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paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: the AT in the spring on 11/17/2006 10:46:27 MST Print View

>>"that smell, it's...thru-hikers"

Good one!!!

But, really, that's only in the shelters (which i avoid like the plague).

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: thru hike min resupply on 11/17/2006 13:52:25 MST Print View

Ron-I used a “back of the envelope” model for the Artic 1000 backpacking forecast. I posted my 643 mile estimate to this forum prior to the attempt; the actual result was 620 miles. Of course I realize that my small 3.6% forecast error, in a large part, was just dumb luck <grin>.

There are many different backpacking models that could be applied to analyzing this problem. I think the different forecasts will result in a spirited debate and most importantly a strong catalyst to actually have people attempt the effort to determine which model is right, if any.

The models also have the benefit of allowing us to do theoretical “what-if” scenarios to see how the output of the model changes and compare those results to real world experiences. For example what impact would it have: if hiking boots x were worn rather than running shoes Y; if a fly rather than a tent were used; if garment list X versus garment list Y were used; if sleeping pad X versus sleeping pad Y; or a titanium trowel was carried rather than a plastic one?

For the models to yield comparable results we first need to agree on the input parameters. I suggest you moderate this input parameters effort. When complete, you could then ask for the model forecasts. At minimum the following input parameter information is required:

-Hiker’s sex, age, weight, height, VO2max, and RER profile. As an alternative to a specific RER profile, I suggest that we leave this up to the modeler to factor in.

-Base pack weight (itemized), clothing weight (itemized), and shoe weight.

-Trip segments Terrain surface by % of trip
1.Soft Snow (14")
2.Soft Snow (10")
3.Soft Snow (6")
4.Loose Sand
5.Swampy Bog
6.Heavy Brush
7.Hard Packed Snow
8.Light Brush
9.Dirt Road/trail
10.Blacktop Surface

-Trip Segments elevation profile by % of trip
1.Moderately level
3.Climbing to a mountain peak

-Trip Segments min F, max F, & rain % by % of trip, and average miles between water sources

The segment information would result in something like this:

1,500 mile trip

1. 70%-Dirt Trail, hilly, min 40F, max 80F, 10% rain, 20 miles to water
2. 10% Dirt trail, climbing to a mountain peak, 70F max, 20F min, 10% rain, 5 miles to water
3. 10%-Hardpacked snow, hilly, 70F max, 30F min, 5% snow, 1 mile to water
4. 5%-Blacktop surface, moderately level, min 50F, max 90F, 20% rain, 10 miles to water
5. 5%-Loose sand, moderately level, 90F max, 60F min, 1%, 30 miles to water

I suggest that the models create forecasts for 3 scenarios: 30 years old male, 30 years old female, and 60 years old male. This will give a broad range of forum participants one of the three forecast categories to most closely relate to.

Edited by richard295 on 11/17/2006 13:54:45 MST.

Bill Fornshell
(bfornshell) - MLife

Locale: Southern Texas
Unsupported/Unresupplied/Thru-Hikes on 11/17/2006 16:26:28 MST Print View

If you want to play with my data here it is as best as I have it.

sex - Male,
age - 66
weight - 150
height 72"
VO2max - 34.1 but based on a weight of 163. My current weight is 150 and my estimated VO2max is now 42.46.
RER profile - I don't have this but I think I know what it is and might be able to get it next week if it is that necessary.

My calorie burn per minute is 6.8.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Unsupported/Unresupplied/Thru-Hikes on 11/17/2006 19:45:47 MST Print View

Bill-I will use your profile as one of the test cases. To do a complete AT analysis, I need someone who has hiked the AT to provide the distances and a summary of the trail segment types and I will build the model. None the less I can model your personal information now.

An RER test shows the mix of fats and CHO your unique metabolic system burns at different % of your VO2max. The test typically costs about $250 if done by a sports club or physiology lab. Without exception everyone shifts to a higher % of CHO burned as their % of VO2max goes up but the starting mixture and rate of shift varies widely. Without your RER information, I can still calculate the C burned for any given trail segment type and be accurate to within 14%.

Without your RER, I can’t calculate your substrate mix as accurately as your calories. Consequently, the optimal food weight you need to carry for each trip segment type is not as accurate as the C rate. The higher the % of fat to CHO you burn in the backpacking MET range, the higher the C density of the food you can efficiently carry. I will use the mean values in the absence of an RER.

The following is your unique metabolic information to assist in your backpacking trip planning:

Name - Bill Fornshell
Sex - Male
Age - 66
Weight - 150
Height - 72"
VO2max - 42.46.

