How to find a treadmill which can be used for scientific studies?

https://www.treadmillreviews.net/how-to-fix-a-treadmill-motor/ 4. Treadmills tested by “fun testers” such as DC Rainmaker (*1) who say that “science sucks” (*2 ) are not suitalbe for scientific studies: (*1) The title of the above video is “Treadmill Accuracy Testing Fun”. If this is a fun test then as a consequence DC Rainmaker is a fun tester. (*2) In …