yesterday I jumped on the trainer for the first time in ages, and what I noticed most was that my RPE was so much higher for the same heart rate than outside. What can cause this?
I know that the monotonous strain (no coasting), lack of wind, somewhat higher core temperature, can all contribute to this higher RPE, but I’m worried that I’m not getting the same benefits if I’m working out at a lower heart rate all the time when inside.
To give an idea, when I ride outside I would give 150HR a 4 out of 10, inside this was easily a 6.
The core of the question: for max benefits, should I ride to RPE or HR?
You’ve basically summed up the reason for the RPE difference, no coasting, no variation in terrain and I include boredom too.
Due to the lack of cooling, e.g no wind then often HR can be higher as your body is having to work hard to keep cool.
Do your best to ride to HR and then learn to hold the effort. Say for example you’re doing a 15 minute Sweetspot interval, then your HR will take time to get to the correct level but try and hold that effort the entire interval regardless of what your HR does. I’m guessing you don’t have a power meter, so you could use cadence to keep your effort consistent, e.g once you’ve found the correct gear, hold on to that gear and the same cadence and in theory you should hold the same power through all of it.
Except the OP is talking about RPE at the same heart rates - not that HR is higher indoors.
This is what’s odd - you’d expect to see RPE go up in line with heart rate.
@JorritK is your outdoor riding off-road? Are you using your upper body more? Are you getting out of the saddle more? You might see a lower HR relative to RPE indoors if the way you’re riding on the trainer is very different to outdoors.
Also, are you riding with a power meter? If so, what kind of powers are you seeing at this HR indoors and out?
Edit: other thing that occurs to me is the gear you’re in and the type of trainer you’re using. If you’re in a low gear on the turbo trainer and/or the trainer has low inertia (i.e. it stops quickly if you stop pedalling), this can create a very different “feel” to outdoor riding as you need to be pushing all the way round the pedal stroke.
my outdoor riding is on tarmac most of the time. Biking-wise I don’t think I’m doing many things differently: I’m on the hoods, my upper body is relaxed, I try to keep the cadence about the same (85-95). I am on a different bike (older one), but if that one has more drag/less well-lubed parts that would influence power @ HR, not RPE @ HR.
On my road bike I have a power meter, the bike I have on the turbo doesn’t. I compared the two by riding on a fixed power for 5 minutes, and the estimated power on the turbo is much lower for the same HR than outside (150W @ 150HR inside vs 150W @ 120HR outside). However, since one is direct measurement and one is estimated based on wheel speed I don’t think there’s a good comparison to be made.
Your last point is interesting, I am indeed in a low gear (not exactly sure, but let’s say that it’s 39-20 indoors vs 50-20 outside for about the same cadence/rpe feel). The roller stops spinning very quickly indeed.
I would definitely explore this as a possibility in that case. Sounds like you’re on a non-smart trainer as you talk about estimated power (btw I agree in that case that there’s no point comparing it with your on-bike power meter). Which means that pedalling will be meeting constant resistance and feel more akin to going up a steep hill outdoors - i.e. you need to keep pushing on the pedals or else you’ll come to a very quick halt.
If you know anyone with a smart, direct-drive turbo trainer maybe you could ask to have a go on it and see if it feels different. Or just buy one if you’re having a good year and have some cash spare!
Try shifting into your fastest gearing on the trainer and evaluate the feel as well as the spindown time. Compare this to the slower gearing inside, as well as the feel outside.
Might make sense to do a few more rides to see if this persists. RPE at HR can vary for a bunch of reasons - tired, sick, under fueled, under hydrated, caffeine, etc.
If the feeling is the same after 2,3,4 more rides, then you can be confident there’s a real difference.
This is an extreme and not directly applicable example of HR vs RPE, but does show how the relationship can be way different day to day: - yesterday evening I rode in our local XC race, 172 HR average for 1.5 hrs. For the last Main climb at Leadville on Saturday, my HR averaged 137. RPE was higher for the Leadville climb, despite 35bpm lower HR.
I think a lot of the other suggestions above make a lot of sense but wanted to highlight one possibility that I feel raises RPE for me indoors
Lack of distraction
When you’re riding inside there is not much there for you other than the sound of your heart pounding in your ears or the countdown until the interval ends
Riding outside you have other riders to chase, the scenery, tons of things
Not a sure fire fix - but find something that can engage and address the mental challenges of indoor training and it might help resolve this issue
I think get your cooling setup right and train to HR. If higher RPE indoors is just a mental thing, you’ll get used to it, or find some way to distract yourself.
If virtual power can give you a repeatable/consistent power measurement, you can also use that. Eg do an FTP rest using virtual power, and use that to inform your workouts.
I also find my RPE to be higher indoors and so have adjusted my HR zones indoors using 10 beats less for MHR than outside heart rates and adjusting the zones accordingly. My cooling is fine . Once your comfortable with your HR settings then keep this a your baseline. Threshold for me is mid zone 4, VO2 is high z4 edging into z5 at extreme efforts.
In my opinion you might have a higher RPE because you’re getting back into indoor training. We all like riding outside more. So, it’s kind of a bummer that we have to go back into the pain cave. Which makes me wonder if the higher RPE it is more in your head than your body.
To answer your other question. Training to power would be best, but you don’t have power. The next best thing is HR. Then training to RPE.
One thing you might want to consider is getting a better fan or more fans on you during the workout. I train in my basement. In the winter I’ll open a window and get the fan blowing on low. I’m cooled well and can do a lot of work then. But, when it’s warmer and more humid in my basement I need to open all the windows and get a few fans going and I’m really busting a sweat in no time at all.
Also, I would not necessarily try to compare apples to oranges regarding your HR and RPE correlation. Keep comparing your outdoor workouts to other similar outdoor workouts. While comparing your indoor workouts only to your indoor workouts.
One of the biggest differences between indoor vs. outdoor is mental distraction.
Outdoors even at same power and HR your mental capacity is focusing on multiple things which you are processing; what line you are riding, scenery around you, passing motorists, etc. Indoors its just you and the blue bars and trying to keep target power. The mental distraction simply isn’t there and you begin to focus on your; breathing, heat, lactic burn, etc. This I believe is what increases the RPE.