Note that your VO2max is greater than 40 which puts you in the Elite cardiovascular conditioning class for your age range.

Attached is the unique metabolic analysis I conducted for you using a physiology modeling system that I am still developing:

BF AT Analysis

The thin lines are the mix of fuels you will be burning ½ hour into your daily backpacking activity. The thick lines are what you will be burning from about 3 hours until you finish your backpacking day.

The MET numbers are multiples of your unique BMR which is 60.99 C/h. My system is designed to be used in conjunction with any MET table you find on the Web. Assume you planned an AT trip segment to backpack, at an average 3.5 mph, carrying an average 30 lb pack, and travel through hilly terrain. You can look up this activity in most MET tables and find out the value is 8. I put a white line on your chart at 8 METs to assist in this explanation. While backpacking your % of VO2max will average 51%, your % of MHR will average 70%, your HR will be 107 (HR zone 2), your C/h will be 489 and your BMR = 60.99. Note that 489/60.99 determines you MET level.

When in camp your MET level will average 2.5. You can use the fine lines on the graph to also determine your C burn rate and the substrate utilization for camp activities.

After about three hours of backpacking, your system will stabilize at a substrate utilization ratio of 60% fat, 35% CHO, and 5% protein (thick lines). These values should be used to help determine your optimal menu selection.

Your powdered Ensure provides the following nutrient profile per 8 fl oz: Calories 250; Protein (% Cal) 14.1, Total Fat (% Cal) 22.0, Carbohydrate (% Cal) 63.9. Your Carnation Breakfast (Original Dark Chocolate) mix provides the following nutrient profile: fat 7%, CHO 78%, and pro 15%. In sufficient quantities to meet you daily caloric needs, these foods would provide near optimal support for your substrate ratio and calorie requirements.

Edited by richard295 on 11/17/2006 22:24:06 MST.

Sam Haraldson
(sharalds) - MLife

Locale: Gallatin Range
Unsupported/Unresupplied/Thru-Hikes on 11/17/2006 20:09:49 MST Print View

Richard, could you briefly give definitions for the acronyms in your post? RER, MET, et al. The precision of the approach you're taking is outstanding!

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Unsupported/Unresupplied/Thru-Hikes on 11/17/2006 21:47:37 MST Print View

Sam-In laymen’s terms:

RER-This stands for respiratory equivalence ratio. A participant wears a mask and sits on an exercise bike. As they pedal, the mask captures the amount of oxygen they are breathing in and the amount of carbon dioxide they are breathing out. The ratio of these two gases is then used to calculate the fat and CHO percentage being used as fuel. Protein is not used as a fuel source if you are taking in adequate calories. Based on the ratio of fast twitch and slow twitch muscles you inherited, you cardiovascular condition, etc., this set of numbers will vary for each person and sometimes significantly. For backpacking it is normally OK to just use the mean values.

MET-This stands for metabolic equivalent. When you are at rest the energy you burn is referred to you basal metabolic rate (BMR). When you exercise the amount energy goes up to some level. By dividing the energy exercising / the energy at rest the MET rate is determined. For a given activity, the Calorie expenditure and the mix of fuels are being burned are unique for each person. The MET ratio is surprisingly consistent. A large number of hiking and backpacking MET ratios for different speeds, terrain, and pack weights have been analyzed and published by various sources.

Edited by richard295 on 11/17/2006 21:49:58 MST.

Bill Fornshell
(bfornshell) - MLife

Locale: Southern Texas
Unsupported/Unresupplied/Thru-Hikes on 11/17/2006 22:23:41 MST Print View

Thanks for taking the time to work out the data on me.

Remember that I also use
Hammer Perpetuem in all my water at half strength or about 130 calories per 1 liter of water.

On my hike in Georgia last month I used both the Dry Ensure/ Carnation Drink mix for food and the Hammer Perpetuem in my water. This seemed to work really well.

While I am sure I could not do this in 3 re-supplies I might be able to do it in 5.

I did divide the 2175 miles into three segments.
1. Springet Mt, GA to Daleville, VA. 714.3 miles
2. Daleville, VA to Pawling, NY 716.8
3. Pawling, NY to Mt Katahdin, ME 743.9

This could change but it would give you 3 segments.

IF, I was doing this in 5 resupplies I would want to apply a little stratagity according to the terrain. I would try a shorter first section to gain strength and get my trail legs. Then add mileage to each of the middle segments and then another shorter last segment or the Maine section. Some parts of the AT have terrain that would lend itself to higher mileage and could be longer than 1/5 the distance.

