Guides · Does treadmill count as steps
Does a treadmill count as steps? Yes. The miles are the part to doubt
You step off the treadmill and your step total looks right. Then you notice your watch says 2.8 miles and the treadmill says 3.1, and you wonder which number to believe.
Yes. In a 2017 lab test on a treadmill, most trackers counted steps well, but none matched the treadmill's own distance well, so your step count is the number to trust most. The miles are where your watch and the treadmill split, because each shows its own reading and neither is checked against the belt.
A step is the part your watch can count
Your watch carries a motion sensor, the accelerometer, and indoors that sensor is what it works from.
Researchers put this to the test in a lab. People walked and ran on a treadmill wearing eleven different trackers, while a light sensor system on the machine and a hand count checked the steps. Most of the trackers counted steps well. Not one of them matched the treadmill's own distance well.
Your miles are a guess, on your wrist and on the machine
Indoors, your watch has no satellites to follow, so it has to work out distance another way. An Apple Watch falls back on the stride it learned on your outdoor walks and runs. A stride learned outside is still a guess about today.
Think of pacing off a room to see if a couch will fit. You can count your paces perfectly. The size of the room still depends on how long you think each pace is. Guess 2.5 feet when your pace is really 2.3, and the room comes out bigger than it is.
The same 5,000 steps, three stride guesses
These are made-up numbers to show the idea. No watch maker publishes its exact method.
The step count never moved. A modest change in the stride guess moved the distance by almost 0.4 miles. Over a week of daily walks, that could add up to more than a whole walk.
The treadmill's miles come from somewhere else. The display shows the machine's own reading, and your watch does not see it unless it is paired with the machine. Nothing on your wrist checks it against the belt. So when the two disagree, you cannot tell which one is off. When they agree, that still does not tell you how far you went.
Holding the rails costs you accuracy
At least one watch maker's manual says it outright: holding the treadmill handrails reduces accuracy. That means the speed and distance the watch works out indoors, and the manual does not say by how much. If you grip the rails on the hills, the guide on what holding onto the treadmill changes covers what else shifts.
Your steps say how much you moved. The belt says how far.
A step total is a count, and counts hold up well. Distance needs one more fact, which is how fast the belt under you really moves, and neither your watch nor the treadmill gives you that. The machine's own distance can be far off too. On one of the machines I run on, the display said 5 miles. I had run 4. It is the largest gap in my own tests.
Treadwell gives you the missing fact. Stand on the floor beside the machine and hold your iPhone Pro above the belt. Treadwell reads the belt's real speed through the camera and the LiDAR sensor, so your time on the machine becomes a distance you can trust. If your watch and the treadmill keep arguing, the guide on why your watch and treadmill never agree shows what each one is doing, and what your Apple Watch really does indoors explains the stride it learned outside.
Turn your belt time into real miles
Read your treadmill's true belt speed before your next walk or run. You need an iPhone Pro, because Treadwell reads the belt with its camera and LiDAR sensor.
Scan with your iPhone Pro to get the appTested: in our tachometer tests the app read within about 2 percent of true belt speed.
Quick answers
Does treadmill count as steps? Yes. In a 2017 lab test on a treadmill, most trackers counted steps well, but none matched the treadmill's own distance well, so your step count is the number to trust most. The miles are where your watch and the treadmill split, because each shows its own reading and neither is checked against the belt.
Does my watch count treadmill steps if I hold the rails? One watch maker's manual says holding the rails reduces the accuracy of its indoor speed and distance, without saying how much or whether the step count itself drops. If you need the rails on a hill, treat that stretch's distance as unknown rather than trusting either number.
Why does my watch show fewer miles than the treadmill when my steps look right? Usually because the miles come from two different places. Your watch works out distance from your movement, and the display shows the machine's own reading, so matching steps do not make the miles match. Do not assume either number is right until you know how fast the belt moves.
Should I log steps or miles from a treadmill walk? Log the steps with confidence, because watches count them well. Treat the miles as an estimate until you know how fast the belt really moves. Once you know the belt's true speed, the time you spent on it gives you a distance you can trust.
Sources.
- Steps counted well, distance not: Wahl Y, Duking P, Droszez A, Wahl P, Mester J, "Criterion-Validity of Commercially Available Physical Activity Tracker to Estimate Step Count, Covered Distance and Energy Expenditure during Sports Conditions," Frontiers in Physiology 8:725 (2017). Twenty sport students walked and ran on a treadmill wearing eleven trackers, nine of them on the wrist (one was later left out of the analysis); steps were checked against a light sensor system on the treadmill and a hand count. Most trackers showed good validity for step count, and none showed good validity for distance, which the study measured against the treadmill's own calibrated distance. The trackers were 2017 models and no Apple Watch was tested.
- How a watch gets indoor distance: Apple Support, "Calibrate your Apple Watch for improved Workout and Activity accuracy" (article 105048), which says the watch learns your stride on outdoor walks and runs and uses it when GPS is limited or unavailable; Apple Support article 105002, which says indoor runs use the accelerometer.
- Holding the rails: Garmin Forerunner 165 Owner's Manual, Indoor Activities: "speed and distance are calculated using the accelerometer in the watch" and "Holding the handrails of the treadmill reduces accuracy."
- Our own test: the 5 versus 4 mile run is my own, from one of the machines I run on. The machine and the date were not logged.
- Invented to explain the idea: the 2.8 and 3.1 miles in the opening, the 5,000 steps and the three stride lengths, the room, the couch and the 2.5 and 2.3 foot paces.