http://articles.mercola.com/sites/articles/archive/2002/04/24/treadmills.aspxEllipticals are among the most widely used machines in health clubs, and the number of people using such machines increased from 2.4 million in 1997 to 6.2 million in 2000. Elliptical exercisers are combination stair climber/cross-country-ski machinesenCommunityServer 2008.5 SP1 (Build: 31106.3070)