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Fat Adapted: Running an Ultra on the Paleo Diet

I went Paleo in March of 2013. My body felt better, younger, more energetic than ever, but my endurance running suffered during the transition to becoming fat adapted.

27 days into the Whole30 Program, I ran a 50 miler but fell prey to terrible leg cramping

Three weeks after, I ran a tough, hilly 20 miler and felt strong all day. Six days later at Capon Valley 50K, I added nut butter, banana and dried apricots to my fueling regimen but ran out of gas and walked it in.

I kept tweaking my nutrition, but I couldn't seem to find a winning combination.
What was different? I'd ingested a bun-less burger during my 20 miler, perhaps protein was the key! 

In my final long-ish, hilly run before my big race, I ate a packet of VFuel (which contains protein). Since the run was a mere 3 hours, there wasn't time to take in much nutrition. Probably not a fair shake, but discouragingly, I sensed the onset of cramps in the final two miles.

Desperate to figure out a way to make my ultrarunning work without sugar, I recalled that Devon Yanko uses Vespa as her fuel. After some research, I decided to use Vespa Junior for my 70 miler. Having failed with my other concoctions, what did I have to lose?

According to the Vespa website, it helps the body utilize fat stores for energy, especially if your daily diet is Paleo/low carb. You still eat some carbohydrate during the run, but much less than you'd otherwise need. It also appealed to me because I could avoid consuming a lot of sugar.

I consumed one Vespa Junior 45 minutes before the race began, then one every three hours during the race. I waited an hour or so after taking the Vespa and then I ate a sweet potato baby food squeeze packet or a few bites of a LARABAR every 15 minutes for carbohydrates. I drank plain water, but in a departure from strict Whole30 protocol I nibbled on Nuun tablets for magnesium, calcium, potassium and sodium. I hoped this would stave off any leg cramps.

This plan worked beautifully for 63 miles, at which point my legs began to feel excruciating pain. So this was what ultrarunners Olga King and Larry King had experienced! I whimpered a bit in the final miles, glad that this was not a 100 miler.

I still count my race at Laurel Highlands 70 Miler as a fueling success. While I was sufficiently trained for the distance, I was certainly pushing the upper limits of my distance range. 

Hopefully, in my next ultra, I'll have the same success. I'll be sure to post about my results. For now, I'm enjoying all that summer has to offer.


  1. So interesting, Kir. Thank you for sharing. I think fueling in ultras is super under-rated, esp. by old-timers like me. I've been experimenting with more fat and fewer carbs recently, and it seems as if I'm a lot stronger later in the weekly 4-hour-plus runs than before. Here's to experimentation! :)

    1. Cool, B! It's good to try new ways and explore new paths.

  2. Hey! I just found your blog through googling the VHTRC women's race coming up. It will be my first trail race and I'm super excited! I have a question for you- in ultras, do most people run the whole time? Or is it a combination of running and brisk walking?

    1. Mackenzie -- that's great! Leave your watch at home and expect heat and humidity, and you will have a blast.

      In most trail races/runs, most of us walk up the big hills. The front of the packers probably run most of the time, but in a mountainous ultra or in 100 milers I'm pretty sure they hike up the big hills as well. Since this is your first trail race, and there are many hills, I'd suggest you walk up all the hills, at least until near the end. If you are feeling strong you can go full throttle then.

      See you there!

  3. I've been wanting to try Vespa for a very long time, but find very variable and controversial reports on it, and it's not a cheap item to just "try". I hope it works for you in longer races!

  4. This is a good summary of all your other posts I've read on the topic so far. I haven't heard of Vespa though, so I'll have to look into that. I feel like I've been doing my Paleo fueling right so far, I just need to experiment around a lot before race day.

  5. Thanks Aubrey. Everyone is "an experiment of one" so that's all you can do, try something and see if it works for you. Best of luck!

  6. I find all of this so interesting. Hubz has gone Paleo and I'm trying to give him some tips, but since I don't follow it, I'm counting on y'all :)


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