How far would you get

It looks like we're assuming a flat road. It would probably be best to try to find some shade (or bring your own) and sleep during the warmest part of the day and walk at about 15 minute miles the rest of the time (may be tough with a full pack). Traveling about 15 hours a day, that's about 60 miles, and you could probably carry enough food and water for about 5 days, so I'll say about 300 miles.

Interesting question. Bonus first: Given the extremes I'd think a smaller person might have an advantage, and of course, given specificity of training, I'd tend to think race walker or runner if we're talking level ground. I really don't know which is more efficient although I recall reading that walking in general uses fewer calories per mile than running (don't know about race walking). Of course, you wouldn't get as far per unit of time, and as you'd have to carry your own gear, basic body needs might be the killer (vs. exhaustion).

What would I carry? Probably water spiked with a 6% carb solution and electrolytes, and also some dried complex carb thingie with modest amounts of protein and fat. As far as commercial stuff, that'd be your basic sports drink and granola bars. Travel mostly from dusk to dawn and hide under your clothes to sleep in the day. You'd probably need 3-5000 calories/day anyway (assuming you can draw off body fat) and several liters of water/day. I think a couple hundred miles would be VERY tough (200 miles * 100 cals each = 20,000 cals)! My guess is that the first day wouldn't be so bad, but as dehydration started to set in, you'd be dropping in performance each step. I think the weight of water is what would ultimately limit you.

Then again, if there was water nearby, I'd carry a hikers microbial water purifier and make as much as I want/need! A book on local edible food stuffs and a few survival items would take you a long way as well. Of course, this is all out if we take "eat/drink only what you carry" literally.

Well since I took Ex. Phys. in Germany I didn't get a chance to take your final exam. Although I do remember a conversation on the way to one of the meets and Conaire had the best answer yet.

If you ask Conaire....He'd drink as much water as he could before the start and carry two gallons of water, one in each hand and nothing else. He'd run all night and sleep all day. What did he figure about 50 miles per day or so, and he figured he could go about a week. 350 miles.

How about the guy that was going to carry lots of tunafish! Because it had water in the can or something like that.

The road is flat, humidity is low and you may not receive any fluid or food from outside sources (remember, nor rain or moisture on your clothing to drink, only what you start with). A serious thought may be how many pounds of supplies do you think you would start off with. Naturally a big person could carry more and would also sweat more. A final stipulation is that you must end your trip once you have dropped body weight by 6% of your starting weight (I'd say 8%, but that is getting a little risky). Live it up. Hint: Actual Extreme answers (1) 18 miles and all supplies would be gone. (2) 560 miles and still carrying some supplies

I would take water and just a little bit of nuts,fruit, and granola. If you start with about half your body weight in supplies (mainly water), you could probably cover about 5 miles per hour. If you traveled only at night, I think you might be able to keep going for three or so nights before you ran out of water and started to dehydrate. Water will definitely be your limitting factor, though.

I wouldn't take any supplies. I think I could cover from the Northernmost tip of Alaska to about Panama (not sure how to get around that canal... Am I allowed to ride a boat?). How many miles is that?

3 miles

Yeow, 560 miles? I was thinking about this this morning. I was thinking along the lines of 3 liters of water/day. Then I started adding up the days. I've done some backpacking over the years, and I can't imagine running any distance with a 40+ lb. pack. That's around 20 liters of water. If you could squeak 2 liters/day and do 50 miles/day, that would put you at 500 miles. You'd be walking the first few days though. Maybe not running at all would be better as you sweat less. (Although having done some Fall hiking in the Adirondacks, I will atest to the fact that you can produce quite a bit of sweat in 45 degree weather while walking and wearing a 20 to 30 lb. pack).

Of course, 500 miles is on the order of 50,000 cals for the average sized male, or around 14 lbs. of fat if you could get by on just some carbs disolved in the water. (What's that old saying about fats burning in carbohydrate furnace?) I guess this person had better not be _too_ thin.

If this was a survival thing (do or die), I think I'd seriously consider "recycling" my urine. (Gag me...)

#1)154 pound person could carry up to 33% of body wt. or 50.8 lbs of a water/carbohydrate/electorlyte mixture(Gaterade).

