I am trying to figure out some weird mismatches between my heart rate and power zones. Essentially, it seems like my zone 2 power often corresponds to zone 1 HR, and I’m able to do silly-long “threshold” rides by power zones, which makes it seem that my FTP should be higher compared to threshold HR. However, almost every time I do a threshold test (or when I was racing, after almost every race), I get a notification that my threshold HR should be higher. I seldom hit my target power at the same time.
I also frequently get power spike detection notes from Intervals when I do a sprint workout, which seems to indicate that my FTP should be higher… but I am veeery rarely able to complete a VO2 Max workout with intervals in the 2-4min range, and certainly don’t see any progression in those during the course of a training block (eg. from Sustainable Training – Spare Cycles).
Here’s some background data:
40 year old male
18ish years of cycling, a bit more of running. I did no endurance sports until my 20s. First mostly focused on CX and XC racing, bit of crits, then gradually getting longer and more road/gravel focused.
Fairly inconsistent training. I tend to run into physical and mental health issues with heavier training loads. Last year was my most consistent ever and I averaged about 6 hours a week. I registered my longest ride ever (216km / 7:22, which Intervals classified as Threshold based on power zones), best FTP (259w) and best 5-second power (1178w). The lowest I’ve ever tested my FTP was around 240w, so I’m not seeing much improvement with my “training”.
I’ve been using essentially the same HR zones since I first started using a HR monitor around 15 years ago, not (just) because of laziness, but because they’ve stayed quite consistent with tests and perceived exertion.
My suggested threshold HR seems “too high” especially for my age, but that’s so individual that I don’t know if it’s actionable (yesterday Intervals suggested I should raise threshold HR to 170bpm, and I’ve 1-2 “nice ride” emails a month this year suggesting values as high as 174; I did two 5km runs last year where my HR averaged 180 for 19:33 and 20:35, respectively).
Aerobic decoupling is all over the place. 20-30% of rides have negative decoupling. I’ve had 3-hour Pyramidal rides with -8% decoupling, and similar length base rides with +20%.
Zones pasted below for reference. My previous 42 days have been a bit whacky because we had our first child at the end of July
The only thing I can think of would be to nudge my Z1/2 power zones higher, compress 3/4, keep FTP the same, and turn off power spike detection. That’s addressing the numbers discrepancies, but are there any underlying physical issues that I should address or look deeper into?
The HR zones are based on Max HR. I suspect you have that set too high. Take a look back at some really hard efforts and see what the highest numbers are over a couple different sessions.
Interesting, I guess I didn’t look close enough at intervals.icu. My HR settings only have 5 zones, because HR isn’t all that valuable for zones 6 and 7.
@fallingcow has his HR zones very tightly defined, and that may also be part of the problem?
@AvidCyclist I did not update my zones after those rides, as it seems like it would make the issue worse (zone 1/2 would be higher HR for same power). I could definitely try though!
@fabric5000 As noted, zones are set based on my threshold, not max. However, I have recorded a max of 200bpm this year and numerous rides with maxes in the 190s.
@WindWarrior Interesting, the explanation for power spike correction mentions that it’s based on FTP: “Power spikes are detected by comparing your power output to what you should be capable of based on the power duration curve for your FTP… Also consider raising your FTP if many spurious spikes are being detected.”
I’m not an expert so I just took that as gospel, but maybe those of us with more punchy power curves should turn it off or set the threshold high?
Also re: @WindWarrior I could switch to a 6-zone model like yours to maybe help. The HR percentages in your model seem pretty low - the upper range of endurance is on the lower side of my current Z2. However, it does match up my avg power to HR a bit better on many rides (norm. power is of course way different, as is time in zone). I have some exceptions (4h50m with an average of 151bpm, 4h38m at 165bpm average ) but those were rather intense rides and probably not “healthy” . I do think however that if I used those zones I’d have even rides classified as tempo for power and recovery/endurance for HR (based on zones rather than average).
There’s quite a number of users which have it set to a high number. Mine is at 80% because with the standard value, there was clipping for sprinting power.
If your Power Meter is reliable, this setting is actually not needed. But there are some Power Meters spitting out spurious high values.
Back in 2016 I started using Friel HR zones, which I believe are the default for Intervals. A couple years ago I switched to Coggan zones, however I don’t really use those.
