But you don’t have to be a runner to experience these feel-good effects, according to Edsor. He says spending a good chunk of time doing any physical activity you enjoy – from Pilates to weightlifting – can give the “same kind of emotional fulfilment and joy”.

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You might not feel like shouting from the rooftops after yoga, Edsor admits, but he says many studies have shown that people’s moods are “dramatically” improved after working out. In other words, don’t chase a runner’s high. Instead, simply being active on a regular basis is a great way to boost your mood.

But if you’re one of the lucky ones who is on cloud nine after a run, Lukins says you’re bound to reap the rewards. “From a psychological perspective, those who experience runner’s high report a lower perception of pain, enhanced mood, improved general wellbeing, lower levels of anxiety and, for some, a sense of euphoria.”

Muir can speak to all that. She says she pushes through because she knows just how brilliant she’ll feel when that high courses through her body. “It makes me feel invincible; like anything is possible.”

Evelyn Lewin is a GP and freelance writer.

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