I think five resupplies would give me a pack weight of around 40 pounds on day one of each segment. I can't even think about a pack weight of 70 plus pounds. A start date needs more thought and I might have to reschedule a couple of my up-coming medical exams. A start date of 1 April would be a good date for planning at this time. I would also plan between 100 and 110 days to do the hike. It would be nice to do it under 100 days and as the hike progressed that might even happen. Baxter State Park starts letting hikers climb Mt Katahdin on or after 15 May each year. A start date of around 1 April and a 110 days to hike the AT would put a person on Mt Katahdin on or about 19 July.

As an after thought some time also needs to be planned for the four resupply orgies, book signings, pod casts, TV interviews, etc, etc.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Unsupported/Unresupplied/Thru-Hikes on 11/17/2006 22:31:59 MST Print View

Bill-In between planning for your: four resupply orgies, book signings, pod casts, TV interviews, etc, etc <grin> I need one additional key piece of information from you or someone that has done this hike. What is the terrain like? You metabolic rate is the lowest walking moderately level ground (what % of the hike). It goes up in hilly terrain (what % of the hike?), and it is the highest when you are climbing a mountain range to get over a pass (what % of the hike?).

Bill Fornshell
(bfornshell) - MLife

Locale: Southern Texas
Unsupported/Unresupplied/Thru-Hikes on 11/17/2006 22:39:30 MST Print View


I don't think I am the best person to try and answer the terrain question.

John S.
(jshann) - F
Re: Re: Unsupported/Unresupplied/Thru-Hikes on 11/18/2006 08:07:06 MST Print View

Richard, what is your background? You have a very analytical approach to problem solving, so I was figuring you are a scientist?

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Unsupported/Unresupplied/Thru-Hikes on 11/18/2006 09:31:49 MST Print View

John-I am not formally trained in any of the disciplines that I post to the forum on. My degree is a BS in Information Systems Management. My resume includes 14 years in software engineering followed by the remaining time in computer/software marketing and sales.

The forum topics I contribute to contain primarily self learned information. Take my theories with a grain of skepticism and challenge anything that appears wrong. Not that I needed to make that point <grin>.

Edited by richard295 on 11/18/2006 09:33:01 MST.

Sam Haraldson
(sharalds) - MLife

Locale: Gallatin Range
Unsupported/Unresupplied/Thru-Hikes on 11/18/2006 12:22:35 MST Print View

Do the folks interested in this thread have any good bookmarks of some common MET ratio tables located on the Web?

I'd be interested in applying my personal statistics into a table to see what my fuel consumption needs would be throughout a day, week, month.

Edited by sharalds on 11/18/2006 12:30:44 MST.

Roman Dial
(romandial) - F - M

Locale: packrafting NZ
Re: Re: Unsupported/Unresupplied/Thru-Hikes on 11/18/2006 14:14:32 MST Print View


Can you work your model backwards? For instance, what parameters would sastisfy walking the PCT across Oregon and Washington, say, in a month and a half, without resupply?

I guess what I am asking is, if given age, and the other physical parameters that a person is "stuck with", could you tell us what level of exertion or effort will be required to do a big challenge like 1100 miles in 6 weeks?

It would be interesting to know......

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Re: Re: Unsupported/Unresupplied/Thru-Hikes on 11/18/2006 16:05:56 MST Print View


Based on what you accomplished during the Artic 1000, your capabilities are obviously at the very elite end of the athletic spectrum… congratulations for your achievement. I don't have your (age, weight, height, and VO2 max) stats. In the absence of this information I will use Ryan’s stats for your analysis. I will work backwards and then post the results within the next couple of days.


Bill Fornshell
(bfornshell) - MLife

Locale: Southern Texas
Unsupported/Unresupplied/Thru-Hikes on 11/18/2006 18:51:10 MST Print View

Food and Related Items for the Hike:

Since all my food has to be liquid, well I can eat a few soft things if I am careful, I have an interest in higher mileage between resupply stops. I can't just walk into many stores and buy Dry Ensure. To do an AT Thru-Hike or a very long hike of any kind I had planned to do a lot of mail drops. In the early planning I thought about just doing my resupply when I walked through a place with a Post Office or a store that would hold a food drop for hikers. The idea of going into town after town has very little interest to me as I can't eat the kind of food I would find there.

