So this is weird. If I exercise hard (with my current fitness that means a rather hilly 30k ride with not enough food on Sunday morning) I feel fine (well, my legs were dead, but apart from that) until the next day, when I typically wake up with an almost full body rash. Sweat rash, probably. It’s also warm to the touch, and over the course of Monday it got darker and warmer until at 10pm I was wearing several layers and my entire body was shivering… Today it’s fading but it’s still there and I’m still shivery.

This isn’t usual right? Pretty sure I can’t make it go away as I’ve had this for several years, although typically it’s just the rash and not the shivers. Someone else say that they have this so I’m not a lone medical freak!

You’re allergic to exercise.

That, or cat aids (the bad kind).

NOT CAT AIDS!

When I used to run a lot in my teens I would occasionally come out in an blotchy, really itchy rash over my whole body after a really hard run. Never got the shivers with it though.
It used to start perhaps 5-10 mins after finishing, usually while I was in the shower & an anti-histamine would have it gone in a hour or two.

I never got to the bottom of what caused it – it was so infrequent, that it didn’t seem worth speaking to anyone about (maybe 3x a yr) and I think I just grew out of it.

I get it from Stella Artois

Prickly Heat I reckon.

I get it sometimes.

What are you wearing? If you think it’s a sweat rash, it could be because of the detergent you use to wash your kit?

Ive had some of the fevers at night after a long day on the bike (waking up drenched in sweat and shivering with cold). Had some blood tests done but never got to the bottom of it. In the end I decided that it was possibly a lack of protein/ calorie deficit (you mentioned not eating enough) after a lot of exercise (only eating 500-1000 calories after burning 2000-3000) and took it as an excuse to eat lots more. Haven’t had them for a few years now.

Wearing a merino base layer, poly long sleeved jersey, and then a shell. Temperature averaged 6C and showery, didn’t feel like I was boiling or cold.

Detergent is the same stuff we always use.

I definitely didn’t eat enough: just a bowl of cornflakes at 8am before what Strava guesses was 1400kcal of effort (forgot the HRM as well as the banana so that’s not massively accurate).

Excercise? God no. Did I not mention I have an Ebike for that?

Missus sometimes breakouts into hives when she works out, initially I made the mistake of ribbing her (not a good idea)turns out it does affect some people. It goes away pretty fast though.

Look up Cholinergic Urticaria

I get it from Stella Artois

I thought I was the only one!

When I picked up exercising more and playing squash I would occasionally come out in an itchy rash on my upper body. The more I played and did exercise it stopped, never sure why and it now doesnt occur.

Detergent is the same stuff we always use.

That doesn’t mean it isn’t causing it though.

Maybe it’s something you have eaten that resides in your sweat.

Probably exercise induced hives. its quite common. I get it from tiredness which is bloody annoying.
It ranges from hives on the fingers to a full-on outbreak all over the body.

When i first got it i thought i was allergic to something in some cocktail sausages that I’d eaten copious amounts of the night before. I was relieved when it wasn’t that. although I did avoid them for about a year before i realised.

cetirizine (hayfever one a day – don’t get the branded stuff) generally sorts it after about 20 (uncomfortable) minutes. Sometimes, it doesn’t work if I don’t catch it early enough. Then I just have to get some sleep.

I get this when I run. I have an anti histamine an hour before exercise and it helps stop the reaction.