Heart Rate Zones

nanastaci2020
nanastaci2020 Posts: 1,072 Member
edited April 2021 in Fitness and Exercise
How important are heart rate zones for cardio/heart health?

I do cardio for the purpose of burning additional calories. (Because as a sedentary female in a healthy weight range, my TDEE is dreadfully low if I don't make the effort to move more!)

But I also do cardio because I know it is good for heart, lung health and overall fitness ability.

I'm 46, female, 5'5", and low 130's. I'm relatively healthy - good BP, cholesterol, etc. According to my Fitbit data my RHR is around 60-61. My BP tends to be low normal.

When I walk (not cardio level) at my desk 2.5 mph, my avg bpm is around 97.
When I walk (light cardio) around 3.25-3.5 mph, my avg bpm is a tiny bit higher, around 102-105.
When I walk (moderate cardio) around 3.75-4.0 mph, my avg bpm is about 113-115.

I can push my bpm higher by running, but I'm out of practice and can only run brief distances. And I'm not sure I want to work on running more at present.

I also average 115 bpm or so when I walk outside for an extended period of time, with moderate uphill/downhill terrain, around 3.5 mph.

Mainly I'm wondering if I should be working harder, pushing to go faster when aiming for cardio to get my heart rate higher.

What has brought this to mind? A Fitbit Bingo challenge where I fill in 'spaces' based on steps, distance, and 'active minutes'. Fitbit lists my 'fat burn zone' at 106+, 'cardio zone' at 129+ and "peak zone" at 157+. I'm not earning many active minutes but I'm not sure if these 'zones' even matter.

Replies

  • Lietchi
    Lietchi Posts: 6,033 Member
    edited April 2021
    I'm not a huge expert on heart rate zones, but I do know that these zones/heart rates you mention don't mean much if you don't have an idea of your true max heart rate (not using the generic formula based on age). Based on your true max heart rate, your zones might be very different!

    In absence of a true max heart rate, you might be better off using a perceived rate of exertion to judge how hard your workout is.
  • spiriteagle99
    spiriteagle99 Posts: 3,668 Member
    For good health, you need 45 minutes of moderate intensity exercise, 5 days a week. High intensity isn't necessary unless you are trying to improve your VO2max for a sport.
  • NorthCascades
    NorthCascades Posts: 10,970 Member
    Zones are an approximation, and they have blurry edges. It isn't the case that having an HR of 157 is great and 156 isn't.

    With that said:

    You should exercise at a variety of intensities, including Z4 and Z5, for health. Different intensities work different systems in your body and since you said your goal is heart and lung health, you want a good mix. It's like the food pyramid, most of your exercise should be lower intensity.

    Running can peg your HR but you can do the same thing on a bike, swimming, skiing cross country, and a lot of other ways. Might even find one you enjoy a lot. πŸ™‚
  • NorthCascades
    NorthCascades Posts: 10,970 Member
    Lietchi wrote: Β»
    I'm not a huge expert on heart rate zones, but I do know that these zones/heart rates you mention don't mean much if you don't have an idea of your true max heart rate (not using the generic formula based on age). Based on your true max heart rate, your zones might be very different!

    In absence of a true max heart rate, you might be better off using a perceived rate of exertion to judge how hard your workout is.

    This isn't the case at all. Your zones work much much better if you don't use your maximum heart rate. There's really nothing that special about mHR, and 80% mHR is pretty meaningless. Again, these zones are an approximation, and basing them on % max will get most people in the right ballpark.

    What's important is your threshold (LTHR). This is biologically important in the context of cardiovascular exercise, perceived exertion, and health. If you're exercising for fitness or CV health, LTHR is the best way to use heart rate zones to guide your exercise and to evaluate the quality/impact of a workout. Most people find that when they switch to basing their zones in LTHR, the zones suddenly make sense and line up with perceived exertion.