#2)72 miles covered before ending the trip due to more then 8% water lost.

#3)Med-sized endurance trained male.

OK, I've been thinking out loud here long enough. While I was proctoring my final exam in Linear Electronics this morning I had a few minutes to spare so I did a computation based on what I know about ME (not exactly scientific, but good enough for the purpose at hand):

1) I can probably carry a 40 lb. pack a pretty good distance over level terrain and average 3 MPH (extrapolating from hiking experience).

2) My basal metabolism requires around 2000 cals and at least 1 liter of water per day.

3) A 6% loss of weight would translate to almost 9 lbs.

4) I require about 4 oz of water/mile when working out under "room temperature" conditions (my basement, on a treadmill) to stay hydrated. (No, I don't drink this much while running.)

Assuming a workrate of 100 cals/mile and the ability to traverse 40 miles/day (13 hours at my hiking rate), my daily requirements work out to about 6000 calories and 12 to 14 lbs of water. Thus, if I packed about 20 liters of water and around 5 lbs worth of mostly carb "dried food product", I should be able to last 3.5 days, or 140 miles. This assumes a starting pack weight of about 45 lbs, most of the weight lost as water, and about 2-3 lbs lost as fat for fuel. (I'm assuming about 50/50 carb/fat burn.) The first 2 days would likely be all walking, with possible running after that as the pack lightened up. I imagine that willpower would be paramount in the final stretch. I think this number is optimistic.

And if anyone is thinking of setting up this scenario as a research project for a degree in physiology, count me ... out!

A question about urine recycling.

I don't know much about physiology, so perhaps someone who does can help me out here.

I would imagine that in a competition such as this, that urine recycling would be a vital component. How the urine was recycled, however, would have great effects. If you re distributed your urine evenly throughout your entire remaining water supply, the salts in it wouldn't be too much of a detriment I'd imagine.

At what point would the water/urine mixture become too concentrated to be useful?

Similarly, I guess, if it was humid enough that your sweat was not all evaporating you could try and squeeze that in to stretch your water supply.... Does make it that much less pure water though.

Could recycling those salts be beneficial to some extent?

There certainly is a limit to this without filtration. I don't have the background to give numbers, but I will relay a story from many years ago. It seems there were some college chemistry students who had a taste for what we might charitably call "chemical amusement aid". They would experiment with certain chemicals using their bodies as filtration/concentration devices (i.e., the took the drugs, then drank their urine to see if the concentration and thus the effect, increased). I use this story as proof that a little knowledge can be sometimes be dangerous!

According to the U.S. Navy, some years ago they stated one could drink one's own urine in a survival situation (with no other source of water) for perhaps 2-3 days, before it "becomes brackish".

I guess I never understood how you could do this at all, since your body is filtering out all the "junk" in urine...no telling what's in there!

Good to hear some serious responses. I often wonder why this hasn't been on reality TV yet (cheating would be the main problem -- each competitor would need an official). I've given this as a 2-week take-home final in grad ex phys classes and many of you do as well as many of them did. Some absurd answers to part of the problem. "I'd take only cans of tuna fish to eat, cause I love tuna." "I'd take 2 or 3 pairs of socks and shoes." "I'd take a light sleeping bag for sleeping at night." This last response indicates traveling in the heat of the day. I initially designed this to see who was the best endurance athlete -- runner, cyclist, mountain climber, race walker, other? Since it would undoubtedly be a walk it sort of eliminates the need to run in the event. Check the research (Army stuff for one) and this will help decide how much fluid is lost in sweat, which could be enormous for some people.

Here's an item that may be of interest. I lifted it from today's RWOL:

Former U.S. Marine H. "Mike" Monroe, has helped more than 250,000 Americans paralyzed through spinal cord injuries by raising $30,000 for competing in the gruelling Marathon des Sables in the Western Sahara Desert. The MdS was held April 6-12, in six daily stages: an 18-miler, a 22-miler through the sand dunes, a 23-miler, a 50-miler, a 26.2-miler, and a 13.1-miler. Marathon participants carried all their own food and gear throughout the race, no easy feat considering that Mike's pack weighed in at 22 lbs, without water, on day one of the race. Mike, who sustained himself on 9 liters of water and just over 2500 calories per day, finished 149th overall and 4th among the American competitors, completing the Marathon with a cumulative time of 34 hrs and 13 minutes.

