I've had a couple running events recently that have been pushing my endurance (a competitive half marathon, and running 20+ trail miles for a fun-run). The night following these events I've woken with night sweats--sweating profusely in my sleep (yes, it's definately sweat).

Internet searches turn up different mentions of it and supposed explanations. I'm curious if there's any objective information about whether it's a common side-effect of hard training, or if it's indicative of either going too hard or doing something incorrect (e.g. some claim it's a side-effect of taking in too much salt).

  • Do you mean the night before, or after? Nov 12, 2012 at 20:36
  • Hi Dave, it's been the night after the event. So run 20 miles, go to bed, wake up drenched in sweat.
    – STW
    Nov 12, 2012 at 20:40
  • Huh; never experienced anything like that. Interesting. Nov 12, 2012 at 20:41
  • jap.physiology.org/content/79/5/1434.short might point in the direction of an answer
    – FredrikD
    Nov 13, 2012 at 12:35
  • Just finished a marathon on Sunday. My estimated cal burn was 3900. I drenched both side of the Airbnb bed I’d hired for the event. It was gross. It has happened every time I’ve ran a Marathon or long runs leading up to one. The best thing I’ve found sleeping under breathable fabrics (Pendelton blanket) with a fan on in the open window helps.
    – DrP
    Jan 23, 2019 at 6:12

3 Answers 3


I train for cycling time trials, ranging from 10 mile sprints to 12 hr endurance races. I train on Heart rate and power meters, so I know accurately when I've upped my endurance/fitness. I find if I have a training session, whether that be Turbo or out on the road and I've exceeded a burn of 3000 cals then that following night (without fail) I will suffer with drenching night sweats, to the point I Have to to have a bath towel under the sheet to aid in not ruining my mattress.

I've had blood tests to check for anything sinister and all came back clear, It's the increase in training that causes my drenching night sweats. The second night the night sweats seem to be halved, then the following night is usually all clear until I push my training regime once again. Hope this helps.


Night sweats can be related to an increase in exercise intensity due to the affect of exercise on the endocrine glands and hormone secreations. In general, excessive sweating at night is caused by hormones. That is why menopausal women are prone to night sweats.

However, there are also several other causes, including medical or medication causes so night sweats may warrant a medical checkup in some cases.

If you want objective information regarding the affect of increasing exercise intensity on the thyroid, see Neuroendocrinology Letters: Exercise Intensity and Its Effects on Thyroid Hormones referenced in this Livestrong article: Increased Exercise and Night Sweats


In 2013 I resumed playing AFL football at the age of 32 in Perth WA. After not playing any sport for 13 years.

My symptoms occurred after medium to heavy exercise (Football Training in the evening 6-7.30pm) or late afternoon games on the weekend. Once my body starts to cool down it seems to lose control of its ability to regulate it temperature and I begin to shiver fairly intensely (Mostly when in a cool environment like in winter). I can stop the shivering by putting some warm clothes on and a doona if going to bed. But shortly after falling asleep I wake up drenched from head to toe in sweat.

My family and I lived in Darwin NT (Tropical Environment) for 3 years and played footbal during this time. I rarely had the shivering occur due to Darwin always being hot. But the sweating did occur and I would have to change my shirt up to 2 times a night. (Again after football training 6-7.30pm) and even in an environment where I could control the temperature via the air conditioner.

We are now back on Perth and after my first game last weekend I woke up that night about 3 times absolutely drenched. Clothes and bedding. The following night I continued to sweat (even after no exercise that day) but no where near as bad as the first night.

Had blood work done and everything normal

I read a lot of similararities online and interested to see if anyone had found the cause to this issue or any trials that have been performed?

Regards Nick

  • Welcome to the site! I'd invite you to take the tour and read the help section as we aren't really a discussion site, we expect concrete answers. As to why it is happening to you, that is really something you should discuss with your personal or team doctors.
    – JohnP
    Apr 8, 2019 at 13:45

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