Ten-month-old Utrecht hamster Mollie logs nearly 70 km a week on fitness app Strava

A 10-month-old hamster named Mollie routinely covers nearly 70 kilometers a week on her exercise wheel. Her owner, physicist Thijs de Buck, engineered a system that automatically uploads the nightly data to the fitness app Strava. Mollie's personal best so far is 11.15 kilometers in a single night.

The Utrecht hamster’s consistency and volume have drawn comparisons to serious endurance athletes, AD reports. Mollie averages nearly 10 kilometers per night, with bursts reaching 5 kilometers per hour. De Buck said the distances reflect normal, healthy behavior for hamsters. In the wild, the small animals travel long distances at night in search of food.

The project began with simple curiosity, De Buck said. He wanted to know how far his hamster ran overnight. Now Mollie has a Premium account and generates responses on the app such as "The Fast and the Furriest.”

A low-cost bike computer mounted on the wheel failed because it powered down whenever Mollie paused for more than five minutes. “If Mollie took a lunch break at 1 a.m., we had no idea how much he ran after that,” De Buck told Runner’s World.

He then replaced it with a custom setup using a magnet and sensor on the wheel. A small computer records every revolution and transmits the data to Strava each morning. De Buck’s only task is to add her photo on the app. “Mollie does the real work at night,” he joked.

Automatic uploads required a paid subscription. “So there was only one solution: my hamster now has Strava Premium,” De Buck said.

“I trained for about half a year for a marathon and got maybe forty kudos," De Buck told the Canadian broadcaster CBC. “Mollie gets about a thousand every night. It’s not fair. My hamster beats me.”