There are a number of culprits, right here. First up: Whenever you train, your coronary heart pumps extra blood to your laborious working muscle mass. This momentum then causes your capillaries to expand, and as they achieve this, they stimulate the encircling nerve cells in your physique—and your mind interprets that sign as an itch. “This can be a extra doubtless state of affairs for the physique versus the face,” says board-certified dermatologist Deanne Mraz Robinson, M.D., FAAD, co-founder of Modern Dermatology and assistant medical professor of dermatology at Yale New Haven Hospital, (since your bigger muscle teams are powering the toughest, and thus require extra blood movement), “However the identical science applies.” 

Or, for those who’re vulnerable to flushing while working out, itch can definitely comply with. “Train results in dilation of your blood vessels to boost circulation to your pores and skin and muscle mass,” says board-certified dermatologist Joshua Zeichner, M.D. That is typically a superb factor—in spite of everything, it’s elevated circulation that delivers vitamins to the cells and lends the beloved “post-workout glow.” However for some folks (particularly these with truthful to medium pores and skin tones, delicate pores and skin, or situations like rosacea), it will possibly result in irritation, which may end up in flushing, bumps, and, sure, itching.

In some instances, that prickly sensation may also signify a sort of warmth rash, known as miliaria rubra. “This can be a situation the place there are blockages inside the sweat glands, resulting in tiny, pink bumps and a prickly or itchy feeling,” says Zeichner. “This develops when sweat is trapped within the glands due to points like non-breathable, moist exercise clothes sticking to the pores and skin.” It’s additionally far more widespread in sizzling, humid climate—say, for those who’re jogging outdoors noon within the throes of summer time. 

And, lastly, folks can simply react to their very own sweat. Whereas sweat can effectively clear pores, some people could also be hypersensitive to its contents. “Moisture, warmth, and sweat can all trigger irritation of the pores and skin,” says Mraz Robinson. Easy as that.