Reduce sweat rate?

Question

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?

Answer 1

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.

Answer 2

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.

Answer 3

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.

Answer 4

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.