Nutrition question for long day-hike.

[Little Rickie]

Reading through all the responses I think the key question I'm wondering about is to what extent can you rely on burning your own body fat to fuel a hike.

Does anyone know how effective manipulating the system is through training, nutrition, drugs (caffeine is still a drug isn't it?) and pace setting in skewing the fat:carb fuel ratio towards fat?

I'm pretty sure I read something in Chasing the Antelope by Bernd Heinrich about migrating birds and insects and fat for fuel. (I lent the book to a friend runner and never got it back.)

Acording to my Polar HRM at 65% of my max heard rate I'm burning 55% of my cal from fat. The lower the rate the higher % fat burn. No matter what you need carbs to burn fat.

Now if your a highly trained aerobic person I'd defer to their experience since I am better at storing fat than burning it..

 

[DougPaul]

Acording to my Polar HRM at 65% of my max heard rate I'm burning 55% of my cal from fat. The lower the rate the higher % fat burn. No matter what you need carbs to burn fat.

Such numbers are at best averages that fail to take individual variation into account. At worst, they are wild guesses.

I have seen graphs of typical fat and carbo consumption as a function of some indicator of exercise level. The fat consumption rate (per time) is basically constant over a wide range of activity levels and the variation is all in the carbo consumption rate. Thus for a given activity the total amount of fat consumed is proportional to the total time and the percentage of fat consumed decreases at higher activity levels only because the carbo consumption rises.

One can conclude from this that one can generally hike farther by slowing down to reduce ones carbo consumption.

Doug

 

[Snowflea]

* Just water is allowed
* Any beverages are allowed including powdered drinks like Emergen-C

A guy fastpacked the 211-mile John Muir Trail last year in a little over 5 days using only powdered drink mixes for sustenance. See:

http://www.backpackinglight.com/cgi...ums/thread_display.html?forum_thread_id=15733

(Scroll page down about halfway.)

 

[Caveman77]

Neil - check out this little online calculator...with your weight, distance and elly gain it shows how many calories you'll need.

Scott

If you plug in 0 miles, then it comes up with 0 calories. So it's definitely not accurate. Must be ignoring basal metabolic rate.

I'm going on a 16-18 hour dayhike and figure I'll burn about 10,000 calories during the hike.

10,000 calories sounds like an overestimation to me, unless you're carrying a heavy pack, running nonstop, or weigh a lot.

My last walk was 42 miles, 4200 feet elevation gain, in 16 hours. I got by fine with three normal meals: PBJ sandwich, yoghurt, apple, cheese sandwich, two cups tortellini, handful of chocolate chips and almonds. Had lots of pasta the night before and pancakes the morning of the walk. That's somewhere between 2000-3000 calories. Weighed the same after my walk as before: 145 lb. I did drink 7.8 L water!

Um, no one asked yet... so what is this hike that you'll be hiking?

 

[Neil]

Acording to my Polar HRM at 65% of my max heard rate I'm burning 55% of my cal from fat. The lower the rate the higher % fat burn.

So you should tell your wife when she sees you slothing around watching TV that in actual fact you are at your most efficient level of fat burning activity.

10,000 calories sounds like an overestimation to me, unless you're carrying a heavy pack, running nonstop, or weigh a lot.

This could very well be. I based it on 10 cals a minute intensity or 600 cals/hour over 18 hours. I might end up (should actually) taking less time and maybe I'll only be doing 8 cals/minute, alltho' I'm pretty sure it'll be closer to an average of 10.

I'll let you know plenty about the hike after I've done it. However, it's a bushwhack in the Dacks, 6 miles on trail and 13 miles (as measured in Topo) of whacking with 5000 feet elly gain and loss. In the area in question it's pretty tough to average 1 mph and it's strenuous going. Lots of heart pounding and heavy breathing. .

I weigh 185 (nekked, first thing in the morning with all body cavities empty) and will have about a 10 pound pack.

Irrespective of the number of total calories burned, which I will never know anyway, my main interest is in relying as much as possible on fat burning for fuel. My strategy, after reading this thread will be: start slow and taper.

 

[Mats Roing]

To make things simple - just buy a 4.4 lbs bag of this and start hiking - it's pretty amazing how much quality content is in here. It's way better than most things you can buy for humans in a regular food store:
http://www.karmaorganicpet.com/products/default.asp?id=1503

 

[leaf]

That's great, Mats. Snack on this for lunch and soon you'll be dander-free!

 

[Little Rickie]

Such numbers are at best averages that fail to take individual variation into account. At worst, they are wild guesses.
Doug

I don't think my Polar HRM is that far off. I enter my wt, age and fitness level. It even measures my fitness level. I've used it a lot for a few years under different conditions. I like it and seems to work well for me. I do burn more fat at low intensity and burn more carbs as I increase my intensity.

Question. Are there any Polar users on the forum that would like to share their experiences?

 

[Little Rickie]

So you should tell your wife when she sees you slothing around watching TV that in actual fact you are at your most efficient level of fat burning activity.

Interesting thought and that may be true but I'm usually liquid carbo loading while I'm slothing. I'll have to try this sometime but my cal burn rate may be too low to measure.

Tell me a funny story. I know you got a few.

 

[Neil]

Question. Are there any Polar users on the forum that would like to share their experiences?

