Saturday, March 29, 2014

Provisions for JMT 2014 - part 1

There are four different areas of planning when preparing for a thru-hike. They are Route, Logistics, Provision, and Gear. My focus today is on Provision. Provision in this context means figuring out what you are going to eat and when you are going to eat it. I have previously spent some time and blog space preparing for and documenting my route and logistics. From that planning effort I have determined that I will need to have enough food for thirteen days of hiking. I have further broken-down those days into thirteen breakfasts, thirteen dinners, and twelve lunches. I also determined that I will use two resupply points. One at Mammoth Lakes and the other at Muir Trail Ranch. I will divide my food into three different caches: The food I start with when I begin in Yosemite Valley, the food I pick up at Mammoth Lakes, and the food I pick up at Muir Trail Ranch.

In addition to the food I am eating on the trail, I plan on bringing a fresh, locally-purchased lunch on my first day and secondly, having a locally purchased lunch and dinner in Mammoth Lakes on my 'town-day' when I resupply there.

Here is the break-down of the number of each 'trail' meal that I need for each cache:

Cache Breakfast Lunch Dinner
Start 4 3 4
Mammoth 4 3 3
Muir 5 6 6
Totals 13 12 13

After spending quite a few hours reading and digesting (Ha, that's funny) the information in an article published on the web called Pack Light, Eat Right. I have adjusted my plans so that 'Lunch' begins approximately one hour after I begin hiking and ends approximately one hour before I stop hiking for the day. I have calculated my average hiking time per day to be approximately nine hours per day. According to the article I will need about 25-50 grams of carbohydrates every few hours of hiking to keep up my glycogen levels (whatever glycogen is, it sounds important for sustained energy). The article talks about carbohydrates and fat, which is 'better', etc. I learned that carbohydrates and protein have 4 calories per gram and fat has 9 calories per gram. I also learned that with training you can actually train your muscles to burn fat rather than sugar.
This reminded me of a talk by Covert Bailey I watched on PBS years ago where he said you could become a 'better butter burner' that idea has stuck with me since then and this article seemed to confirm stuff I have believed for decades.

Pack Light, Eat Right provides a list of Trail Snacks...  Oh man, look at all the numbers! This caused me to begin my own research into the numbers on the nutritional labels of my favorite trail snacks. I feel a spreadsheet is in order... I began by putting the serving size, the grams of carbohydrates, fat, and protein on the sheet. I rounded the 25-50 grams every few hours to 20 grams per hour as a target for planning. I was a little confused by the article's proposition about eating 25-50 grams of carbs and how to translate that into 'high-fat' snacks for muscles trained to burn fat. I just made some assumptions based on nothing but the idea that 25 grams of carbs X 4 calories per gram = 100 calories. I then created another target of 100 calories per hour. I averaged the two targets and got a percentage that I used against the serving size on the label. I multiplied that percentage against the serving size and got the number of grams of each snack that should be eaten per hour. Once I converted the grams to ounces I was surprised to find that a rough guideline is to simply plan on eating 1 ounce of a snack per hour while hiking. Then using my previous numbers of 12 days X 8 hours (average) per day = 96 hours = 96 ounces of snacks.
My analysis of my favorite snacks

The high-fat snacks have about half the carbohydrates suggested by the article but have more than twice the calories. Then I selected the number of servings that I want of each, trying to balance the number of high-fat snacks with the low fat ones. The green boxes are my targets for the snack types. The spreadsheet shows my preferences and also calculates that the resulting weight of my 'lunches' is 6 lbs  7oz.

All of these numbers and calculations are rough approximations and simplify the process of determining what and how much food to bring. I still need to finish my breakfasts and dinners; I think they will be easier to determine but I'll leave that for a different post.


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