jtupper wrote:

I often wonder why this hasn't been on reality TV yet

This reminds me of Steven King's "The Long Walk"... in which walkers set off with no supplies and had to keep a certain pace. When they started to slow down, they were shot. This was considered entertainment by the society. Although, this not nearly so extreme, it does sound a bit inhumane. 6% body fat loss is kind-of a lot. I would think the health risks would be too great for this to ever be a plausible reality show, just a hunch though.[/quote]

Assuming most people bring about the same supplies and use the tactics wouldn't it come down to which athlete's body is best suited for the specific physical demands, similar to in a normal race. It's pretty obvious travel in the coolest part of the day is essential, as well as walking being the locomotion of choice. So supplies and tactics equal what then become the deciding physiologic factors? Fat utilization? Do some people use water more efficiently than others?

jtupper wrote:

I initially designed this to see who was the best endurance athlete -- runner, cyclist, mountain climber, race walker, other?

Is there really a "best" endurance athlete? I would think that each kind of endurance athlete is best suited/trained for their specific event. In this I would think walkers/runners would have a BIG advantage.

I never watch reality shows... how extreme do they get? I assumed that there is no real health risk to participants... But maybe we're moving towards gladiator like mentality. Just for entertainment? Bugs me for some reason, but so does boxing...

Sorry getting off-topic ;o)

This is a great thread. Easy to ponder over this one quite a bit.

I would wear a pair of running shorts and medium weight goretex pants. Also a light weight goretex t-shirt and a medium weight goretex jacket that had plenty of pockets. I'd wear running shoes (obviously) and also have a stocking cap. 45 degrees is cold enough that you would need to be well covered. And then I would sleep under the clothing during the middle of the day.

For food and liquid, I would try to carry around 8 liters (around 2 gallons) of Gatorade. I would get 2 of those Camelbak's, wearing one on my back and one on my front. I saw ones that carry 100 oz each, have room for extra storage and only weigh 1.6 pounds empty each. For food I would bring 30 Powerbars and 20 Gu packets, fitting them into the packs. Also I would bring 2 decent sized (each 24-32oz - around a liter) water bottles with Gatorade I would carry in my jacket pockets. I figure the Powerbars and Gu would weight 6-7 pounds, 256 oz of Gatorade would weigh around 16 pounds. The weight of the packs would bring it to around 26 pounds of "stuff" not including the clothing.

3 miles an hour seems like a reasonable rate of travel. Doing this for 16 hours a day (6pm to 10am) would give me 48 miles a day. Walking steadily during the night should help limit the amount of fluid I would have to intake. I would drink about 64 ounces of Gatorade and consume 7 or 8 Powerbars and 5 Gu packets each day. I think I could do this for 4 days, covering between 190 and 200 miles. Finally, I think I would try to bring a picture of a really hot girl. For several weeks before I would look at the picture and tell myself she would be waiting for me at the finish. So, once I was 3 or 4 days into the trek and started hallucinating, I would start envisioning her, causing me to keep on going at all costs!

I had a question for jtupper. I would like to get rid of the weight loss restriction. Since this is all hypothetical anyways, I would like to be able to have people lose more than the 6% of their weight. If someone wants to push themselves close to death, more power to them. I think the only condition is that the person lives for it to count as a record. So, if you go 425 miles but die at the end, you lose. I know it sounds ridiculous. I am interested to see how far one could go in these controlled situations but have it be almost a life or death scenario where we see what is possible if you have nothing to lose. Is it possible for a person to lose more than 6% or 8% of their body weight and still keep going? I would guess that has happened in survival stories.

I think the best athlete for this would be a medium build ultramarathoner. Someone who ate a ton for a few weeks leading up to it, packing on an extra 10 to 15 pounds of fat reserves they could burn off during the trek.

You have made a realistic approach to this. I had originally been willng to declare the winner the one who got the farthest, no matter how much weight lost. Just tape a piece of chalk to each forehead and when you fell to earth you marked your spot for final measurement. There would have to be some cut off and i figured 6% was healthy enough, to allow another attempt if you so desired.