I used to wear my Polar HRM every time I did some exercise, downloaded the data onto my computer etc. etc.

I also did an aerobic threshold (and other parameters) test in a lab because I didn't trust the so-called average numbers (as in 220-age = max HR etc.)

What was interesting was that based on using the HRM and training a lot and monitoring how I felt during and after workouts my estimations for my lab values were very close to the real values.

I almost never use my HRM any more. I go by feeling, which Sally Edwards says will always result in a less intense training session.

I have taken it on some hikes and my values are all over the map and much lower for a 12 hour hike than for a 45 minute aerobic threshold session. I wonder why.

The bible for a lot of this stuff is (or used to be) Better Training for Distance Runners

Here's to becoming better butter burners.

 

[Little Rickie]

It's a tool that helps you learn about yourself. If I go by feel I do exercise with less intensity. The HRM keeps me honest.

I stopped using it on climbs because I got scared about how often and for how long I would max out (red line+) my HR on steep climbs.

It's not that I'm bad at butter burning, it's that I'm better at butter making.

Now how about a fun story.

 

[bikehikeskifish]

One important use of the HRM is to tell you when you are going TOO hard. On rest / easy / "recovery" days, it's a good excuse to take it easy - blame it on the HRM. With time and experience, you can get pretty close to the right "zones" by feel. The HRM helps you learn the right feelings, and makes you that extra little bit more accurate.

Tim

 

[DougPaul]

To make things simple - just buy a 4.4 lbs bag of this and start hiking - it's pretty amazing how much quality content is in here. It's way better than most things you can buy for humans in a regular food store:
http://www.karmaorganicpet.com/products/default.asp?id=1503

Check the local agricultural supply/zoo supply/feed store to see if they carry dry "human chow".

Probably in the same aisle as the monkey chow...

Doug

 

[DougPaul]

I used to wear my Polar HRM every time I did some exercise, downloaded the data onto my computer etc. etc.

I also did an aerobic threshold (and other parameters) test in a lab because I didn't trust the so-called average numbers (as in 220-age = max HR etc.)

Those average HR rules-of-thumb are way off for me. My max is ~200bpm and I'm well over 20 years old. (More like 3 times 20...) My (pragmatically measured on a bike) aerobic threshold is somewhere above 90% (180 bpm) of my max. I've been told by a doctor that I just have good electrical wiring in my heart. (Max heartrate is largely determined by genetics and age.)

What was interesting was that based on using the HRM and training a lot and monitoring how I felt during and after workouts my estimations for my lab values were very close to the real values.

I read some books on exercise, bought an HRM, and learned that I can also tell just as much by how I feel as I can from the HRM.

I almost never use my HRM any more. I go by feeling, which Sally Edwards says will always result in a less intense training session.

I only use mine on my bike and only as a monitor, not to control how hard I ride. These days I generally ignore it more than I use it.

Doug

 

[Oldsmores]

...I also did an aerobic threshold (and other parameters) test in a lab because I didn't trust the so-called average numbers (as in 220-age = max HR etc.)
...

I remember reading an article about the source of the "220 - age = max HR" guideline. It was apparently based on an extremely small sample, and there are very wide variations. I know that it's off for me (age 55), as I regularly exercise at 165 - 175 bpm, and my max is somewhere around 200. If I follow the AHA target rate guidelines (83 - 140) I'm not working very hard. Heck, I can get to 83 in the recliner watching Charlize Theron in a G-rated movie...

 

[jfb]

Question. Are there any Polar users on the forum that would like to share their experiences?

My HRM is an inexpensive Sigma Sport model and I use it to maintain my heart rate in the fat-burning zone as described here.

 

[Little Rickie]

My HRM is an inexpensive Sigma Sport model and I use it to maintain my heart rate in the fat-burning zone as described here.

Great link!

My target is 75%, which is just what I'm working on and while working up to an hour 3-4 times a week.

 

[Neil]

Back on topic.

I went out and did the hike but only got through 60% of it in 17 hours. It varied from an easy 3/4 mph pace to crawling (literally) along at a snail's pace while pouring sweat with pounding heart. It was a full body workout and I had sore back, abdominal, inner thigh muscles when I was done.

Anyway, while hiking I drank most of my home-made goo, ate a handful of soy nuts and mixed nuts, ate one cliff bar and 2 squares of nougat. I drank close to 8 liters of water. I tried to keep my level of exertion down to a reasonable level sustainable for such a long time. The day before I ate a huge steak and 2 baked potatoes washed down with 4 bottles of beer. I drank 2 cups of chocoate milk while driving to the trailhead.

I survived and was had enough fuel in the tank to do a 4 hour walk up to Lost Lookout above Beaver Meadow falls the next day.

Trip Report

 

[Little Rickie]

So how many cals do you think you packed on includung supper before, during and after the climb? I'm thinking you stored some, ate some during the activity and replaced some with a meal afterwards

Any energy lows during the hike?

 

[Neil]

So how many cals do you think you packed on includung supper before, during and after the climb? I'm thinking you stored some, ate some during the activity and replaced some with a meal afterwards

Any energy lows during the hike?

Probably took on 1500 the night before, and 1000 max during.

I'm guessing an average burn rate of just under 10 cals per hour over the 17 hours so I'm suspecting I burned up a lot of fat and some protein on the hike.

I found it hard to eat. No appetite.