Treadmill long run pace accuracy?

i keep track of heart rate on every run. within a given speed, i am always faster outside than on a treadmill. and i don't mess with incline. it's not really necessary in my experience.

the treadmill is fine. i know people who have gotten in the best shape of their lives running strictly treadmill miles. The ingebrigtsens do a ton of treadmill work as well.

high school xc coach wrote:

the treadmill is fine. i know people who have gotten in the best shape of their lives running strictly treadmill miles. The ingebrigtsens do a ton of treadmill work as well.

I like the (calibrated) treadmill in winter for intervals. Time passes by more quickly.

And a big plus is that you can play around with different interval ideas and you have stable reproducable conditions and you can compare performances pretty well.

I'm the opposite of most runners as I like the treadmill indoors when it's warm outside, anything above 66 degrees or so.

Running in the cold outside is a gift.

If you are that curious if it's accurate, just measure it out like others said. It's pretty quick and easy. My treadmill was giving me surprising numbers too so I measured it and they belt and screen were a little off.

The best thing I noticed is to check HR. I have the Garmin with wrist HR and I check occasionally to see if it's close to the same numbers as outside. As long as the effort is the there, the treadmill is great. I use mine all time. I don't worry much about the pace or incline to make up for being inside. I just run what feels right and it's worked well.

San Diego Hobby Jogger wrote:

peloton likes to beef up numbers for users to make them feel special. For instance the bikes add 200w of what a user can really do in real life. generation #snowflake.

Where do you get that from? I have a peloton and I think it is pretty close. I’ve used a power tap for over 10 years and my numbers line up nicely. Are you listed at 450 lbs in your profile or something? Are you 450 lbs?

I wouldn’t worry too much. You got a peloton tread, so those pesky kids should be gone in no time and you can start training outside again.

CopperRunner wrote:

It’s kind of a question of running/body mechanics.

For me, I’d say treadmill running is a bit more difficult, because I overheat super easily and have to run at a faster cadence that feels unnatural starting at about 6:00 pace.

The general consensus is that 1% incline adjusts for wind resistance, so it’s possible you can run even faster.

It’s possible that with a new treadmill the belt isn’t calibrated though, you should look up and see if your treadmill bases distance off of belt rotations, or what the pace is set to on the dashboard. It’ll for sure be accurate with the former, but may require calibration with the latter.

My treadmill is wildly inaccurate. I've confirmed this three ways:

(1) I put a mark on the belt, measured the belt, and then counted revolutions per time. Simple mathematics confirmed that my treadmill belt was slower than the display stated.

(2) North Pole Engineering Runn sensor. I used one of these until it met an early death. You put a reflective strip on the belt, and it measures how long it takes the reflective trip to travel from one sensor to another. It was consistent with my own measurements.

(3) Stryd foot pod. When my Runn sensor died, I started using the Stryd. It was consistent with the Runn.

The Stryd tells me something interesting that the other methods couldn't. My cadence when running on the treadmill is about 6 SPM higher than running on the ground, and my stride length is shorter. This is a little bit interesting because my perceived effort on the treadmill is higher, probably because of the higher cadence, but my average heart rate is not actually higher.

So for someone like me who has insanely long legs and a slow cadence, mixing in a treadmill run here and there seems to be helpful for a variety of reasons. But I have to ignore the treadmill speed because it is wildly inaccurate.

I have tested my treadmill calibration on various treadmills -- never seems to be exact. My current one (Sole F80) is so far off that 1 mile on the treadmill screen is actually 1.08 miles based on the belt/calibration. There is no way to recalibrate the computer (which I find insane).

Anyway, I have decided that you can't compare treadmill pace to outdoor pace. You just run by HR on a treadmill to make sure you are working in the right range for the day, and whatever the screen say, just shrug it off. I don't even go by perceived effort, because studies have shown perceived effort at the same pace is higher on the treadmill (I guess due to boredom or perception of motion?). Not usually a huge HR training guy but on treadmills it helps for me.

