Treadmills The most natural of all the exercise machines and the most weight-bearing, Treadmills fit everyone and are fantastic calorie-burning machines. Gym Source carefully chooses clinically advanced cushioning systems along with the most durable Treadmill brands using our seventy years of experience. The expert ratings seem to agree, as Treadmill Doctor, Fitness professor, Consumer Digest, Runner’s World and many others in 2010 give top ratings to brands like Cybex, StarTrac, True Fitness, and Sportsart…which you can find exclusively at Gym Source.