I was wondering how accurate is the Fenix 3 for indoor run on a treadmill?
I never calibrate my Fenix beside running outdoor a few times. My understanding is that after x amount of outdoor run, it will ‘learn’ your pattern and used it to calculate your indoor pace along with the internal accelerometer.
My setup:
Free Motion treadmill
1% grade - speed: 8 mph and slowly incremental
Fenix 3 without foot pod nor HRM
From Garmin Connect:
distance: 10k
avg run cadence: 207
max run cadence: 225
On a 10k run (record by the Fenix), my treadmill run distance is never near 10k mark. It is always off by quite a bit. (I forgot to record the exact distance) Even if the speed is ‘low’, I always make sure to keep a fast cadence. Increasing the speed of the treadmill slowly only help me to not ‘slip’ due to increase of cadence.
I understand that a treadmill cannot totally be compared to an outdoor run due to many factors but I am using the time as a benchmark to keep improving. So if give and take, how far off is the time from indoor vs outdoor? Is it right for me to say that if I can run x time at this x pace indoor, I should be able to do approximately the same outdoor?
We have a NordicTrac, and after > 6 months, I have not found that the Fenix has “learned” my speed/distance, at least according to the treadmill. There’s always a difference, which is longer on the treadmill than on the Fenix.
My limited experience with the F3 internal accelerometer is not good e.g. recording 4:00 min kms when it the actual pace was much closer to 5:00 min kms, so not even vaguely close.
In my opinion, you’d be much better off just judging it by RPE or just going with the treadmill stats and accepting that there will be a difference between your indoors and outdoors numbers. If you’re going to be running indoors regularly, a footpod or a HR monitor would be a good investment to attempt to bring those indoors and outdoors numbers more into line with one and other.
I use the footpod with my Fenix 3 when running indoors (I run on an indoor track, rather than a treadmill). Once calibrated, I find it’s quite accurate - to within 2%
I have a Garmin FR235 and the treadmill measured speed (by the watch) is usually pretty close to whatever my last outdoor pace was as measured/learned by the GPS. I usually run a bit faster outside than inside, so the Garmin always shows me as having gone faster/farther than the treadmill display. I guess my steps per minute and/or distance per step vary between outdoor and indoor? Somewhat frustrating, but I end up just using the speed and distance from the treadmill itself as the authority on my indoor pace and distance, rather than the Garmin. Garmin says that running outdoors is the only way to calibrate the accelerometer, (link here). My experience is that you should be able to use your treadmill displayed pace/distance as a reasonable indicator for what you should be able to run outdoors, unless there is some reason that you doubt the accuracy of your treadmill?
Now I know that the above pace is totally different from both runs as my indoor run was a easy recovery run compared to the outdoor run.
My assumption was that if you increase your cadence, you should be moving faster no matter what your treadmill set speed is. Basically my theory is that the speed of the treadmill only dictates the distance shown. For example, I can set it to 10 mph and actually not running that fast because I have a low cadence and just let the treadmill ‘push’ me.
aahhhh… That is not good news for me. I really thought I improved a lot after yesterday hard run. If it is off by that much (pace), I am nowhere near where I should be to hit my goal.
I was looking to buy a foot pod for the past few weeks but they are $80 CAD new. Hopefully I can get my hand on a used one in the near future.
Also, most treadmills are woefully inaccurate with the speed and pace reported on the display. Most of them at my gym go way faster than reported, by up to 1:30/mile pace. Mine at home runs just a hair too slow at 8-minute-mile-pace, but around 7 it’s spot-on.
Tell me about it. They’re £45 in the UK, on top of the already considerable expense of the Fenix 3, but IMO it’s totally worth it to get reliable pacing data. Even when GPS is behaving well, you’ll still get better results with a well calibrated footpod.
I’d caution against buying a used one however; they do fail over time, see my previous thread here and fellrnr’s summary here (section 8). If you’re buying an old model with a few thousands miles on the clock already, then it might not last as long as you’d hope; given the prices that second-hand ones go for in the UK (~75% of new) I’d say it’s a false economy.