Treadmills were originally created for use in prisons as a way to harness the power of the prisoners’ steps to accomplish tasks – usually grinding grain or pumping water. The first prototype was invented by William Cubitt and installed at Surrey House of Correction. Thankfully, the treadmill as a method of hard labor in prisons died out in the early 1900s. But the machine didn’t disappear. Concerned about the rising number of deaths caused by heart disease, Dr. Robert Bruce added a motor to a treadmill in the late 1940s and began using it to test patients for heart problems. In the 1960s, Dr. Kenneth Cooper announced that regular exercise could help prevent heart attacks, kicking off the aerobics movement. Then Bill Staub, a runner and mechanical engineer, created a treadmill for home use to help people reach their exercise goals despite inclement weather; it was called the PaceMaster. From then on, treadmills became synonymous with fitness and today they are found in many homes and gyms across the world.