Is giving up on accurate TM pace/distance best?

Douglas Sutherland

Prior to '14-15 OS, I would assume the data spit out by my TM was accurate and didnt pay much attention to HR (sweating was perceived as good). Then '15 IMStG happened. It became clear 1) going outside matters, 2) hills matter, 3) my TM data is not accurate. My TM consistently appeared to be reporting my runs at a faster pace than was actually happening (even at a 2-3% grade even).

I bought a Garmin 920xt this year. Using the watch (Run Indoor mode with the new HR strap) on the TM seemed to confirm what I was thinking - my TM said I was running a 7:45 mile while the Garmin said I was running a 8:20. Further, my HR seemed to trend more accurately with my Garmin (assuming I was not actually getting in better shape - which I was, made clear by my IMAustin results). The net result of this was simply putting my watch on HR and trending that (especially since EN guidance now heavily weights HR during the actual race).

But then I received a foot pod for x-mas. Prior TM forum conversations left me with the understanding that the foot pod was the most accurate way to monitor TM pace - true?. I put it through 3 outdoor runs to calibrate, then took it inside. Now, my watch (using the footpod) suggests I am actually running faster than the TM suggests While my initial take on this is that the watch/footpod is not accurate, I also am beginning to feel like a hamster in a full sprint on the TM - the rate at which my legs are going 'feels' just as fast, if not faster, than my outdoor runs - though my perceived effort and HR do not seem to match my outdoor runs regardless of the quick cadence (again at 2-3% grade). 

The only reason this matters to me really is because in the OS we are back to tracking distance - 24 miles this week, 26 next, eventually 30, etc. I have no choice but to do 2-3 runs on the mill each week. 

 DS

Al Truscott

My thought: test outdoors on a track or 5K race to establish HR zones, then use those as your primary metric on the treadmill with a fan to contrl body temp. Stop using 2-3% incline; that will shorten your stride, and part of training is to get your body used to what running in various zones feels like. I use 0.5; others use 1%. Save the hill training for outdoors.

Tom Box

I agree, 2-3% incline seems a little much for regular running on the treadmill. I think the coaches recommend setting it to 1-2%. If you calibrated the footpod outside on relatively flat ground and then run at 2-3% inside you will definitely see differences because of a shorter stride. I've noticed several things affect my footpod pace inside. Changing shoes can affect the angle the pod sits on your shoe. Even placing it on a different section of shoelace affects my pace reading by as much as 3%.

MattAaronson

Posted By Tom Box on 09 Jan 2016 12:59 PM



If you calibrated the footpod outside on relatively flat ground and then run at 2-3% inside you will definitely see differences because of a shorter stride. I've noticed several things affect my footpod pace inside. Changing shoes can affect the angle the pod sits on your shoe. Even placing it on a different section of shoelace affects my pace reading by as much as 3%.

Totally consistent with my experience. I usually adjust the calibration factor to roughly match the TM as I have come to the conclusion that most treadmills are reasonably well-calibrated and I like to have my runs tracked in Garmin Connect and TrainingPeaks.I did a whole post with data collection a few years back comparing a whole ton of treadmills I ran on literally across the world but with the exact same footpod calibration and if I recall correctly the upshot of it was that with the exception of the odd treadmill that is way out of whack, most are really close to one another. None can be compared with outdoor paces...it is a different workout.

morpheus

all that being said, I've gotten into a groove where I use the treadmill for time and HR, no matter the speed. If my goal is to keep the HR down, I ignore the mph and focus on form. Then, will almost always finish with a handful of accels/strides/sprints/RPE stuff. If my goal is mile repeats, I get the mph as close as my RPE memory serves me. Knowing that all treadmills feel a bit differently due to the cals, it settles into a mph ballpark but confirmed by RPE and HR.

I don't worry about the perfect match of the gym's calibration to my outdoor pace anymore. Just not worth the mental cost, IMO.

{been wanting to get the footpod but haven't, yet. not sure if I ever will as long as I feel this ^^^ way}

Shaughn Simmons

Al has it.  No better advice here.

Credible studies have shown that no more than 1% incline is needed on the TM to better approximate outside running.......and, if your running at 8 min/mile or slower no incline at all will do.

SS