Manual treadmills are generally simple in design and very affordable. The belt on the treadmill moves by virtue of your foot pressure while walking.
Some manuals have adjustable incline (also manual), a highly desirable feature, since increasing the incline allows you to vary the intensity of the workout. You can set your own pace on a manual – it goes only as fast as you go. Some people think using a manual is boring because of its limited functionality. Whether manual or powered, your treadmill should have a digital display that shows minimally how fast you’re walking and how far you’ve gone. If you stick with your exercise program, chances are you’ll outgrow a manual treadmill rather quickly as your endurance increases. For example, you can’t run on a lot of manual treadmills. They aren’t designed to take the stress.
Powered treadmills use a motor to move the belt, keeping the rate at which you walk constant – you go as fast as the machine. Many powered treadmills have powered incline adjustment. Electronic displays on this type of treadmill are more elaborate – showing a variety of information including calories burned. One of the main advantages of a powered treadmill is that it’s more challenging – it can go faster than you can, so you have to work harder to keep up. Some powereds have built-in programs that vary the intensity of the workout automatically, a feature that helps keep the workout from getting boring. One of the drawbacks of a treadmill is that it’s high-impact. Some treadmills have a mechanism (like moving pole handgrips) that will also exercise the arms and upper body.
Elliptical trainers offer the same benefits as a treadmill but are low impact machines, i.e., your feet stay stationary. These machines have adjustable resistance; sophisticated digital displays and are quiet in operation. Ellipticals use a flywheel and have a roughly circular motion (ellipse) that takes a little getting used to. Some models offer reverse motion as well as forward. The better machines have a fluid, natural motion and also exercise the arms and upper body.
Exercise bikes, recumbent bikes and pedal exercisers are good for the large muscle groups in the legs. The popular spinning workout is done on an exercise bike. These machines are manual and have variable resistance. Some exercise bikes will also work the torso and upper body. A recumbent bike puts less pressure and stress on the back, since the pedaling motion is accomplished from a reclined position. A small, compact device, the pedal exerciser is good for people who can’t sit on a normal exercise bike because it can be used while sitting in a chair. The pedal exerciser can also be placed on a table to exercise the arms.
Rowing machines have the advantage of using the entire body in a single, fluid motion. The seat on a rower slides on rails and there are handles attached to stretchy cords that simulate the arm motion of using a paddle. When performed with the correct technique, rowing spreads the intensity of exercise evenly over all three major muscle groups, legs, arms and torso. Rowing is low impact and non-load bearing. Rowers are manual devices.
Ski machines are similar to rowers, in that they exercise the major muscle groups in a single fluid motion that simulates cross country skiing. The “skis” on these machines travel back and forth with leg motion. There are elastic cords to simulate the arm action of using ski poles. Offering another low impact workout, ski machines are also manual.
Stair steppers are tried-and-true aerobic exercisers that focus on the large muscles in the legs. Simple in design and low impact, steppers are compact have adjustable resistance to increase as your strength and endurance increases. A better stair stepper will have hydraulic cylinders for smooth motion. Some steppers have moveable handgrips for working the upper body. New generation “tread climbers” add the benefit of walking on a treadmill to the simple stepping motion.