The ProForm XP 550E and XP 550S are motorized treadmills designed for residential use. They both hit the market about 2005 and were sold through Sears department stores. There are few differences between the two treadmills. They have the same specifications and design. The only significant difference is in the preset workout program options.
The ProForm XP 550E and XP 550S are foldaway treadmills. Many ProForm treadmills have this same space-saving design. You can lift the deck to store the treadmill in a vertical position. The deck is 18 inches wide and 55 inches long. It features Pro Shox cushioning, which, according to the manufacturer, reduces impact to your joints by up to 22 percent.
All ProForm treadmills can handle user weights up to 300 pounds. The XP 550E and XP 550S have a 2.75-horsepower motor. ProForm recommends that if you are over 225 pounds, you should look for a treadmill with at least a 3.0-horsepower motor. Both treadmills have a speed range of 0 to 10 mph and an incline range of 0 to 10 percent. The speed is adjustable in .1 mph increments; the incline is adjustable in .5 percent increments.
The ProForm XP 550E and XP 550S have pulse sensors on the hand rails. Wrap your hands around the sensors to check your heart rate anytime during a workout. The console offers 10 quick-set buttons. Press one button to set the speed. The LCD display shows the incline level, elapsed time, approximate number of grams of carbs you have burned, pace, distance, speed and the approximate number of calories burned. The console includes a cooling fan, accessory tray and water bottle holder.
Both treadmills offer four preset programs. Choose any of these four programs and the treadmill automatically adjusts the incline and speed settings. The XP 550E offers two heart-rate control programs. To use this feature, you must have a chest strap heart-rate transmitter. This accessory does not come with the treadmill. The first program allows you to set a target heart rate. The workout is divided into 30 one-minute segments. The target heart rate is the same for all the segments. The second program allows you to select a maximum target heart rate. A different target heart rate is programmed for each segment. The treadmill adjusts the intensity of the workout to keep your heart rate near the target heart rate.