Heart rate vs power question

[Roo]

I’m newer to cycling, but have been doing endurance running for a little while. I tested my FTP when I started cycling and got 245.

However, now as I complete coach jacks workouts, my heart rate seems to be too low for the intensity I expect. Eg. VO2 max session today my heart rate maxed out at 140. It seems as though I won’t be achieving the desired adaptions from a VO2 max workout with such a low heart rate. My easier workouts have a heart rate around 115. For context, my max heart rate is 193.

Do I need to wait for my leg strength to match my cardiovascular ability? Should I retest my FTP? Any advice is welcome! Thanks

[Alex]

Hi. Starting with 245 is nice So there is three different concepts to this response
First
So, we once had a customer like you that they had a strong disconnect between HR and power. So because of this, this guy could ride for hours at 90% of his FTP. It sounds like in your case you might be aerobically very strong but that is not represented in your FTP.

Second
Our workouts are a bit different in that we start easy and build to hard. Each week is preperation for the following week, so the intial goal is not to push you to very hard VO2max efforts. All this said it sounds a bit too easy.

So the initial VO2max workouts will generally start easy but if you can send me the link from your activities page from TrainerDay to show me the workout or put a screenshot here that would help.

Third
VO2max efforts are limited or strongly affected by your anaerobic work capacity (AWC or W’) more than your aerobic capacity. So Coach Jack does not factor in your W’ at this time, but few apps actually build workoouts based on W’ most use FTP like ours. So if you have a high W’ you also might need harder workouts. You could press the + button in our app to dial in the intensity a bit for example. I realize this is not optimum.

I don’t explain much more detail here but I talk about this exact problem in this video.

Stop Doing Hard Cycling Intervals at the Wrong Intensities

It seems like it might just be #1 that is the issue, or a combination of all 3. In general doing less intensity / stress tends to be doing too much so this is not that bad but you could try out the last VO2max from your sequence and just do a bit and see how that feels. You can just copy it and add it to your library.

[Roo]

Thanks for the detailed response. The video was very helpful.

this was the workout.

My easier workouts typically have me in zone 1 HR. Such as this one:

That said, it will still feel like the power level is calculated accurately.

[Alex]

Yes, you have a disconnect from power to HR, meaning your body does. I actually think this is lucky, but I don’t know the overall effect on performance. You should probably just increase your FTP by 15% or so, even though it is accurate this will put you in a better zone for training. If you are using ramp test for FTP you might want to try a 20 minute test some time to see if it is similar.

[Roo]

Ok, thanks for the advice!

[Roo]

I bumped my FTP up to 281 for my long ride today. Here’s the ride profile. In your experience would you say that this is in a better spot now?

repeats were at 170w. Legs felt tired by the end, cardiovascularly my breathing didn’t change much. RPE was probably about a 3, maybe 4 after my 170w repeats, but really that’s based on how my legs felt.
I’m using Jacks polarized plan, so I want to make sure I’m not pushing it to much, but also not too little. Thanks!

[Alex]

So zone 2 is best measured by breathing test in that you can hold a conversation without much trouble. Tired legs also depends on how adapted to this length of ride you are. Generally this seems fine to me, we have the belief that it’s a bit better to be a little under than over but also for “optimum” everything is “it depends.” If you normally go on 4 hour rides and a 2 hour zone 2 ride feels hard than I would say it is too hard but breathing test should be accurate enough.

[Roo]

Ok great. I’ll work from that. I now realize that it’s likely not uncommon for running heart rates and cycling heart rates to differ somewhat. Going by feel for awhile seems like a pretty good option.