Power vs heart rate

I have just recently bought and started to use a powermeter.

My question is whether to use the heart rate monitor (hrm) or the powermeter (pm) to guide exercise intensity for reasonably short (30 - 45 min) and moderate level intensity workouts. If i use heart rate alone, then my required watts would be higher than planned (increase work to raise heart beat); if I use watts alone than my heart rate remains too low (e.g. in zone 1 rather than zone 2).

Basically, it seems that the issue is that the watts to heart rate calibration is based on a certain workout time. If the workout time is shorter than one of the two measures is not appropriate.

Thanks,

Eric

PS: This is my first post so I am curious to see the responses!

HR strap? I vaguely recall having one, I think it’s now a tote bag handle.

I pace by power, but keep an eye on what my HR is doing as it can give a heads up that something is not right (overheating, dehydration, illness, fatigue).

How did you determine your zones?
They should be fairly similar regardless of time barring cardiac drift.

power is what you are actually doing, the work. HR is a measurement of the response to that work.

I’d rather go by a measurement of the actual work then a response to that work if had to choose only one.

If you use the search function you will find a ton of posts on this with more reading then you probably care to do

power is what you are actually doing, the work. HR is a measurement of the response to that work.

I’d rather go by a measurement of the actual work then a response to that work if had to choose only one.

If you use the search function you will find a ton of posts on this with more reading then you probably care to do

DD, no disrespect - just want to know, Why would you do this?
If you are on a training ride or in a race and you are trying to maintain what you believe is the power output you are capable of (determined from experience and testing) and your HR starts going off the charts…wouldn’t you back off and get the HR under control so you don’t blow up. Then, after that, start comparing this to prior training / racing to determine the cause. Then maybe recaibrate your goals.
You have two sets of data, why would you ignore one? And, if you could only choose one, wouldn’t you be better off with the one that has a broader input set? The HR might be a ‘response to that work’ but that doesn’t mean you should ignore it - it doesn’t lie - it just has more input variables. HR is teh response to not only the work but a lot of things. If the HR response is ‘you’re gonna die’ then attempting to maintain a set ‘actual work’ level might not be the best strategy.

So, my response to the OP would be - on the road you usually go with HR, then, after the ride, figure out which expected measure was wrong and why. If the HR response is ‘you’re gonna die’ then attempting to maintain a set ‘actual work’ level might not be the best strategy. If the HR is up a few beats then you might push thru and see if it corrects or figure it out later (maybe see how recovery goes) what was wrong.

Thanks

While racing with power have you had your HR go off the charts?

I have not experienced that yet.

jaretj

If you are on a training ride or in a race and you are trying to maintain what you believe is the power output you are capable of (determined from experience and testing) and your HR starts going off the charts…wouldn’t you back off and get the HR under control so you don’t blow up

Lets reverse the scenario. You are in a race, your HR is way low your power is where you believe you could maintain it, would you increase your power to get your HR up?

If your HR is in the you are going to die, but your power is int he you can maintain this and live, why would you not want to live? Hr is a response to what you are actually doing. Power is what you are actually doing. It’s like driving a car and using your speedometer to know how fast you are going (power) or using the other cars around you to guesstimate how fast you are going (hr).

Your power doesn’t lie. Either you can maintain the numbers you are putting up or you can’t.

There was a thread a bit ago that discussed this. Look it up. The usual suspects chimed in, FD, AC, Rapp, myself. Use any of use to search for it.

Eric,
The best plan for using a power meter is to track both HR and power simultaneously, and to bring in percieved effort (based on your experience and fitness). While power is the actual work you’re doing, HR is, like was previously mentioned, your body’s response to the workload. Your HR response to workload can give immeasurable insight into fatigue, fitness gains or losses, hydration levels, electrolyte intake, fueling success or shortages, and the impending ‘wheels falling off.’ Like DD said, there’s lots on this subject posted already.

If you are on a training ride or in a race and you are trying to maintain what you believe is the power output you are capable of (determined from experience and testing) and your HR starts going off the charts…wouldn’t you back off and get the HR under control so you don’t blow up

Lets reverse the scenario. You are in a race, your HR is way low your power is where you believe you could maintain it, would you increase your power to get your HR up? most likely, **yes, i would increase my power. because i would not fear a problem was about to erupt. after, i would re-evaluate the paramaters i used to see which i believe was wrong. Now, i say most likely because if i suspect there may be a reason my HR is low and so increasing power might lead to a problem then i wouldn’t. i know that if i increase my power when i shouldn’t have then my HR will respond quite soon and i can back off; so i’m not too worried about that. **

If your HR is in the you are going to die, but your power is int he you can maintain this and live, why would you not want to live? My thought is that you can not have this scenario, or rather it is very unlikely. if HR says you are going to die - you are going to die, no matter what power says. It (HR) knows more about the ‘system’ as a whole then power. that doesn’t mean you shouldn’t train with power, observe power, measure improvement with power and all that good stuff but when HR says ‘slow down, something’s wrong’ ya gotta listen to it. It know more.
Hr is a response to what you are actually doing. Power is what you are actually doing. It’s like driving a car and using your speedometer to know how fast you are going (power) or using the other cars around you to guesstimate how fast you are going (hr). No, it’s like driving a car using all the gauges - speedo, tach, oil pressure, thermostat - all conected to a big red flashing light that goes off when any one is in the red zone. you can look at the speedo to drive but if the red light starts flashing you better slow down and find the cause…

Your power doesn’t lie. Either you can maintain the numbers you are putting up or you can’t. agreed.

