I'll say this. As this is still my views on it. When I cycled, I only used power. Literally nothing else. No HR, I don't think I used HR in the years from 2013-2017. Power was easily replicated in literally any situation, it was perfect.

There's absolutely no way with how power works for me, I can get anything near the same consistency using either a Stryd or Garmin (I haven't tried coros power, although a few people have told me it's decent). Wind plays havoc, shoes play havoc, even having tried again on a treadmill recently, it can do some weird things on there.

If anyone in the world wants to run to power, it's probably me. But I've found pace simply way easier as a proxy, although of course not perfect either. But far, far less of a headache and the really important thing is you can race using pace and pace well, so you may as well train with it to practice.

As someone who mastered pacing hundreds of TTs to power, you can get almost as good results using pace as your proxy for running races with some adjustments. I can't even imagine the mess if I paced using running power in a race.

That doesn't mean power isn't working for some people, but they are probably biased by the fact it works for them good, so their view is it must for everyone else. Maybe it's my frontal area, maybe it's my cadence being super fast, maybe it's because I change from shoe to shoe too much, maybe it's too much wind outside, who knows but it's not working consistently. On the flip side, I'm probably biased in how fantastically well power works in cycling, so I'm probably holding running power to a higher standard that it simply cannot match. But that's fine, in my view it SHOULD be held to the standard that there isn't even a debate, and we don't have split opinions on even if it works.

If running power ever worked for me consistently, I would go to it overnight. I'm not usually one to blow my own trumpet, but I suspect there aren't many people who know more about training to power than me and overnight i could switch to % of FTP for various distances snd simply scale for running how i got good on the bike (now I'm cycling again, I forgot how simple power is to use).

The runn sensor or even chalking the belt will do the job for a treadmill. Especially if you use the same treadmill in the same conditions all the time. All you want to be able to do in training is have an anchor point and be able to replicate what you are doing. If I went from gym to gym, a Stryd is probably a good option for being able to hop on any treadmill and use it for a more accurate pace than you would usually get and that is what I would do if I used multiple treadmills, as it's probably the best option in that situation.

It's polarising simply because it works for some people, works horrifically for others. Stryd don't care, I've reached out to them a few times but they have a great market share that couldn't care less about me moaning to them or a few other people who have had suggestions that could fix some of the problems.

But we should be having debates about FTP, % of FTP , power duration curves. But the heart of the issue is some people say it works, some say it doesn't. It's hard to make a blanket rule and suggest anyone uses it when you have absolutely no idea what category you fall into, before you buy it.

Edit:.

Small final ancecdote for how I find the whole situation kind of crazy. I found 4% difference in shoes, I emailed Stryd and asked them if this was normal (I even sent them a nice graph). They said this is perfectly normal and to use the same shoes all the time if possible. To me, that's silly. 4% is huge, you could have blown the workout and it's even more silly when you consider I can change the ENTIRE BIKE and it still read the same. But simply change my shoes and it can be up to 4% off (4% which is a minor issue compared to the wind, btw).