NordicTrack elliptical machines are made by Icon Health & Fitness — one of the largest sellers of retail fitness equipment. Because they are made by such a large company they are able to have a large number of engineers working on their product designs and features, so the machines are generally pretty innovative. This also gives them the ability to offer a little better quality elliptical at a lower price.
NordicTrack offers a few different types of elliptical machines. For example they have a commercial series featuring ellipticals that are built as a gym quality exercise machine meant for a lifetime of heavy use. They offer an incline series that has a focus on their 30 degree motorized incline ramp. They also offer a space saver elliptical series that allows you to