There was a thread a bit ago that discussed this. Look it up. The usual suspects chimed in, FD, AC, Rapp, myself. Use any of use to search for it**. yes, there have been a million threads on it.

Thanks all.

Let me see if i can clarify some points raised.

Agreed that power is a measurement of actual work being done while HR is a response to the work being done. Yes, i monitor both HR and power. I also try to calibrate both power and HR to RPE.

From my limited experience, my power and HR are generally in line for longer distances/times - e.g. when I went out for a 3hr ride last weekend, i intended to keep power at circa 180w on the flats (220w on the climbs) and I broadly expected my heartbeat to start at 115ish and slowly creep up to high 130s. My HR broadly followed my expectation.

However, my issue is when I do short sessions that are not interval based - e.g. general endurance in zone 2 (130 - 145) for 45 minutes - my HR and power numbers “tell me” to pedal at different paces. E.g. last night my HR was at 115ish while pedaling at 180w. Given that i wanted a general endurance ride (not recovery, not pushing it either), should I have

  • continued to pedal at 180w since that is my expected race power eventhough my HR data would suggest that it was a recovery ride (below my estimated aerobic threshold)
  • or increased the wattage so that my heart rate would have been about 10 beats above my aerobic threshold (i.e. where i wanted my heart rate to be at)

As I did not know what to do, I went for option 2!

While racing with power have you had your HR go off the charts?

I have not experienced that yet.

jaretj

not sure what you are getting at. in 10 years of IM racing my HR has never gone anywhere i didn’t expect it to go. I find my HR amazingly consistent with my intensity level. workout after workout, week after week, year after year (even as i’ve watched my max slowly decline - i expected that too). i get the impression from posts on slowtwitch that many people find their HR to be quite varialbe.

Eric,
The best plan for using a power meter is to track both HR and power simultaneously, and to bring in perceived effort (based on your experience and fitness).

How is this best?

What if indicators conflict? What do you do during a race when HR is high but PE and Power is normal?

Eric,
The best plan for using a power meter is to track both HR and power simultaneously, and to bring in perceived effort (based on your experience and fitness).

How is this best?

What if indicators conflict? What do you do during a race when HR is high but PE and Power is normal?

if i may,
indicators don’t conflict - your expectations are not in line with the output. find out why. you shouldn’t need to choose one.

Eric,
The best plan for using a power meter is to track both HR and power simultaneously, and to bring in perceived effort (based on your experience and fitness).

How is this best?

What if indicators conflict? What do you do during a race when HR is high but PE and Power is normal?

if i may,
indicators don’t conflict - your expectations are not in line with the output. find out why. you shouldn’t need to choose one.

Ah, I see, experience will be your guide. Also known as, “I don’t actually have a systematic way of evaluating the data presented to me”

well put.

If you know your power, then at best heart rate is redundant but at worst it is misleading.

if HR says you are going to die - you are going to die, no matter what power says.

I once did a 40 km TT during which my average heart rate for the 53 min and change exceeded my normal maximal heart rate at the time, and I didn’t “die”.

It (HR) knows more about the ‘system’ as a whole then power.

All your heart rate “knows” is how fast your heart is beating. Your power, OTOH, dictates your physiological responses (in the context of the situation in question), whereas your perceived exertion tells you globally how stressful it is to generate that power/those demands. Thus, if you know your power then at best heart rate is redundant but at worst it is misleading.

it’s like driving a car using all the gauges - speedo, tach, oil pressure, thermostat - all conected to a big red flashing light that goes off when any one is in the red zone. you can look at the speedo to drive but if the red light starts flashing you better slow down and find the cause…

Bad analogy. A better one would that using a heart rate monitor is like trying to drive your car while only looking at the tachometer, whereas using your perceived exertion actually represents using all of your instruments as you describe.

What do you do during a race when HR is high but PE and Power is normal?

I chose to push on anyway, and:

  1. met my goal (barely!) of running 30 km in under 2 h; and

  2. made the podium again in the TT at master nationals (almost beating Carl Sundquist in the process).

Neither 1 nor 2 would have happened if I had paid attention to my heart rate and decided to slow down.

Thanks all.

Let me see if i can clarify some points raised.

Agreed that power is a measurement of actual work being done while HR is a response to the work being done. Yes, i monitor both HR and power. I also try to calibrate both power and HR to RPE.

From my limited experience, my power and HR are generally in line for longer distances/times - e.g. when I went out for a 3hr ride last weekend, i intended to keep power at circa 180w on the flats (220w on the climbs) and I broadly expected my heartbeat to start at 115ish and slowly creep up to high 130s. My HR broadly followed my expectation.

However, my issue is when I do short sessions that are not interval based - e.g. general endurance in zone 2 (130 - 145) for 45 minutes - my HR and power numbers “tell me” to pedal at different paces. E.g. last night my HR was at 115ish while pedaling at 180w. Given that i wanted a general endurance ride (not recovery, not pushing it either), should I have

  • continued to pedal at 180w since that is my expected race power eventhough my HR data would suggest that it was a recovery ride (below my estimated aerobic threshold)
  • or increased the wattage so that my heart rate would have been about 10 beats above my aerobic threshold (i.e. where i wanted my heart rate to be at)

As I did not know what to do, I went for option 2!

Given your stated goal, you should have just maintained that 180 W power output. By increasing the exercise intensity to raise your heart rate into some particular range, you trained harder than you intended.

(Note that I’m ruling out a true training-induced reduction in heart rate, since based on your weekend data this appears to be a case of residual fatigue suppressing your heart rate response to exercise at a constant intensity.)