Heart Rate not getting up like outdoor rides

Hey,
I’m in a build phase program and I’m noticing my HR on over unders or workouts with intervals at 125% FTP I.e bashful, fang mountain, my HR only gets around the 150-160bpm. I don’t ride to power outdoors and only virtual power indoors. My ride on the weekend when trying to push some intervals I could easily get up in the 175bpm+. If i tried to hit those numbers on the trainer I’d fall off or only hold it for minimal amount of time.

Anyone else experienced this? I’m wondering if my workouts are not pushing me enough if I’m finding things harder on the road? Though they seem pretty tough when I’m completing them at the time. Very rarely have to increase the intensity.

How much attention should I be paying to HR anyway?

I’m 31yo, riding roughly 7hrs per week.

Be interested to see what others have experienced. If I could afford it I would get a power meter but I cant right now unfortunatley

Cheers in advance,

I wouldn’t worry about it, I see similar discrepancies, HR very rarely gets to 170 indoors and when it does I’m in trouble and often can’t finish the workout! Outdoors in a hard group ride or race I’ll hit 170 frequently and with significantly lower RPE and HR spikes to mid 180s in something like a sprint finish. E.g. Last week I did a group ride where my average HR was 172 and barely dropped below 170 for a 15 minute section finishing in a sprint where it peaked at 183. The week before I did Baird+6 and my HR didn’t hit 170 until the penultimate of 15 VO2 intervals by which time I was in a world of suffering.

Not sure what the reason is. Maybe temperature related as at the moment it’s a fair bit hotter outside than my air conditioned trainer room. Maybe the ability to throw the bike around more outside means I utilise more muscles and suck up more oxygen. Maybe it’s the adrenaline and excitement of racing other people. I don’t think it’s motivational - I’m pretty good at suffering when I want to. It’s not just high intensity rides either - my HR on an easy ride like Pettit is also a fair bit lower than an equivalent easy spin outdoors at similar power. Doesn’t seem to be holding me back in any way, so I just ignore it and don’t try to compare HR indoors and out.

Cheers!

Sounds exactly like everything I am experiencing to date. Despite the higher HR at times i feel like I’m getting stronger when I finally do get outside and that’s all that counts I guess.

Maybe I just have to try and hold myself back a little more when I get out alone. Easier said than though…

Thanks for your input!

I too have noticed its hard to get my HR up very high indoors. Reasons are numerous in my opinion, but limited competition and adrenaline are probably high on the list. So i have adjusted my indoor HR’s as roughly 10 bpm lower for indoor settings on my Polar GPS and work to this in conjunction with power and the efforts seems comparable with outside workouts.
As long as you know what your expected HR’s are , both indoor and outdoor, you’ll make progress.
I’ve also found virtual power to vary in different power zones with actual power, so again just record what levels you’re working at and benchmark training on them.