A school has introduced pedal machines under its desks in a bid to tackle the "rise in obesity and type 2 diabetes".
Thirty machines, costing £20 each, have been bought using the PE budget for pupils at Red Oak Primary in Lowestoft, Suffolk.
Head teacher Heather Madsen said: "This is about setting up activity levels for the rest of their lives."
She hopes to fund more machines across the 430-pupil school, as first reported in the East Anglian Daily Times.
Their use is not compulsory, but the head teacher said pupils have welcomed them.
"It was initially a novelty and like the Tour de France here, but since then they've calmed down and some are doing it out of habit," she said.
"We were talking about initiatives that would stimulate the children's concentration and ensure they could still stay focused on lessons."
The machines, which were introduced this term, feature a display that shows duration of pedalling, number of revolutions per minute and calorie consumption - with some pupils burning up to 800 calories a day.
Evie-Rose, a pupil at the school, said: "I enjoy it because it's really fun, your brain works faster and you get stronger and smarter at the same time."
Another pupil, Ella, said: "Sometimes we try to beat each other in class. I feel really famous because we've had lots of visitors wanting to put us on their news."