This idea of only a few resupply stops wither it is 3 or 5 or 10 plays into my food needs. I am sure I can not nor would I even try a 3 resupply AT Thru-Hike "this time". I might think about 5 resupply stops. That would give me a average food weight at the start of each of the sections of about 33 pounds. I was surprised at the large volume that amount of food was going to take up in my pack. My Dry Ensure packs a lot of calories in a small package. A one serving size is 282.5 calories (2.29 ounces) will pack into a coffee filter and be about 2" square for planning. The zip lock bag in the picture is 10 servings or food for one day (2825 calories). I am using Hammer Perpetuem in all my water and that will add about 520 more calories a day for a total of about 3345 calories a day.

Nutritional information for Dry Ensure:

Nutritional information for Hammer Perpetuem:

Multi-Use in action:

On the second half of my hike in Georgia last month I started packing my Dry Ensure in large paper coffee filters. It made my every 90 minute food stops go much faster. The paper coffee filters also turned out to make great TP. That saved a little weight and got rid of the filter. The paper filter will burn nice if I need something to start a fire with.

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Unsupported/Unresupplied/Thru-Hikes on 11/19/2006 01:47:25 MST Print View

Bill, that may be yet another "Fornshell-First"!! Very clever dual-use of the coffee filters.

Thom Kendall
(kendalltf) - F

Locale: IL
Re: Unsupported/Thru-Hikes on 11/22/2006 15:33:04 MST Print View

I am new to this lightweight camping but I think you guys and gals are making this to complicated. What you need is an increase in knowledge and then you can go unsupported for long lengths of time. If you know your camping area you can learn the edible plants in that area. The food you carry can help supplement this gathering. It is now illegal in most places but at one time you could also hunt and set snares for meat.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Unsupported/Thru-Hikes on 11/22/2006 15:53:04 MST Print View

In summary this analysis, concurs with Ryan’s assessment that the AT can be done unsupported in three segments by using ultra-light backpacking equipment and techniques.

The first chart is a composite of 4 simulations I conducted to answer the question, “What is the theoretical maximum unsupported backpacking segment distance for the AT?”

If this activity were an Olympic event, the record unsupported segment would stand at ~ 1035 miles. The average winner each year would probably be closer to the Artic 1000 team’s simulated results than the record holder’s.

The exceptional three athletes, who participated in the Artic 1000 event, would achieve ~ 921 miles. Their physiological characteristics, combined with there backpacking knowledge, are quite exceptional.

The average male is defined by ISO 8995 (2004). I have defined him in the simulations as Average 30 Year Old Male. He would be able to achieve ~754 miles. I also attached a physiological profile from the output of my simulator for this theoretical individual. I believe that the average BPL forum participant is closer to this profile than the other three.

I used Bill Fornshell to represent the physiology of an exceptional 66 year old. Bill’s VO2max of 42.46 is in the Elite class for his age range. Bill's number is ~742 miles. Obviously any individual with special diet requirements should consult their physician before attempting what the model suggests.

Bill defined the AT segments as follows:
1. Springet Mt, GA to Daleville, VA. 714.3 miles
2. Daleville, VA to Pawling, NY 716.8
3. Pawling, NY to Mt Katahdin, ME 743.9

Each segment is less than what could be achieved by the average 30 yr old male using only what is in his pack. As long as he paces himself to the specified exertion rate, he shouldn’t require excess body fat.

In order to maximize the model execution time, I used table lookups extensively. The table values are rounded and consequently some totals will vary a few % from just adding up the reported substrate utilization.

This AT model is a prototype product which I designed. This is its first set of output scenarios. It is labeled as revision .1 to reflect the prototype status. If you see an unreasonable equipment assumption, suspect an error, or you have a suggestion for presenting the information more clearly, please email me with your suggestions. I will attempt to incorporate them, rerun the simulation in question, and post the new result. Each model revision will increase the revision level by .1. Only after a real AT unsupported segment attempt closely matches the model results would I feel justified to changing the revision level to 1.

Avg Physiology

Edited by kenknight on 04/28/2007 13:25:58 MDT.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Unsupported/Thru-Hikes on 11/22/2006 16:13:05 MST Print View

Chart by itself

Sam Haraldson
(sharalds) - MLife

Locale: Gallatin Range
Unsupported/Unresupplied/Thru-Hikes on 11/22/2006 16:52:44 MST Print View

Richard -

Those are some very useful charts. You've given a nice broad range of individuals to base oneself against. I haven't heard many women chiming into our conversation but if they did they may feel left out.

Below is a Web site I found that suggest ways of calculating ones V02 Max.