runners: water weight loss

i am just curious as to others water weight loss when they run, specifically people who run a lot.

This happens to me a today...

weight before run : 202
weight after run: 196

thats 6 pounds of water weight, and one time i measured 8 pounds of water loss.

(this was a 10-11 mile run at a very slow pace) about a 1400-1500 calorie burn

so runners does this happen to you when you do long runs? or am i some freak :P


  • es2189
    es2189 Posts: 142 Member
    I don't do runs that are that long (yet), but after a 5-6 mile run, I usually am down 2-3 pounds. Then I drink a couple gallons of water and I'm back up!
  • AmyRhubarb
    AmyRhubarb Posts: 6,890 Member
    I haven't weighed myself pre- or post-run to check it out, plus my longest run to date is just over 6 miles. But I have a friend here who runs in the Arizona summers, and he has posted about losing several pounds in water after a long hot run.

    You're not a freak. :tongue:
  • mightymac
    mightymac Posts: 56 Member
    yip i'm always lighter after my run, the longer the run the more water weight i lose, it's all the sweat that drips of lol
  • nphect
    nphect Posts: 474
    thanks guys
  • algebravoodoo
    algebravoodoo Posts: 776 Member
    Yes, this happens to me frequently, especially in the summer heat! Unlike so many "Southern Belles" I do not glow, glisten, perspire or any of the other euphemisms... I sweat like a man! We are talking puddles :blushing:
    Weigh pre-run and post-run then drink back to your normal weight, but not all at once. Figure about 16 ounces water per pound of loss. Since I know I am going to loose about 1.5 - 2 lbs over a 60 minute run, I try to drink about 1/2 liter every hour during the run so I am not down by so much afterwards. And remember, fruit and such can count as water post-run and helps balance electrolytes!
  • Azdak
    Azdak Posts: 8,281 Member
    In an experiment done by one of my colleagues in grad school, I observed an athletic young guy (muscular, but BF% <10%) lose 7lbs of water just sitting in a hot tub for 30 minutes.
  • emtjmac
    emtjmac Posts: 1,320 Member
    It happens to me after every run.
  • TrailRunner61
    TrailRunner61 Posts: 2,505 Member
    I don't usually weigh myself before and after so I don't really know. I can easily tell when I need more to drink though, because my calves will start to cramp and I'll stop sweating. You don't want that! If it's a problem for you, try to find one of those camelback things to take some water with you to sip.
  • cad39too
    cad39too Posts: 874 Member
    Yep, I'm always lighter after a long run - used to have the same thing happen when I did spin classes too.
  • meerkat70
    meerkat70 Posts: 4,616 Member
    yep, I've lost as much as 8lb on a long run.
  • When you increase your training to gear up for your goal race, your body begins to store more water to repair damaged muscle fibers and to deliver glycogen to the working muscles. Likewise, you may even be drinking more water to supplement the miles and ensure your hydrated. All this water adds pounds to the scale, but isn’t indicative of your actually weight loss.