Mr. 800m wrote:

BTW, I never run on an incline. It's kind of pointless. What scientific proof backs that a 1% incline "emulates outdoor running"?

It doesn't emulate outdoor running... it increases the effort to offset the lack of wind-resistance to try to make the treadmill pace effort closer to the outdoor effort.

I agree that it is somewhat pointless. You could also just run slightly faster on the treadmill to get an equivalent effort.

Anecdotally, my stride feels more natural at a slight incline .5 to 1% when on the treadmill but I try to vary the incline during my treadmill runs between 0%-2.5% (I just bump the incline up and down on the fly during the run) in an unscientifically approached attempt to reduce the risk of repetitive strain injury.

During running the body generates a lot of heat.

I have the luck that in my gym i am able to tilt or open the window which is very close to the treadmill. This provides me with fresh air, and even more important in winter with cold air. This cools down my body and this has a hudge influence on heart rate.

So the cooling effect is very important which is there outside, because of the air resistance.

connoisseur wrote:

Mr. 800m wrote:

BTW, I never run on an incline. It's kind of pointless. What scientific proof backs that a 1% incline "emulates outdoor running"?

The lack of air resistance has been discussed for years but here's a quick search hit for you -

https://pubmed.ncbi.nlm.nih.gov/8887211/

For lack of air resistance, you could increase the speed very slightly rather than make it a slight incline. The whole 1% incline rule of thumb is dumb. If you want to go up hill or vary the incline, go for it though.

Most decent quality treadmills will be calibrated well enough for your purposes, but I’ve been on a couple at health clubs over the years to tell that they were too “easy” for the pace.

If you had incline at 1.5 you’ll really easily replicate the workout outdoors in good conditions.

I guess at the end of the day treadmill companies are aiming to provide a machine for the masses, not anal, meticulous runners obsessed with accuracy and exact analytics.

CopperRunner wrote:

The general consensus is that 1% incline adjusts for wind resistance, so it’s possible you can run even faster.

Agreed with everyone that running at pace X:XX is going to be easier on a treadmill than outdoors.

But I find it so stupid that some people make this adjustment with incline rather than pace. Why not adjust speed??

Honestly I do 15-20 miles and 6 min pace on the treadmill a few times a year. Feels similar to my 6:15 outdoors on a fairly flat terrain. So while it differs 5:50 is probably around 6 flat or slightly faster with 1% incline.

bio Domer wrote:

connoisseur wrote:

The lack of air resistance has been discussed for years but here's a quick search hit for you -

https://pubmed.ncbi.nlm.nih.gov/8887211/

For lack of air resistance, you could increase the speed very slightly rather than make it a slight incline. The whole 1% incline rule of thumb is dumb. If you want to go up hill or vary the incline, go for it though.

The incline simulates a force in the opposite direction you're running. That's why people anecdotally say the 1% incline feels more "natural." Like I posted earlier:

Hardloper wrote:

The incline simulates a force in the opposite direction you're running. That's why people anecdotally say the 1% incline feels more "natural." Like I posted earlier:

https://www.codybeals.com/wp-content/uploads/2014/02/Runner-treadmill-free-body-diagram.png

Puts unnecessary strain on my Achilles, personally, but I might be a wimp.

How old are your kids? I hire a sitter when I need to run and my husband is working. Funny that when it’s your turn to parent, you run for an hour 45 mins on the treadmill

San Diego Hobby Jogger wrote:

peloton likes to beef up numbers for users to make them feel special. For instance the bikes add 200w of what a user can really do in real life. generation #snowflake.

That would give me almost a 7W/kg FTP; how do I sign up? :)

I know that does come across as quite selfish. That was my first run of the week since I do take over child duties when I get home from work. However, we have great twins who just turned 1 and both still nap like crazy. I decided I would run until they woke up and had their cribs in the room the whole time so I could watch them (the sound of the treadmill always makes them extra sleepy for some reason, haha).

Thanks everyone! This is all interesting to read! I also just realized the peloton has a calibration feature.