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You may think that caged mice race around their exercise wheels out of sheer boredom, having been driven mad by their captivity.

But a new study suggests that the rodents enjoy running and when wild mice come across an exercise wheel they do exactly the same thing voluntarily.

A group of scientists set up wheels in the wild to see if the activity is 'natural' and found that not only mice took to the gym apparatus for a quick jog, but frogs hopped on too.

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On a road to nowhere: For a long time it has been suggested that captive mice use exercise wheels in their cage out of boredom, but now scinetists ahve found that wild mice voluntarily use the machines for exercise, proving that the action is 'natural' and not neurotic

Over the years lots of scientific studies have relied on mice running on wheels to test the effect of exercise on health, but some experts were worried that wheel running is not natural and therefore not useful as a stand-in for human exercise.

However, this study, by Leiden University Medical Centre in the Netherlands, suggests that while fixed wheels are not often found in the wild, the activity of running on them seems to be natural.

The research dispels the idea that wheel running is the result of captivity and arguably the behaviour of neurotic animals kept in boring and arguably poor conditions.

To come up with the findings, scientists Johanna Meijer and Yuri Robbers put running wheels in open cages in quiet 'green urban areas' so that small animals could enter the makeshift gym and leave again easily, the study published in the Proceedings of the Royal Society B said.

Food was left to attract wildfire, but was not a reward for exercising. A motion sensor activated camera equipped with night vision captured the creatures running to nowhere, Science News reported.

Cool runnings: The scientists placed running wheels in open cages (pictured) in quiet 'green urban areas' so that small animals could enter the makeshift gym and leave again easily

Over 200,000 recordings at two sites were captured over a period of three years and 12,000 videos analysed. Among the gym-going wild mice were rats, shrews, frogs and even a slug attempting a slow ride on the wheel.

While the scientists observed that some animals started running on the wheel unintentionally, others hopped off then got back on again and began to run, indicating that their exercise session was intentional and enjoyable.

Typically the wild mice ran for stints of up to a minute, but one in five worked out for longer, with one sprinting for 18 minutes.

For the final year the experiment was running, the researchers stopped leaving food to entice mice to their playground and discovered that lots of the mice kept turning up as before – although some gave up their exercise regime.

The scientists are not sure why mice voluntarily run on wheels to no advantageous end.

They wheel-y love it: Over 200,000 recordings at two sites were captured over a period of three years and 12,000 videos analysed. Among the gym-going wild mice (pictured b) were rats, shrews, frogs (pictured c) and even slugs (pictured d) attempting a slow ride on the wheel. Mice accounted for 88 per cent of the wheel use