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Sweat rate

andysport1
andysport1 Posts: 592 Member
edited November 2024 in Fitness and Exercise
For 3 days I've weighed in at 15st 3lb I'm dieting, low calorie, I swam this morning 30 mins 550 cals, I've drank 1500ml of water plus 1000ml of squash then I went for a run 500ml of squash, then 750ml of water afterwards then jumped on scales 15st 0lb. Looking at online calculators my sweat rate is 2750ml / hour "surely this can't be correct" ?

Replies

  • Machka9
    Machka9 Posts: 25,877 Member
    I've exercised most of my life and have done a whole lot of exercise in that time ... and it has never even occurred to me to calculate my sweat rate.

    As long as I'm still sweating on a hot day, I'm good.
  • Royal1954
    Royal1954 Posts: 64 Member
    I've never heard of a sweat rate.
    What's a proper sweat rate?

    What are you supposed to do, match your water intake with your sweat rate?
    What's next - maybe they'll also have you measure your internal body
    temperature to see if that correlates with a sweat rate?

    I make puddles and little streams of sweat on these cardio machines at the gym.
    Yeah, I'm one of those guys.
    Half my gym bag is dedicated to handling perspiration.
    Never thought to measure it.

    I drink a liter of water before the gym, during gym, and after gym.
    And then I'm drinking all the time.
    My goal is that my pee is nearly clear/slightly yellow.
    That's it, no measurements, no counting, no intake analysis or output analysis - except color.
  • rybo
    rybo Posts: 5,424 Member
    Sometimes marathoners and other endurance athletes calculate a sweat rate. Pretty much you need to weigh yourself, exercise & reweigh. Preferably without drinking or eating anything. It's only a very rough estimate and can vary based on a whole host of factors.
  • TavistockToad
    TavistockToad Posts: 35,719 Member
    andysport1 wrote: »
    For 3 days I've weighed in at 15st 3lb I'm dieting, low calorie, I swam this morning 30 mins 550 cals, I've drank 1500ml of water plus 1000ml of squash then I went for a run 500ml of squash, then 750ml of water afterwards then jumped on scales 15st 0lb. Looking at online calculators my sweat rate is 2750ml / hour "surely this can't be correct" ?

    Why do you want to know?
  • Rammer123
    Rammer123 Posts: 679 Member
    rybo wrote: »
    Sometimes marathoners and other endurance athletes calculate a sweat rate. Pretty much you need to weigh yourself, exercise & reweigh. Preferably without drinking or eating anything. It's only a very rough estimate and can vary based on a whole host of factors.

    We used to do that in school during preseason and had to drink back the weight lost in oz. If you lost more than 5% of your weight, you couldn't train in the afternoon.
  • Alisonswim46
    Alisonswim46 Posts: 208 Member
    Also, 550 calories burned in 30 minutes of swimming? What were you doing to burn so much during a low impact workout?
  • lorrpb
    lorrpb Posts: 11,463 Member
    Sweat rate varies widely from one person to the next. I believe the best way to measure YOUR sweat rate is to weigh yourself immediately before and after your workout. However, it seems that you need an incredibly sensitive scale. I tried this a few times when running and did not get any change, despite having sweat a lot. I was interested it in mainly for hydration.
  • spiriteagle99
    spiriteagle99 Posts: 3,769 Member
    Drink when thirsty and keep track of your pee. If it's dark, drink more. That's really all you need to know about replacing sweat.
  • andysport1
    andysport1 Posts: 592 Member
    Joenali wrote: »
    Also, 550 calories burned in 30 minutes of swimming? What were you doing to burn so much during a low impact workout?

    I swim sets, I usually break into a sweat swimming, that day I was swimming 100metres on 1.45 so 10-15 seconds rest between x 15 plus a bit of a warm up.
  • andysport1
    andysport1 Posts: 592 Member
    lorrpb wrote: »
    Sweat rate varies widely from one person to the next. I believe the best way to measure YOUR sweat rate is to weigh yourself immediately before and after your workout. However, it seems that you need an incredibly sensitive scale. I tried this a few times when running and did not get any change, despite having sweat a lot. I was interested it in mainly for hydration.
    I've measured it this way twice now 3lb difference drank 500ml both times = a sweat rate of 2l/hour

  • Azdak
    Azdak Posts: 8,281 Member
    I pretty consistently lose 3.5-3.75 lbs per hour in water weight doing cardio. That's not all sweat--there is water vapor in your exhalations as well.

    In one research study in grad school a subject lost 7.5 lbs of water after getting legally drunk and sitting in a hot tub for 30 min.
  • andysport1
    andysport1 Posts: 592 Member
    Azdak wrote: »
    I pretty consistently lose 3.5-3.75 lbs per hour in water weight doing cardio. That's not all sweat--there is water vapor in your exhalations as well.

    In one research study in grad school a subject lost 7.5 lbs of water after getting legally drunk and sitting in a hot tub for 30 min.


    Wowser
  • sijomial
    sijomial Posts: 19,809 Member
    I've never tried to calculate sweat rate as it varies hugely for me from barely perspiring at all to a human fountain impression depending on the usual factors of heat/humidity/intensity but I do weigh myself before and after a long and/or hot bike ride to gauge my rehydration needs.

    In cool conditions a 750ml bottle is more than I need for a couple of hours riding, on a hot ride double the intake isn't enough to prevent dehydration.
    Moderate dehydration isn't as big an issue for performance as people used to assume.
  • stanmann571
    stanmann571 Posts: 5,727 Member
    rybo wrote: »
    Sometimes marathoners and other endurance athletes calculate a sweat rate. Pretty much you need to weigh yourself, exercise & reweigh. Preferably without drinking or eating anything. It's only a very rough estimate and can vary based on a whole host of factors.

    I understand the utility for endurance athletes who need to calculate rehydration rate/dehydration risks.

    But for normal people... I don't get it.
  • curlsintherack
    curlsintherack Posts: 465 Member
    chances are you just peed in the pool and forgot about it.
This discussion has been closed.

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