Wednesday, June 22, 2011

How much liquid do you need to drink?

Today I was doing some field work to help out one of the people who works for me.  He went on a family vacation and has been off for three weeks.  I was in a group of four and we spent the day hiking - working but still being outside and having fun.  When people think of San Diego County they picture beautiful beaches, Sea World, a fantastic park, and lots of things to do. People don't realize that once you get away from the ocean it is hot and dry.  Not quite desert like, although there are parts of the county that are in the desert. 

Today we weren't quite in the desert but still hiking in an area without any trees and lots of heat.  It was close to 100 degrees.  In the afternoon the wind picked up so our sweat was able to cool us down very well.  I'm glad I don't live down here but working in weather like this is a good reminder that we may be put into a situation that we are not familiar with or that we truly don't like! 

I don't mind the heat but wearing a couple layers of clothing and carrying my pack wasn't the way I'd like to spend it.  Sitting around a swimming pool would be more like it!  But work had to be done.  Since we were never going to be further than a mile and a half from our trucks we didn't worry too much about overheating.  We were away from the trucks for four hours.  During this time we walked four miles.  We also drank a lot.  I was hydrated prior to starting the hike.  I didn't carry my camel pack today, instead opting for plastic bottles.  During my four hours I drank 5 -20 ounce bottles of water and three 20 ounce Gatorades.  160 ounces total.  This is five quarts of liquid or more than one quart per hour.  That's less than I should have had but still not too bad.

One of the members of our group bragged that he hydrated himself up and drank five bottles of water prior to heading out to the field.  It took us over an hour driving just to get to the project.  When we were out there he drank two bottles of water.  He was worried that we weren't drinking enough but that he was fine.  After we completed the project we drove the hour back to their office.  When he got out of the truck both legs cramped.   I guess he wasn't so hydrated after all.  The rest of us were fine. 

We are repeating this trek tomorrow.  We will be hiking about a mile away from this project and the weather is supposed to be a little cooler.  I'll make sure I drink enough.  We talk about needing to store a gallon of water per day for drinking and cooking and a gallon for other needs.  That may be fine if we aren’t doing anything but hanging around.  Today we didn’t do any real physical work other than walk around in hot weather carrying heavy equipment.  In four hours I drank more than a gallon.  I wonder how much I would have needed if I was working in the garden or fixing fences or doing other heavy physical activity?


  1. On a recent 7 hour trail run I downed 120 ounces of fluid and was hydrated well. I am always hydrated so I didn't have to play catch up. Electrolytes are also very important with activity, you are not just losing water with exertion.

    Keep a supply of powdered Gatorade and other hydration tablets with your water supply. It's amazing what you lose with just sweat, and how it can really put you down for the count if you don't rehydrate and replenish.

    Everyone should toss on the BoB (as it sits and as you are, don't prep for it) and go for a 5 hour (10-12 mile or more) hike, see if what you have in the bag, or can find and filter, is enough to sustain you and the exertion levels you are putting out. The average person will lose 25-40 ounces per hour with exertion, and over 70% of Americans are chronically dehydrated. Mild dehydration will slow your metabolism as well as cause nice fun things like back and joint pain. That diet soda or iced tea isn't helping at all, it's actually trying to kill you slowly.

    Knowing in advance is another step in being prepared. Don't wait until it's too late.

  2. How did the second day work out? I find the amount of coffee and alcohol during the day makes a difference also.