The GP broke down the science behind your post-workout flush and whether there's anything you can do to prevent it
News Amber O'Connor Money and Lifestyle reporter U35s 04:00, 18 Apr 2025
Most of us have been there. You've just finished a gym class, or perhaps you've just returned home from a run, only to look in the mirror and realise you're bright red. It's enough to make you blush.
However, you'll hopefully be reassured to know it's normal to go red following exercise. Dr Donald Grant, GP and Senior Clinical Advisor at The Independent Pharmacy, says: "This phenomenon is known as ‘flushing’ or ‘blushing’ and occurs due to increased blood flow and heart rate."
He explains: "During exercise, our body temperature rises, leading to blood vessels dilating as the body tries to cool itself down. The increased blood flow can give people a reddish appearance and is a completely natural reaction following exercise."
It's true that some people might not look as flushed as others. Dr Grant says: "A combination of factors can influence how red people turn following exercise. Firstly, genetically, some people have more blood vessels that dilate easily in comparison to others, quickly giving them a redder appearance.
"Furthermore, people who suffer from rosacea might experience more intense flushing than others. People with rosacea tend to have more sensitive blood vessels, leading to a very red appearance following exercise. Other contributing factors include skin colour, exercise intensity and the environment’s temperature."
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For the most part, the redness should subside almost as quickly as it arrived. “Typically, it takes around 30 minutes to an hour for this physiological response to subside. However, some factors can prolong this reaction, including how warm it is and the intensity of the workout.
"For example, people who exercised intensely in hot conditions could expect the redness to remain for longer than usual, however, this very rarely exceeds two hours," says the pro.
Some types of exercise might also cause more redness than others. Dr Grant gives cardio exercises such as running, cycling, and swimming as examples. He adds that a sauna session or hot yoga class could also lead to more intense flushing because it increases the body's natural temperature.
While flushing could cause embarrassment for some, Dr Grant thinks it's something to be celebrated. "The most important thing to keep in mind is that this reaction is completely natural. Going red after exercise is actually a good thing and means that people have engaged in a sufficient workout that pushed their limits.
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"Anyone who feels self-conscious about flushing should come prepared - be sure to take a cold water bottle and cool compress, and don’t be afraid to speak up if exercising in a group."
As for whether it's something you can prevent, Dr Grant had this to say: “As flushing is a natural physiological reaction, it can be difficult to prevent. However, people can reduce the likelihood of experiencing this by avoiding exercising during the hottest periods of the day, opting for a morning or late evening workout instead.
“Furthermore, it’s important to hydrate, as this plays a massive role in regulating our body temperature. Keeping a cold towel on hand can provide a cool compress in between workouts, allowing people to reduce their redness by quickly returning to a natural temperature."