Instead I have “field based zones” and a custom HR chart so I can eyeball HR:
1 hour easy - HR mostly below the lower grey band inside the blue “HR zone2”
Do you use an intervals preset for hr-zones? Those never matched mine at all, especially Joe friel’s zones didn’t. My cycling HR zone 1/2 boundary is at 72% LTHR. (Confirmed by a lab test). When I’m fatigued, it’s even lower.
So personally I have to look at power more that heart rate. I had a small race this year that I did not taper for, kinda anti-tapered with a 150km ride the day before and my HR during the (cold and rainy) bike-leg was 116 bpm while power average was in tempo/ treshold.
My HR zones look more like the other one who posted their zones. Lower tempo HR boundary at 85% LTHR.
It’s a good point, in the end, these don’t matter too much, I just ride bikes for fun. What is frustrating for me is that if I train with power, I feel underworked in zone 2 and can’t hit targets in zone 4+. I could just ignore all the numbers and ride my bike, but I do enjoy training and getting faster.
Interesting, this is kind of what I suspect is the case for me (zones don’t align with standard models). I don’t really want to pay for a lab test but maybe that’s the best way forward although as @ivegotabike says, maybe this doesn’t actually matter.
I did a ride the other day where I tried to ignore the numbers and go by feel in zone 2. HR was mostly in Z1, with a bit of zone 2, and zero time at higher zones. Power was mostly Z2, with some 1, 3 and 4. Intervals classified it as a threshold ride using power. Another potential theory is that I’m really bad at steady state power, so my power spikes into Z3+, and my HR doesn’t have time to follow. Then power goes back into Z2, and HR drops back to Z1.
It’s a lot of info to work through at this point but you say Z2 power (75% of FTP) feels too easy but you can’t complete a 5x5 minute VO2 workout at 115-120% FTP? That would be another trial and error approach to find out what your 9/10 RPE Power for a 5x5 minute workout is – and estimate FTP from that 5 minute effort. Best done on zwift I guess.
How many hours per week do you ride and how does your full power curve look like? There’s a big gap between 5 min and 60min in the one you posted.
Your power meter is calibrated btw? Also good to know if a second power meter like a smart trainer agrees to your first power meter.
It also depends on your (recent) training history and objectives.
Many riders coming out of a decent duration of base training have a tough time when they come back to higher intensity workouts.
That is to be expected. No one should expect their first VO2 workout of the year to be a perfectly executed example 6x 5’ @125%. But, with a plan to get there and careful execution of less demanding VO2 workouts on the way, they could get there in a few weeks.
On a regime of 6 hours per week (as per your first post), there will a lot of gaps in your capability and mismatches with various theories that can be analysed until the cows come home but, the reality is, that they are only properly addressable by spending more time on the bike.
56 yo male here with HR max of 197 (I hit it a few weeks ago, but usually only once or twice a year. I regularly hit 190 and my LTHR is ~180).
My power zones and HR zones have never aligned properly. I looked it up on the internet and found an article on TrainerRoad site where it said that some people’s zones never align well between HR and Power.
So I’ve accepted it - and as someone else said - at the end of the day it doesn’t matter.
Power zones are more reliable for training purposes anyway.
A metric that will give some insight is Decoupling found on the Power page. This is performed by riding at a steady effort and heart rate in Zone 2 and is useful for ann Endurance, Base evaluation. A two hour measuring minimum period is best though a one hour period will yield decent results. Best is under 5%.
Also, Efficiency testing is another which can be performed frequently and more easily. Joe Friel says he takes Lactate Threshold Heart rate and subtracts 30 for a rough estimate of one’s’ Aerobic Threshold HR, upper Zone 1 or lower Zone 2. The test should be done over the same course at the same intensity for the period of time someone I interested in while keeping HR constant. Compare over time.
@alex_cycles I believe that too. We can get too tied up in metrics. As long as the work is getting put in, there are results. Everyone’s engine is different.
Wow, thanks for all the details in your thoughtful responses! Yes, power meter is calibrated, and I get the same results from two different crank-based power meters (and those aligned with my smart trainer when I had one). I’ve used 4 different HR monitors, but all are wrist or bicep-based - unfortunately do not currently have a working chest strap.
I’ll try out those Coggan zones you mentioned, thank you! At first glance it does seem a bit low (tempo begins at 145, vs. 150-156 in my current zones) but might be worth using as a starting point and putting my finger on the scale a bit.
) but those were rather intense rides and probably not “healthy” 
. I do think however that if I used those zones I’d have even rides classified as tempo for power and recovery/endurance for HR (based on zones rather than average).
