Presenter Davina McCall left a number of her fans well and truly baffled after telling them about her latest bizarrely named hobby.
The Long Lost Family host, 52, posted a snap of her washboard abs on Instagram and revealed she had just done "a bit of fartlek".
While she didn't explain what the activity entailed, Davina said it kept running "interesting" and admitted the odd name "still makes her giggle".
She captioned a photo of herself in her gym gear, toned stomach on full display: "Just back from a bit of fartlek (still makes me giggle) training. It keeps running interesting... about to do abs and arms."
Understandably, many of her followers on the social media site appeared to have no idea what this mysterious form of training might be.
Still makes me giggle.
One baffled fan asked her: "Fartleck??? You look amazing."
Another user commented, alongside a confused-face emoji: "What's a fartlek?"
A third said: "I'm intrigued, what is #fartlek?"
Someone who was in the know said: "Yes! Love fartlek running! First time I did it, I kept laughing at the name X."
Fartlek, Swedish for 'speed play', is a form of exercise that mixes continuous and interval training.
In short, a fartlek run is one that switches up periods of fast running with slow running.
According to Runner's World UK: "Fartlek is unstructured and alternates between moderate to hard efforts with easy efforts throughout.
"After a warm-up, you play with speed by running at faster efforts for short periods of time (to that tree, to the sign) followed by easy-effort running to recover."
Davina's love of exercise and keeping herself in shape is well known to her followers on Instagram. The former Big Brother presenter isn't shy when it comes to showing off her toned physique and sharing fitness tips with her fan base.
Earlier this year, she stunned with a bikini photo to show off her rock-hard abs and told fans: "Shameless bikini selfie. End of."
Leave us a comment on our Facebook page @EntertainmentDailyFix and let us know what you think of this story.