© Shutterstock

19th-century origins -

To anyone who has experienced the endless monotony of walking or running on a treadmill, it will come as little surprise that the device was originally used as a prison torture device!

© Getty Images

19th-century origins - The treadmill was first devised in 1818 by the English inventor William Cubitt. At this time, English prisons were known for their poor conditions and inhumane punishment methods.

© Getty Images

Pre-reformation prisons - The most common methods of punishment included execution and deportation. Those who were lucky enough to remain in the prisons were confined to tiny cells.

© Getty Images

Pre-reformation prisons -

Religious groups, philanthropists, and influential figures such as Charles Dickens sought to do away with such dismal conditions and campaigned for a more reformative prison system.

© Getty Images

A more humane punishment - The treadmill was invented and adopted as a more human method of punishment. Groups of prisoners would walk on a large wheel with 24 spokes, sometimes for up to eight hours a day.

© Getty Images

Dual purpose - The idea was that being subjected to hard labor would aid the inmates' rehabilitation. There was also the added benefit that the treadmill would pump water or grind corn.

© Getty Images

Dual purpose - Sometimes the treadmill would also power windmills, hence the device's name. Originally it was called a "tread-wheel," but its use for powering windmills made "treadmill" more fitting.

© Getty Images

Torture - Although more humane than execution, as a punishment the treadmill was nonetheless very gruelling. It is estimated that the average prisoner spent six hours a day on the machine.

© Getty Images

Torture -

Oscar Wilde wrote of his treadmill experience in a poem: “We banged the tins, and bawled the hymns, /And sweated on the mill: /But in the heart of every man /Terror was lying still.”

© Getty Images

A global trend - The treadmill became increasingly popular in English prisons and its use as a punishment method quickly spread across the British Empire and to America.

© Getty Images

A global trend - In 1824, New York prison guard James Hardie claimed that the device had helped him whip the prisoners into line, citing the effectiveness of its “monotonous steadiness.”

© Getty Images

The end of treadmills in prisons -

Treadmills in prisons only lasted until the end of the 19th century. In England, they were banned for being “excessively cruel” under the Prison Act (1898).

© Getty Images

The comeback - The treadmill made a comeback, of course, and its resurgence was all thanks to the rise of heart disease amongst American citizens at the beginning of the 20th century.

© Getty Images

Medical use - By 1910, heart disease had beaten tuberculosis, pneumonia, and influenza to the top spot in the list of illnesses killing the highest number of North Americans.

© Getty Images

Medical use - Doctors trying to work out how to reduce the number of deaths by heart disease soon realized they needed a way to slowly raise a patient’s heartbeat, so as to detect irregularities.

© Getty Images

Dr. Robert Bruce - In the late 1940s, a certain Dr. Robert Bruce attached an adjustable motor to a treadmill-like “dog-exercising device” that had been patented by John Richards in 1939.

© Shutterstock

Dr. Robert Bruce - By hooking up patients to an ECG and walking them on the treadmill, Bruce could detect irregularities in heart rhythms. This protocol forms the basis of today's cardiac stress tests.

© Shutterstock

Dr. Kenneth Cooper - Another doctor to use the treadmill was Dr. Kenneth Cooper, an ex-Army and Air Force physician who used them to test for heart problems in patients at his Dallas clinic.

© Getty Images

The running craze - Dr. Cooper also believed in exercise that raised the heart rate as a great way to stave off illness. In 1968, he published an exercise book, ‘Aerobics,’ which focused on running.

© Getty Images

The running craze -

Running became hugely popular in the 1970s, partly thanks to Dr. Cooper’s book and partly due to a number of famous athletes who made running seem cool.

© Getty Images

Steve Prefontaine - An example of one such athlete is Steve Prefontaine, whose cult following of runners grew rapidly after he died in a tragic car accident in 1975.

© Getty Images

Bill Staub - One particular individual who became obsessed with running was mechanical engineer Bill Staub, who was eager to achieve Cooper’s (pictured) much-coveted eight-minute mile.

© Getty Images

The birth of the PaceMaster -

But during his training, Staub became frustrated at the fact that running during the winter was so difficult. At the time, indoor treadmills did not really exist outside of medical exam rooms.

© Shutterstock

The birth of the PaceMaster - And even the ones that did exist for medical purposes were bulky, expensive, and not really intended or suitable for common, everyday use.

© Shutterstock

The birth of the PaceMaster -

So Staub set about creating a treadmill that could go in a home (gyms were not really prevalent at this time), and thus the PaceMaster was born.

© Getty Images

The modern treadmill -

By the time Staub’s company folded in 2010, it had sold tens of thousands of treadmills. Unfortunately that didn’t compete in what had become a fairly crowded market.

© Shutterstock

The modern treadmill -

With the treadmill being by far the most popular exercise machine in both home and commercial gyms, huge numbers of them are sold every year.

© Shutterstock

The modern treadmill -

According to the Sports and Fitness Industry Association, in 2017 home treadmill sales reached US$999.8 million and gym treadmill sales $348.9 million.

(TEDEd) (New York Times)

See also: The bizarre history of home fitness.

© Shutterstock