Sunday, March 9, 2008

Caloric needs experiment

I went walking this past weekend. 18 miles, in fact. Most was roads, some was boardwalk with an inch of packed snow.

It was msotly an experiment of caloric intake- I wanted to see how much food my body wanted over the miles. In the morning, I went to a grocery store and bought the following:

3x Generic poptarts, 420 calories per package (two tarts)
4x Snickers, 280 calories per 2.07 oz bar
Nature's valley peanut butter granola bar, box of six; 180 calories per 1.5 oz package (two bars)
32 oz Gatorade, 50 cal/8oz; 200 cal total. (only purchased b/c I needed a water bottle)

I was carrying a lot of food for how long I anticipated traveling. In the end, I ate one package of pop tarts, one snickers and three bars. I drank the gatorade and 1.5L of water. I consumed 1440 calories over 6 hours and 18 miles; that is 80 calories per mile and 240 calories per hour.

I ate the Pop Tart right away; the first granola bar two hours later; the next granola bar an hour after that; the next granola bar an hour after that; an hour later, the snickers, an hour later, third granola bar. At six hours, I was home and hungry, having not eaten in an hour. Had I been camping, I would have been ready to cook supper.

The 80 calories/mile seems in tune with Ryan Jordan's rough estimates of 100-150 calories per mile on trails. I knew I would be on the low end of that spectrum, but I did n't realize (though I should have) that I would be beneath the spectrum. It made sense - I was walking with minimal packweight (2 lbs, maybe), with running shoes and on roads with minimal hills.

So what should I figure for the SHT? Well, I'm going to guess at 125 calories/mile. Some days a hella-hilly (3K+ ft cumulative elevation gain), while some days have a minimal amount of hills (600 ft cumulative elevation gain). THat puts me at 2125 calories/day. That seems low, but I don't want to pack too much food. I've never, ever run out of food on a trip, and I'd like to push my food rations as close to minimal as possible. Once I establish a cushion for safety, then I need to be able to calculate what is a needed amount.

I'll probably pack 2500 calories/day @17 miles per day. That is a difference of 375 calories, about 3 oz of food. I realize that that is potentially two pounds of food extra being carried, but If I eat it and keep from bonking at the end of the day, so be it.

My idea is to have a calorie drip i.e. eat about every hour to two hours, depending on the last food consumption, and not stop for lunch unless necessary. The rests will come in stretch breaks, conveniently timed for when we eat.

The current setup is a package of opo-tarts; two hours later, a granola bar; one hour later, a candy bar; one hour later, "lunch," a calorie dense mixture of chocolate and nuts; two hours later, a granola bar; one hour later, a candy bar; one hour later, we should be at camp and cooking.

This leaves us with two four hour sections of hiking at 2 mph. at 2.5 mph, we're looking at 20 miles.
How far we hike is another questions; this one, appears, tobe settled. Our current time-frame leaves us with about two weeks; I'm planning 13 days - the first day is travel, the second is a three hour drive up to the northern terminus and then a full day; every other day is a full day.

If we do not resupply, the first six days will be 15 miles/day, the last six will be 20 miles/day. If we do resupply, we'll do somewhere in the middle, probably about 17 miles (17x12 = 204, the length of the trail).

Calories will also change with respect to the amount of miles we put in; 20 miles will require ~625 more calories than a 15 mile day would; that is about five ounces of food. We haven't decided what we're going to do yet.
- -
It's all going to get figured out; I think it's really a guess.

With the walk

No comments: