As I continue to look carefully at my own race day diet, I don’t
like what I see. Gels and energy drinks are full of sugar and sugar tends to make me sick.
As previously mentioned on here, my metabolic efficiency test
a few weeks ago revealed that I need between 62-187 calories and between 9-27
grams of carbohydrate an hour in a 100-mile race. Over the weekend, I started
reading labels of products I used at this year’s Leadville 100—and boy was it
painful. It was one of those “I wish I could go back in time and do things
differently” moments.
Let’s start with Carbo-Pro, a source of calories I’ve used
in multiple Leadvilles (all of which featured puke fests, but nothing quite like this year). A serving of Carbo-Pro,
which I used from miles 24-50 this year, has 200 calories and a whopping 50
grams of carbs. Most of those calories come from pretty much pure sugar. So,
when you look at Carb-Pro and my test results, can you see that a serving has a
few too many calories for my needs—and almost double the carb grams per hour I
can handle. Plus, I wasn’t taking Carbo-Pro by itself; I was also taking it
with VFuel gels. That means, per hour, I was taking in about 300 calories and
almost 80 grams of carbs.
It’s no wonder by mile 50 I was doubled over vomiting. I had
put in my stomach way more than it could handle, and the vomiting was its way
of saying, “enough, please.”
We are told that 100-milers are eating contests with some
running mixed in. The more you can eat, the better, it’s said. But as I’m coming to learn, it’s not a game of jamming as many
calories in your body as possible. Success comes down to giving your body what
it needs, and what you need and what I need can be two totally different things.
After reading those labels, it started to make sense to me
why in training runs over the summer my gut stayed happy but at Leadville it
went south. The reason was that in training runs I tended to stay within my
limits as far as calories and carbs per hour. I would take a VFuel gel about
every 90 minutes or so, usually not starting until the second hour, and all
would go well. Yet at Leadville this year I told myself that I needed up to 300
calories an hour, so I forced stuff down my throat that my stomach ultimately
couldn’t handle.
The key, I believe, is finding out your nutritional ranges
and staying within those ranges. Admittedly, I'm still trying to figure myself out. But at least now I have some data to use.
However, it is a bit more complicated than just eating less. The real issue is that the data you have laid out above paint an impossible picture. You are burning nearly 60% carbs at a 103 HR. That means at heart rate that more or less represents walking (in effort) you are burning 360 kcals from carbs. If you eat your top end range -- believed to be 187 kcals per hour of carbs (regardless of source) -- then you are running a 180 kcal per hour deficit, roughly. Assuming you can burn something close to 2000 kcals of glycogen before bonking, that gives you 11 hours before you hit the wall. This is all somewhat theoretical -- though grounded in science and research -- but it illustrates the point. How do you narrow that 180 Kcal per hour gap down to something more like 100? If you get to 100 Kcals an hour deficit, then you could go 20 hours before hitting the wall. If you aren't willing to fat adapt through training and diet, then your only choice is to try and eat 300 Kcals per hour and hope like hell your stomach can take it.
ReplyDeleteMaking the picture even more grim is that very few people actually stay at such a ridiculously low HR for much of the first half of the race. I guarantee virtually no one matches that effort level for the 5-8 hour journey back and forth over Hope Pass, which means that 180 kcal deficit is growing much larger. If you are burning 60% carbs at an effort level that resembles walking, you are likely burning close to 90 or 100% carbs going up and over Hope Pass. It makes sense that most people find themselves in an impossibly big hole at Twin Lakes and have huge positive splits in the race.
The challenge is burning a higher percentage of fat so that kcal deficit from carbs stays at a reasonable level, including heart rate ranges higher than a 100 mile effort. Once that is accomplished, then the question becomes what sources of carbs do you use to replenish (sugar, starch, etc...)
Thanks for sharing this post. And congrats for completing Leadville this year - this is an amazing feat and a stellar finishing time. From what I can gather, this may be a good time to start exploring other products as this year winds down and you prepare for any major races for 2015.
ReplyDeleteI've recently started using Generation UCAN for longer runs. With no added sugar, the company believes the product will serve as a gel replacement and lower the likelihood of sugar spikes and crashes. Though I'm not preparing for a race as nearly as lengthy as Leadville, I've been using UCAN for fall marathon preparation. Thus far it's working well. I'll be curious to see how you keep exploring the nutrition component of distance running.