Indoor HR Low vs Outside - Ignore or does it Matter?

Background: Got back into cycling last year after 20+ year(!) layoff, I’m now 40yo riding road and gravel. In that 20 year layoff, I did lots of powerlifting/bodybuilding work - have decent amount of muscle in both upper body and legs - but still working on my endurance. Did about 1k miles last year - and now I’m obsessed and I’m at 3.2k miles already in '22. FTP ~230. I listen to the podcasts, signed up for a year of trainerroad this summer - did a base plan and now doing a short power build mid-volume plan.

My issue: even during VO2 max intervals, my HR doesn’t even approach what it does outside. Last 4 outdoor rides had max HRs in the ~170 range (176, 172, 174, 169). Did Bluebell +2 yesterday, legs were burning during the intervals, but max HR was 149 and I was mostly topping out at 142 or so during the intervals. Same HR strap. I have a lasko hi-performance fan on me too.

Should I just ignore HR and focus on power? I keep thinking that I need to work on my base more (i.e. my muscles are accustomed to short high intensity weight training and need to learn endurance) - BUT on group rides, I get dropped on the climbs (partly due to my weight :confused: ) and want to work on vo2 max level power.

Any help would be appreciated!

I don’t know if its right or wrong but for me HR has just been post ride curiosity for me since I got a power meter (2016 or 17 IIRC). HR is such a fickle thing anyway. Perhaps however, VO2max stuff unlimited outdoor is pushing your heart into the red whereas more controlled stuff indoors isn’t particularly in the VO2Max zone. If you are using ERG perhaps try switching it off and try pushing to the max into an oxygen based max rather than a power zone proxy of VO2max which can be off for some folk. I quite liked this podcast’s explanation on VO2max:

Watts Doc #23: Training Your VO2max, and Why Not Rønnestad 30/15 Intervals - Empirical Cycling

inside vs outside - same power meter and same bike?

My heartrate indoors doesn’t hit highs that I can outdoors (during races, typically). It’s nowhere near that type of gap though. More like 4-5 bpm which I’ve attributed to the extra mental work to ride in a group (or desperately hanging on the back of said group).

Do you sweat enough indoors for it to have a good connection? Lasko fans (at least the centrifugal ones that get brought up here) have a pretty targeted airflow and if it’s right on your chest/strap it’d perhaps evaporate without wetting the contacts enough.

Asking again - same bike and same power meter?

Outside rides - what are you doing?

Bluebell +2 is 5x1-min intervals and not very hard. If you have high anaerobic capacity, the target power may not move the needle much.

Same bike, but using the Kickr Core (calibrated) for power rather than the stages power meter. I have not compared them against each other though - I just use the kickr for power and resistance when bike is on the trainer.

Saying Bluebell +2 isn’t hard hurts :slight_smile: I think you are onto something that the outdoor rides have some more anaerobic ‘pop’ in them and I’m probably cherry picking the max HR on a much higher effort than Bluebell. For my outdoor rides, I live in SE Pennsylvania, lot of punchy climbs - it’s hard to get a 20mi ride without 800-1000ft of climbing in it. My standard outdoor ride is usually 1:30-2hrs, ~30-35mi, 1600ft of climbing - I try to sweetspot most of it, but will have to ramp up power for climbs.

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I’m usually the opposite because of having a better cooling affect outdoors.

I get a ~20 W difference between my Assioma PM and Kickr Core. I’d look into this.

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This would be worth doing.

When you say you did VO2max intervals outside, what exactly was the protocol for those? As @WindWarrior said, the 1 minute intervals in Bluebell might not be long enough to get your HR up. Additionally, if you’re doing the outdoor intervals on hills, you aren’t getting nearly the cooling effect of a Lasko (this of course is exacerbated because the roads in SE PA are coated in sandpaper and you move very slow).

Hey @RecoveryRIder! I’m so excited for you to be back on the bike!!

This is a great question. The short answer is, power is the principal metric you should be concerned with. If you are using the same power meter for your inside and outside rides, and calibrating this power meter before each ride, then this is the reliable metric that should guide your training.

I would suggest you use the Stages Power meter for your inside rides too. This will ensure you are comparing apples to apples. You can still use the smart trainer. PowerMatch is a feature from TrainerRoad that allows you to use your power meter to control the resistance on your smart trainer. Check out this article to learn more: PowerMatch: Using Power Meters with Smart Trainers.

There are external stressors that may elevate your heart rate when riding outside. If it is hotter outside than it is inside (with your fans), your heart rate may be responding to the additional heat stress. Furthermore, your body is keenly aware that you are less safe than when sitting on a very safe trainer in your living room! The sheer speed at which you are moving :zap: , the danger of riding alongside cars, or along sketchy trails can all elevate your heart rate significantly.

Finally, make sure you are comparing apples to apples:

  • Just because your average power was similar during an inside and outside ride does not mean the training stress was similar.

  • Make sure to have enough moisture on your heart rate strap to ensure a strong connection when you are training inside. You may wish to purchase gels specific to this purpose.

  • Use the same power meter for outside and inside rides, and make sure you calibrate your power meter before each ride.

If you are doing the above, you can be confident in using power to guide your training!

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:rofl: yes, you need to compare like to like:

  • same workout outside as inside
  • same power meter outside as inside
  • same bike (you are doing this already)
  • same HRM (you are doing this already)

only then does it make sense to talk about heart rate differences.

Like @SarahLaverty stated, use PowerMatch inside so that you have the same power meter inside and outside.

There is a lot of talk about HR differences inside vs outside, and this is my Ted talk about why they should be similar :joy: If you’ve done sufficient base training (low decoupling on longer endurance/tempo/SS rides), and you have discipline outside to follow target power, and temperature outside is reasonable and not too far from inside, and everything else is the same (time of day, hydration status, nutrition status), then I would expect inside and outside HR to be really close.

But if you leave the neighbhood and throw down some big power to climb a hill or deal with traffic, then your HR is going to go up and how long it takes to come down is dependent on the depth of your aerobic base fitness.

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