Treadmill speed accuracy? (Read 832 times)

    I try to never run on treadmills as I don't have one and also find it really boring.  But over Christmas week, I was at my brother's house visiting, and to keep things simple used his treadmill a few times.  Now, I'm not a very fast runner but in the last month or so I've been right around 30 minutes for a 5k and the last couple Parkrun measured/timed runs I've done here in Dublin (including one today) I've been at 29:30 so I have an idea of what my time for an outdoor 5k should be.


    The thing is, on the treadmill I ran what it said was 3.1 miles in about 38 to 40 minutes depending on the day.  The effort even felt harder than when I run outside even though it had a 0% incline.  I have to believe the treadmill was going much faster than the readout indicated.  Okay, so it was indoors and warmer, and I know treadmills vary in accuracy but is this sort of huge variation normal?  How do you know what you're actually running on a treadmill if it's not accurate?  Footpod for a Garmin?




      My treadmill runs are always slower than my outdoor runs (even in the snow). I find my cadence is quite different, and my pace is 30-60 sec per k slower.


      Not sure why, but I'm pretty sure it's normal.

        If you really want to know if your treadmill speed is accurate, you need to verify the speed yourself. There are a couple ways of doing that (google). Fwiw, I was told mine has a sensor that allows it to be as much as +/- 0.5 MPH before the TM considers it a problem.


        I used a measuring wheel to determine that at a variety of speeds, my TM is always going between 0.2 and 0.3 MPH faster than what the display says.  Now, I just compensate for that when trying to run specific paces.


        The other significant factor is the incline. Mine, when at 0 on the display, was actually at 1% incline. I computed this, roughly, with a 4 foot level and measures the rise/over run was about 1/2" (1% would be 0.48inches). I actually liked that though because I'd normally put all TMs at 1.0 or 1.5% to account for it being a TM and not running outside.

          Treadmill running is weird. i have run close to 1000 miles on the mill over the last 2 years (although somewhat less frequently the last few months) and I run much much slower inside and seem to work harder to achieve it. My easy pace is about 8:30 - 8:40 outside but it is slower than 9:00 inside and I never use any incline.  It is not because it is hotter (live in fl so it's normally cooler). It's just the way it is and I recommend you don't worry too much about it. I suppose it has to do with perceived effort and I guess I perceive running on the mill as harder than outside.

            Treadmill at a given pace always feels harder to me than running outside. I think it has a lot to do with how the treadmill alters my stride. Could be a mental thing, too.

            Feeling the growl again

              There is no one answer.  In general, if the treadmill is accurate, it feels harder than running outside to most people.  I have manually checked the accuracy of a good number of treadmills and there is a pretty wide variation in their accuracy....and it is not always linear.  My current machine is accurate until roughly 10mph, then it starts to diverge.  By the time I have it up to ~11.5mph I can do tempo runs faster than I could race outside.  When I get my hands on a wheel I'm interested in how far it may be off, but I'm guessing it's running about 15sec/mile slower than it says it is at that speed.

              "If you want to be a bad a$s, then do what a bad a$s does.  There's your pep talk for today.  Go Run." -- Slo_Hand


              I am spaniel - Crusher of Treadmills



                I measure and mark the belt, then count rotations while I'm off it and while I'm on it.  Especially with the cheaper / older / more beat up treadmills, it slows down pretty hard when it has someone on it -- I've seen some that are as bad as 10% slow.  I don't find too many treadmills that run fast -- I'm guessing differences in perceived difficulty are the result of some combination of (1. more boring (2. a different type of required stride or (3. having heat build up around you (is there a fan on while you're running?).


                  I agree that treadmill running feels a little harder than running outside. It may be that you are forced to land on a moving surface. If you have a HR monitor, you can try to compare the level of effort.


                  as far as accuracy, it really varies widely from treadmill to tradmill. Check YouTube on how to check the TM calibration. It doesn't look hard, it just takes some time.


                    I've found the same thing.  My theory is that when the foot lands it slows down the belt a little absorbing some of the energy that would normally be pushing up on the foot.  So in effect there is less rebound from the footstrike.  Presumably a heavy duty mill with a large flywheel would reduce this effect.

                      Thanks to everyone for the replies.  It sounds like what I experienced was pretty normal.  It was definitely a bit alarming to see a change like that between outdoor pace and treadmill pace.  Now that I'm back home, I'll resume doing just outdoor runs for the most part.


                        I am in the minority and find that I can run faster more easily on the treadmill. I think it's because in my mind I'm forced to run faster - in other words, if I set the treadmill at 8.5mpm, I'm "forced" to stick with that where as on the street if I'm doing intervals, I find I can easily slow the pace before the interval is over. I am strange in that I don't mind the treadmill especially since I run so early and sometimes it's just safer to stay inside as opposed to venturing out alone (I do run with someone a few days a week, but there are days I'm solo). However, I sometimes question if "it counts" as much as running outside. I do have a friend who is super fast, she wins overall female (or top 3) at most of the races by me that she runs and does all her training on a TM. And she never puts the incline on, always runs on a 0%. I know she has some born talent, but it makes me believe that treadmill training is not that far off.


                          I've been running on my TM for over two weeks due to sub-zero temps and ice covered streets. Today when I finally got outside I was concerned about it being a rough transition back to the road. Not at all! I felt stronger today than I did on most of my runs pre-TM. I think keeping a constant pace, a bit faster than usual, and using the incline frequently has actually helped make me a stronger runner. I've never bothered to calibrate mine to check for pace accuracy, and while I vary the incline throughout my runs, I don't always set it at a particular incline %. A lot of my miles are done at 0%.

                          PR's: 5k - 23:33/ 10k - 48:30/ 5 mi. - 39:21/ 13.1 - 1:53/ 26.2 recent - 4:34


                          Upcoming races: Resolution Run HM 1/1/13

                                                      Phoenix R&R    HM 1/20/13


                            I used the nike+ on all the TMs in the gym and they were all different. Some fast some slow.

                              My Garmin seems terribly inaccurate on the treadmill.

                              Well at least someone here is making relevance to the subject. - S.J.

                                Another minority here. I run faster on TM than on road. BTW Michael, did you run on a Landice TM? I have found all Landices including mine to be faster than it says.

                                running is somewhat like playing golf to me.   crappy shots all day long, ready to give it up & wondering why I'm trying so hard just to get this stupid little ball into a stupid little hole but then out of the blue comes a monster drive or a long putt that actually gets into the cup.  bingo! that one shot keeps me going for the rest of day no matter how crappy I continue to play & gets me back out again on another day.   strange. -- skyedog