Treadmills
Treadmills are the most popular form of home exercise these days. They’re easy to use, versatile (in that they can be used by people of varying fitness levels), and can be combined with hand weights to incorporate an arm workout.
Treadmills can always prove to be a challenge, as you can adjust the speed and incline to increase the intensity of the workout. As is it a weight bearing exercise, it can also help prevent osteoporosis.