When you use a treadmill is the distance and speed accurate?

Question

I am a professional athlete and I’m using a treadmill for long distance runs. How accurate is the speed and distance shown by the treadmill console?

Answer:

If you use a quality machine the distance and speed measured are pretty accurate. If the treadmill is new I think the difference between the real values and those shown is less than 1%. These machines have sensors that measure the actual speed and then compensate if needed.

If the treadmill is a used one some parts may not work correctly and the error percent can be bigger.