Does anyone know how to reduce one's sweat rate? Currently I lose about 3lbs of sweat an hour when I run, even on mild days where the temp. is around 60-70 degrees. As I'm training for ultras, I'd like to reduce that rate if possible. I believe I can take electrolyte pills, but unaware how effective they are and how they impact sweat rate.

UPDATE: Someone mentioned that electrolyte tablets can reduce the amount of sweat you lose during exercise. Is this true or do those only help you keep your sodium levels up?

  • 1
    How did you measure 3 lbs per hour of sweat loss? Just curious.
    – Matt Chan
    Jun 26, 2012 at 14:57
  • @MattChan Weigh yourself dry before you start. Track drinking (and avoid peeing if you can). weigh yourself at the end and do the math.
    – geoffc
    Jun 26, 2012 at 18:16
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    Electrolyte tablets will not change your sweat rate. All they do is help replace electrolytes. Your sweat rate is your sweat rate, and that's controlled by your body.
    – JohnP
    Jun 30, 2012 at 0:29

4 Answers 4


I do not think you can do anything specific to control sweat rate, rather you can learn to deal with it.

Having trained for Ironman, I know what you are talking about. The logistics of the amount of water and salt on long training days gets ridiculous. My first Ironman, I drank 18 litres on the bike, and 8 litres on the run (it was a hot day) and I still lost 9 lbs. That is like 50+ lbs of water sweat out.

The electrolytes matter as each litre of sweat can contain 1-1.5g of salt. That is a LOT of salt to recover.

As you get more fit and your body accommodates to the hot weather through training in it, your sweat should get a little more dilute which helps.


Sweat rate is sweat rate, you can't really control it. Your best bet is to experiment with different fluid and electrolyte replacement modes in training, and see what works best for you. I'm in the same boat, on a 4 hour bike ride (in Phoenix in the summer), I drink close to 80 oz an hour and still lose 4-5 lbs of weight.

One thing to remember, is that it's not only water, but when you work out, you are also using up glycogen stores which accounts for some of the weight loss as well. In addition to fluid replacement, you also want to think about calorie replacement. Endurance athletes such as long distance triathletes aim for anywhere from 250-400 calories per hour in various forms (Gu, Nuun, etc.)

Work with it in practice and training, try to replicate what your race conditions will be, and find what works best for you. Unfortunately, there is no magic formula that will apply.


I feel your pain - I absolutely pour with sweat with any vigorous exercise, even in cool conditions. The conclusion I have to draw is that I'm dumping a lot of waste heat, and the profuse sweating is meant to get rid of it. I've also noticed that my sweat has an extremely strong smell of ammonia, so much so it's made me cough in the past.

Could be that people who sweat a lot are less efficient at liberating energy from their stored reserves and as a result dump more heat - and there probably isn't anything you can do about that, unless under the direction of an expert exercise physiologist.

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    Ammonia is generally from a high protein low carb diet. When you exercise, and amino's are broken down you get waste products such as ammonia, etc. If it's too much for the body to break down into urea for excretion, it will get dumped with sweat. It can also be a sign of dehydration.
    – JohnP
    Jul 2, 2012 at 21:52
  • That's probably pretty accurate - I really enjoy protein-rich foods, particularly red meat and cheese. At the time of writing I was typically having two 'meat and two veg' type meals per day. My diet hasn't presented a problem for me in terms of weight gain or obvious ill-health, apart from the issue I noticed here. As of December 2013 having gotten considerably fitter and changed my diet, the sweating problem has diminished somewhat.
    – Tom W
    Dec 30, 2013 at 0:19

A high sweat rate is a good thing, actually. To cool your body during exercise, your body will sweat and it will also circulate blood to the skin. If you sweat more, your body can cool itself better, thus less blood has to be diverted for cooling purposes. You want that precious iron rich blood going to your muscles rather than your skin for cooling.

Yes, you can control your sweat rate. When you train in the heat, your body will adapt in a process called heat acclimatization. Your sweat rate will increase, but your sodium concentration in your sweat will decrease. Heat acclimatization has performance benefits in hot weather, but also cold weather as well. Elite runners will do easy runs in sweat suits to stay heat acclimatized. You could do the opposite to decrease your sweat rate, but why would you want to. So be encouraged by a high sweat rate and just remember to stay hydrated.

  • "Elite runners will do easy runs in sweat suits to stay heat acclimatized" - this is not true. Or if it is I'd like to know who does this and how well it worked. I know a lot of elite runners (several at the olympic level) and it issomething none of them do.
    – ngramsky
    May 13, 2015 at 18:00
  • Here is an article by Alan Culpepper that discusses it. The takeaway is heat acclimatization will improve performance regardless of temperature. Your elite friends should at least consider training in the heat a few days a month. Especially if they live in a place prone to hot and humid weather like NOVA. runnersworld.co.uk/staying-healthy/running-in-the-heat/… May 17, 2015 at 3:50

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