[DATA] Is HR completely useless? With or without a PM?

So a week or two ago I got a PM on my bike and I've been doing a couple of rides to test out my what wattage I can hit. First of all I was hoping I could hold at least 300W for 20mins, but finding it surprisingly difficult :oops: best I've done was 277W.
I couldn't help but notice how erratic HR data is, so I decided to stick it in excel and see what comes out.

The data above is in chronological order.

As you can see there seems to be no relationship between average HR and average power, or even normalised power.
In fact, I've had two rides on consecutive days, where the ride one day #2 was faster, more power but even my max HR was lower than the AVG HR of the day before...
I've even noticed a difference in whether or not I've had a coffee, so I decided to remove it from my data screen on my cycling cpu.
So why do I still wear this thing? Because everyone else does? I'm not really sure- why do you guys wear a heart rate monitor?
Should I give it another try and see if it 'settles down'?
I couldn't help but notice how erratic HR data is, so I decided to stick it in excel and see what comes out.

The data above is in chronological order.

As you can see there seems to be no relationship between average HR and average power, or even normalised power.
In fact, I've had two rides on consecutive days, where the ride one day #2 was faster, more power but even my max HR was lower than the AVG HR of the day before...
I've even noticed a difference in whether or not I've had a coffee, so I decided to remove it from my data screen on my cycling cpu.
So why do I still wear this thing? Because everyone else does? I'm not really sure- why do you guys wear a heart rate monitor?
Should I give it another try and see if it 'settles down'?
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For me - when I'm doing structured training I monitor power and hr.
At the start of it - say - I can do 200w at 150bpm.
My plan will have me repeating some sessions again - so maybe two weeks later I'm up for it at 200w - and I can see that my HR has dropped 10bpm (or whatever). It's great for motivation and trac king how you're doing.
If my HR had escalated I'd be thinking illness or overtraining. With No HR to monitor - you'd miss this.
I use Power when following online training programs ie:- that call for 10mins at 90FTP , 45 seconds at 400% , 30mins at 100%FTPetc etc ... not much I can do about HR, it does what it wants to
I use heart rate when free riding and getting in the miles ... if I notice my average HR is at 138bpm I think .... "lazy bastid, I could be cycling harder" and up my effort
I can track TSS on TrainerRoad and SufferScore (which is a measure of HR TSS) on Strava and the relationship between them isn't very strong. The TSS tends to be between 1.2 and 1.8x the SufferScore. They tend to be closer together when the workout has long stead intervals and wider apart when the workout has lots of short sharp intervals and variations. This seems to make logical sense because when you're doing short intervals HR lag has a bigger impact.
The only thing I can say with any certainty is that when the relationship goes up to 1.8-2x or more consistently it means I really need to do an FTP test because I must have got fitter.
Where I've historically found HR useful is on endurance rides: at around 140bpm I can ride all day. Much above that and I start to struggle - so it's a useful tool in that case. I've since changed that to power because power isn't affected by adrenaline or fatigue in the same way HR is. But those measurements are all steady-state.
I do my longer efforts (I.e. 50 mile TT, runs, triathlon) based on HR as a guide and look at power afterwards.
Shorter efforts I don't look at anything as I find it can be a limiter.
When doing interval training I use power.
Steady training rides I go on feel, I.e. If it's an endurance day, am I breathing easily and able to hold conversation if I wanted?
ABCC Cycling Coach
Not everyone wears a strap. If you have power measurement, HR is at best redundant, at worst misleading.
Having said that the one time I use heart rate is long mountain climbs, I know that if it starts to creep too far above threshold then I can't sustain it. No idea whether thats just a legacy mindset but it seems to work for me.
I also think seeing your BPM is a limiter, particularly when going up steep hills.
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Yeah. That might be why, bloody segments messing up my ride
Finally I use it when doing hard intervals at constant power because I know once my hr goes above a certain number I’m about to pop. I never use this as a reason to stop though.
If you could look at the algorithms Powertap created for the Powercal, which I understand was based upon thousands of sets of actual hr and power data, it may go some way to explaining their understanding of the relationship between the two.