you then add another type of sugar, then those receptors can start processing more carbohydrates, effectively increasing your carbohydrate absorption.  Scientists have figured out that an optimal sugar mix is 2:1 glucose polymers to fructose. It’s important to know what the mix is of the fuel you’re putting in.  While that’s probably a simplified version of what’s happening I was finding that the gel I was taking wasn’t working for me over the longer races. I wasn’t able to take in enough carbohydrates.

Well, by accident during the 2012 UROC race I had been taking Hammer gel for the first 1/3 of the race when I missed my drop bag and was then forced to use the gel at the aid stations. That gel happened to be GU Roctane gel. A 2:1 mix of carbs plus a little caffeine and amino acids. For whatever reason I had the best ultra I’d had to date. Energy levels were steady all day and I was able to push at the end. Something I’d never been able to do before.  I attributed it to the change in nutrition since that was really the only thing I had changed but only after several more races on Hammer gel and experimenting with different other gels and amounts. I’m a slow learner.

In addition to the 2:1 carb blend there are a few other ingredients that set GU apart. The BCAAs (branch chain amino acids) that aid in reducing fatigue over longer efforts and can enhance muscle protein synthesis. And the added histidine that aids in the formation of carnosine to help buffer against changes in pH. So many things that go into a little bit of gel that I didn’t even know could effect performance. Amazing!

Now I’m not saying that Hammer is a sub-par product. I really like Hammer products but something just wasn’t working for me. That’s the thing about nutrition, it’s very individual and you have to find what works for you, and Hammer gel works great for some people.

This will be my first full year on GU and I’m excited to see what it brings. Will I always have a great race from now on, no probably not, although I wouldn’t mind if I did, but I’m hoping the switch will generate faster carbohydrate absorption and I’ll be able to push harder and run longer than I ever have before.  The learning curve in ultras can be substantial and it’s amazing what an important role nutrition plays, both daily and race day, play in a successful race.