    Here's more info from a highly acclaimed sports scientist who's written several books on the subject:

    https://joefrielsblog.com/a-quick-guide-to-setting-zone/

    Hope this helps. πŸ™‚
  • Lietchi
    Lietchi Posts: 6,033 Member
    Lietchi wrote: Β»
    I'm not a huge expert on heart rate zones, but I do know that these zones/heart rates you mention don't mean much if you don't have an idea of your true max heart rate (not using the generic formula based on age). Based on your true max heart rate, your zones might be very different!

    In absence of a true max heart rate, you might be better off using a perceived rate of exertion to judge how hard your workout is.

    This isn't the case at all. Your zones work much much better if you don't use your maximum heart rate. There's really nothing that special about mHR, and 80% mHR is pretty meaningless. Again, these zones are an approximation, and basing them on % max will get most people in the right ballpark.

    What's important is your threshold (LTHR). This is biologically important in the context of cardiovascular exercise, perceived exertion, and health. If you're exercising for fitness or CV health, LTHR is the best way to use heart rate zones to guide your exercise and to evaluate the quality/impact of a workout. Most people find that when they switch to basing their zones in LTHR, the zones suddenly make sense and line up with perceived exertion.

    Here's more info from a highly acclaimed sports scientist who's written several books on the subject:

    https://joefrielsblog.com/a-quick-guide-to-setting-zone/

    Hope this helps. πŸ™‚

    Might have to read this in depth later, but already in step 1 he states "Do not use 220 minus your age to find max heart rate as this is as likely to be wrong as right." which is one of the points I was making. I'm presuming most trackers like Fitbit use this formula to determine the heart rate zones (unless the user has entered a max heart rate manually, or has entered zones manually).

    As for the rest, more reading required apparently, if I ever want to use heart rate zones myself (or ever give advice about them πŸ˜†)
  • cwolfman13
    cwolfman13 Posts: 41,879 Member
    Zones are an approximation, and they have blurry edges. It isn't the case that having an HR of 157 is great and 156 isn't.

    With that said:

    You should exercise at a variety of intensities, including Z4 and Z5, for health. Different intensities work different systems in your body and since you said your goal is heart and lung health, you want a good mix. It's like the food pyramid, most of your exercise should be lower intensity.

    Running can peg your HR but you can do the same thing on a bike, swimming, skiing cross country, and a lot of other ways. Might even find one you enjoy a lot. πŸ™‚

    Pretty much this ^^^
  • nanastaci2020
    nanastaci2020 Posts: 1,072 Member
    Looking at the 'info' section on my Fitbit under HR, it does use the 220-age = max and then percentages of max to determine zones. There is an option to customize the max.

    I appreciate the feedback, which is why I posted here. I was sure I'd get some info and outlets to research more.

    I like running and that is my best outlet for higher HR levels, but need to work up gradually to be able to go for more than a few 30-60 second sprints. (Going too far/too fast can lead to damage and that is NOT my goal as I do have potentially problematic knees from an auto accident years ago.) Will perhaps put focus into that in the coming weeks. I don't have an outlet at present for swimming or skiing, and I detest biking. Running became my project of choice after once thinking I could never run, after breaking my legs in a car accident. But I can, if I work up to it methodically. My best is running about the first 10 miles of a 1/2 marathon a few years ago. (Which made my Hubs mad at me, as he was quite lax on his training and he could not run more than the first 4-5 miles.)
  • heybales
    heybales Posts: 18,842 Member
    Agree that variety of zones, if they won't cause other harm (and some can mean intensity is high enough to hurt, say, knees), is useful for everything life.
    From powering up some stairs without fainting at the top, to emergency run for some reason to help someone.

    I'd suggest notice in a run at what point after 3-5 min you are at top of aerobic zone, probably handle talking in 3-4 word sentences only, then must breath.

    Call that 85% of HRmax, and then set that Fitbit figure to match instead of their default 220-age.
    Then create a custom zone (it used to be when you made custom HRmax figure the 3 zones was hosed up, but maybe not anymore) if needed for the 70-85%.
    Now you know going over is hitting what they call "Peak", and below that zone would be Active Recovery if still sore from prior day intense workout.

    I like the LT method too, but that is really for training reasons if followed, and I haven't been lately and been just fine based on perceived when running.