A motorized treadmill, known simply as a treadmill, is a piece of exercise equipment designed to increase cardiovascular efficiency while burning a relatively large number of calories. Found in health clubs, athletic training facilities, and cardiac rehabilitation centers as well as sold for in-home use, treadmills are intended for walking and running. They typically offer a variety of speeds and inclines, and many models feature built-in programs to train for a variety of goals, whether for fat-burning or for increased endurance. Because they provide exercisers with a more vigorous workout than many modes of cardiovascular exercise, as they require moving one’s entire body weight, they are popular as a method of calorie-burning.
While treadmills are said to have been invented in 1817 as a means of reforming prison inmates, it is unlikely that they were used for exercise until much later — at least not until after they were introduced into hospitals in the early 1950s as a tool for diagnosing cardiovascular disease, as they continue to be used today. A motorized treadmill is powered by electricity and operates via a motor, which moves a conveyor belt that encircles an oblong wheel or series of wheels known as flywheels. As the user propels himself forward, the motor moves the belt backward at the same speed. More sophisticated models may also feature an adjustable incline that can be raised up to 20 degrees, typically, in addition to computerized programs that require the user to jog or walk at varying speeds or inclines for predetermined intervals.
As with any form of exercise, there are advantages and disadvantages to treadmill usage. Relative to running outdoors on pavement, treadmills provide built-in shock absorption, which can reduce the risk of injury to the spine, hips, and knees. Walking on an incline, in particular, can greatly reduce the impact while also providing an increased challenge to the heart, lungs, and leg muscles. As a means of burning calories, the motorized treadmill is generally superior to other machines like the bike, stair climber, and elliptical trainer. It also gives exercisers an indoor option for walking and running, activities in which they might not be able to participate in extreme weather.
Disadvantages of treadmill exercise include the safety risk, as users can become injured as a result of falling or if the machine malfunctions. Walking or running on a treadmill, while posing less of a risk than doing so outdoors, is still a high-impact activity, so overtraining can lead to joint problems, especially in the knees, and can exacerbate existing problems. It is recommended to alternate days of treadmill use with days of lower impact cardio, such as riding a bike or using a cross-trainer like the elliptical machine. Finally, the practical implications of owning a motorized treadmill can be considered a disadvantage, as they can cost a lot of money to purchase and maintain, they require electricity to power, and they take up space in one’s home.