Sodium and Sweat

I was doing a good job of keeping my sodium intake near 2300mg. But then I realized I wasn't compensating for sweat?

I read that you lose about 585mg per pound of sweat. So I accurately measured my sweat after exercise at 2 lbs. And increased my sodium intake by 1170mg, making it about 3470mg per day.

I'm also using 2 servings of Ultima Replenisher Electrolyte Hydration Drink Mix before and after workout.

Does anyone have different numbers to go by?

Replies

  • Djproulx
    Djproulx Posts: 2,818 Member
    During normal daily life, including my usual weekday workouts of 60minutes or less, I don't worry too much about sodium/magnesium/potassium as separate intake elements to be measured. If it's hot, I'll sometimes use an electrolyte drink instead of water.

    That approach changes during longer sessions, typically on weekends. Since my swim, bike and run sessions can be long (eg 4-5 hrs for a bike/run combo) I'm very focused on both hydration and calories.

    I use Precision Hydration 1500 powder or tablets on the bike. I've taken their online sweat test/profile and follow their protocol especially during warm humid weeks. So a typical plan is to consume a 20oz water bottle w/PH1500 on Friday evening, then another bottle on Sat am before the long session. That way I have plenty of electrolytes in my system at the start, then 1 bottle/hr intra-workout. I'll then often consume one bottle of water and one more of electrolytes after a long ride/run.

    The goal is to replenish both fluids and electrolytes as quickly as possible during recovery to prepare for the next day's effort. The PH website has some good information on sweat rates, etc, if you are active in endurance training.
  • COGypsy
    COGypsy Posts: 795 Member
    I’m curious about “accurately measuring” sweat. How does that work? How do you account for evaporation? I’ve never heard of or thought about calculating sweat as a nutrition factor.
  • AnnPT77
    AnnPT77 Posts: 25,306 Member
    COGypsy wrote: »
    I’m curious about “accurately measuring” sweat. How does that work? How do you account for evaporation? I’ve never heard of or thought about calculating sweat as a nutrition factor.

    Weighing yourself before and after the workout is one option. In the calculation, include the weight of the water/fluid consumed between starting and ending weight.

    Sweat is a health and performance factor, for sure. I'm not sure if I'd think of it as a nutrition factor, but that's splitting rhetorical hairs.

    I'm not as structured as @Djproulx (who's IMO giving excellent technical advice here), but I do add electrolytes and of course manage hydration more thoughtfully during hot-conditions exercise, especially longer duration exercise (loosely, > 1 hour).
  • ninerbuff
    ninerbuff Posts: 46,336 Member
    Being Asian and not having any issues with high BP or hypertension, my intake is usually about 4000mg a day. And I don't sweat that much at all even on cardio bouts.
    So if you have no issue with either, sodium intake really only affects the amount of water you make retain.

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  • sijomial
    sijomial Posts: 19,775 Member
    COGypsy wrote: »
    I’m curious about “accurately measuring” sweat. How does that work? How do you account for evaporation? I’ve never heard of or thought about calculating sweat as a nutrition factor.

    That's a good point.
    Weighing before/after extended exercise sessions only really gives you a good guide to the amount of rehydration required and doesn't tell you how much was water vapour breathed out and how much was sweat.

    Personally I only feel the need to supplement with electrolytes for long (multi-hour) or hot weather exercise when it tends to be half my fluid intake has added electrolyte tablets.
    If I get it "wrong" I get clear salt cravings.
  • Lietchi
    Lietchi Posts: 4,283 Member
    I can't be bothered to measure my salt intake (that would require weighing the salt I use in my homecooked meals) and I have no intention of weighing myself before and after each exercise session. But even if I could, I'm pretty sure the amount of sodium expelled varies, just looking at the first source I found:
    "Sweat typically contains 40-60 mmol/L of sodium, leading to approximately 20-90 mmol of sodium lost in one exercise session". https://pubmed.ncbi.nlm.nih.gov/26841436/#:~:text=Sweat typically contains 40-60,associated with substantial health benefits.
    I'm a perfectionist in my logging, but this definitely seems like an impossible calculation to get sodium 'perfect' :smile:

    I'm an intuitive/'common sense' electrolyte user. I have naturally low blood pressure. When I'm low on sodium, I start getting dizzy/blacking out when I stand up. Since I've started using electrolyte tablets on days when I run (half a tablet for shorter runs) I haven't had this issue, so that seems to work for me.
  • autotech44
    autotech44 Posts: 14 Member
    I was getting the dizziness standing up. That's why I was looking into electrolytes. I guess an hour run isn't considered endurance training, but I do sweat out 2lbs per hour. I think that on top of my diet keeping sodium at 2300mg, lots of water, low carbs, and I pee a lot, brought my sodium level down too low. And even with my increase I'm still near most people's average.
  • Djproulx
    Djproulx Posts: 2,818 Member
    autotech44 wrote: »
    I was getting the dizziness standing up. That's why I was looking into electrolytes. I guess an hour run isn't considered endurance training, but I do sweat out 2lbs per hour. I think that on top of my diet keeping sodium at 2300mg, lots of water, low carbs, and I pee a lot, brought my sodium level down too low. And even with my increase I'm still near most people's average.

    Yeah, given your description, I think you'll feel better by including sodium/electrolytes in the mix. If you're like me, you can produce a lot of sweat in an hour, especially during warm weather runs. I'll often notice that my eyes start to sting from salty sweat and/or I have cravings for salty foods.

    Of course, the structured approach becomes more helpful or necessary in situations such as @sijomial describes.
  • cwolfman13
    cwolfman13 Posts: 41,016 Member
    I've never measured anything, but when I was trying low sodium I was frequently cramping up during and after exercise, particularly in the summer. My shirts were often caked with salt from sweat. I'm hypertensive so I was trying to lower my sodium, but it didn't seem to be making much difference anyway. I went to see my Dr. about the cramping issues as well as just not feeling all that great and he told me to up my sodium, just not go overboard with it. I don't remember the exact range I came out to, but the cramping stopped and I felt a lot better...I think I was in the 3000 range or so. I also just kind of let my salt cravings be my guide...I'm actually not big on salt so it seemed to me that if I was craving it, there must be a reason.
  • autotech44
    autotech44 Posts: 14 Member
    edited June 23
    Djproulx wrote: »
    Yeah, given your description, I think you'll feel better by including sodium/electrolytes in the mix. If you're like me, you can produce a lot of sweat in an hour, especially during warm weather runs. I'll often notice that my eyes start to sting from salty sweat and/or I have cravings for salty foods.

    Of course, the structured approach becomes more helpful or necessary in situations such as @sijomial describes.

    I always get the burning eyes and salt rings on my shirt and hat. And I'm sweating significantly more since I upped the sodium.

    I discovered a good quick salt fix. Pimento stuffed olives. 230mg/20 calories each.

  • Djproulx
    Djproulx Posts: 2,818 Member
    autotech44 wrote: »
    Djproulx wrote: »
    Yeah, given your description, I think you'll feel better by including sodium/electrolytes in the mix. If you're like me, you can produce a lot of sweat in an hour, especially during warm weather runs. I'll often notice that my eyes start to sting from salty sweat and/or I have cravings for salty foods.

    Of course, the structured approach becomes more helpful or necessary in situations such as @sijomial describes.

    I always get the burning eyes and salt rings on my shirt and hat. And I'm sweating significantly more since I upped the sodium.

    I discovered a good quick salt fix. Pimento stuffed olives. 230mg/20 calories each.

    Those sound great. (Now I'm getting hungry).

    A few of us carry the fast food restaurant salt packets in our run vests as a backup to our liquid sodium sources. Salted pretzels, chicken broth and pickle juice are the most popular options on the run courses at many triathlons.
  • westrich20940
    westrich20940 Posts: 537 Member
    autotech44 wrote: »
    I was getting the dizziness standing up. That's why I was looking into electrolytes. I guess an hour run isn't considered endurance training, but I do sweat out 2lbs per hour. I think that on top of my diet keeping sodium at 2300mg, lots of water, low carbs, and I pee a lot, brought my sodium level down too low. And even with my increase I'm still near most people's average.

    If you're running for an hour outside and it's hot...I'm sure there's no problem with supplementing your electrolytes.

    My long runs are ~1.5hrs and I'm lucky that in most of the summer I can just get up in the morning and do it before it's like...hot hot. However, even if it's only 73F where I live it is still quite humid in the summer and I sweat a lot, and am a salty sweater (like once my sweat dries on my face I can rub all the salt off, ewww). So I def supplement for sure on days I do a long run outside or a long hike outside. I use Nuun tablets and will just throw like 2 in my water after my run or in my water bottle on my hike --- and that, plus just constantly having a cup or bottle of water helps me make sure to stay hydrated.

    As far as paying attention to the sodium content specifically of what I eat - I don't bc I don't have any medical reason to as far as I know or my doc has told me.