Cycling UK Forum

A couple of months ago I got a heart rate monitor (in a Garmin watch). I've left my "Max. Heart Rate" as set by default by Garmin. Initially it was 156 (I'm age 66/67) which made sense. As it's part of the watch it's recording heart rate all the time, not just for activities.

But in my activities I've been seeing occasional heart rates above this max. So I wondered about changing the max. but notice that Garmin has adjusted my max heart rate to 173. (Also all the "Zones" left at the Garmin defaults).

So not urgent (and no concerns) but:

1. Should the Max. heart rate be the max you ever see or should it be the max. sustained for a period of time or set it to the 220-age (or whatever the equation is)?

2. In relation to Garmin Connect: I've never set the max rate but it's set to a value with no "Auto" option. Is it normal Garmin behaviour to adjust the max heart rate according to what it sees/records (and it distinguishes between brief peak/arrhythmia and sustained for a short period, etc.)

What I have noticed (not something I monitor but just something I happen to have noticed is that the Garmin 1040 does Active Calorie estimations for activities. Pre the heart monitoring Active (NOT Net) Calories was around 30/mile. If I sent the heart rate sensor to the 1040 the calorie estimate initially dropped to 22/mile but gradually has decreased further to maybe 17/mile. I assume the gradual drop might be related to the increase in it's Max Heart rate use (ie affecting how much of each ride is in each zone as same activity means lower HR Zones as max rate increases.

I appreciate the calorie estimate is a bit of a joke/toy/wild guess. In fact I've assumed quite a lot of the stats the Garmin now generates are more of a "wild guess/toy" than any real measure (eg fitness age, training readiness, etc.).

Asking only out of interest, no concernes about information now being presented through this thing.

Ian

I can’t comment at all about anything Garmin.
With my Apple Watch my cycling is always 4 cal/ minute, playing badminton is always 5 cals/ minute.
Max HR playing badminton is usually 134, Max HR cycling is never above 124 At some point a spike registered around 170 and if I were to allow AW to set the zones then it uses this spike and makes zones useless. I’ve edited my zones to a max of 134 and a min of 42 and all feels right.

Psamathe wrote: ↑10 Mar 2024, 1:18pm A couple of months ago I got a heart rate monitor (in a Garmin watch). I've left my "Max. Heart Rate" as set by default by Garmin. Initially it was 156 (I'm age 66/67) which made sense.

1. Should the Max. heart rate be the max you ever see or should it be the max. sustained for a period of time or set it to the 220-age

Just been reviewing mine, 156 max heart rate seems very high for a 66/67 age. Sure the NHS would recommend around 116 bpm for a sustained workout (Nb. NHS recommending no more than 75% of maximum HR for sustained exercise)

After a couple of slack years (Nb averaging 180 miles weekly last summer), have got back to gym based, cardio sessions. Couldn't help note that I was habitually working out at the max heart rate, actually designated for me, just over a quarter of a century ago. I must be about a quarter of a century older, with presumably a lower recommended max heart rate ?

And having always presumed that working out harder & harder was better, has been notable that having been in multiple emergency ambulance / acute units over the past five years (Nb. Not heart issues), ,medical concern at my oversized heart muscle has been mentioned in internal letters / memo's, on any number of occasions. Too much exercise > max HRM, must be a medical concern ?

Firstly, I've always interpreted the theoretical max heart rate as the rate a healthy human heart should be able to attain rather than a limiting maximum rate that shouldn't be exceeded.

Secondly, different authorities use different formulae to derive the max, e.g.

a. Classical: 220-age of subject. I believe this comes from a couple of cardiologists Polar consulted back when the world was merely middle-aged, and is the one modern medics will use to castigate you for exceeding.

b. Precise for subjects over 40: 207 - (age x 0.7)

c. Very precise for the older subject: 211 - (age x 0.64)

Can't remember the sources for the last two: I did some Googling when I was writing a program to analyse GPX files around 10 years ago and they're what I found and incorporated. In my case, my max theoretical rates from the above are

a: 143 bpm;
b: 153 bpm;
c: 162 bpm.

My max on yesterday's ride was 159 so I suspect formula c is probably the most representative. Curiously enough, this instance occurred while I was having a minor altercation with a cow in a car so I suppose adrenalin has more effect than exercise alone. YMMV

Thanks and to clarify (as I have no expertise on this):

When I first setup the watch using Google (on reputable sites) most said max. HR 220-age which for me was 220-67=153. The Garmin had defaulted to 156 so I left it there.

It's only when I checked that I noticed it is now 173. But just checked and it also has enabled auto max detection. To complicate it more there is a max HR and a Lactate Threshold.

I've only noticed the above 156 a couple of times and highest ever seen was 164 (I think). Looking at my recorded cycling & walking and the majority of most is Zone 2 some Zone 3. When I do gym stuff it's more Zone 3 some Zone 4 and some Zone 2.

But I do have some chronic recurrent infection which periodically flares-up with quite a few symptoms; a relapse lasts a couple of weeks part of which will also include heart arrhythmia - and I'm wondering if the Garmin high (173) detected reading might be such an arrhythmia/palpitations time.

I have no idea if going above your max is good or bad for your heart, I just go for a ride or do some strength exercises or go for a walk. From the auto detect it does seem that the watch has been recording what it considers higher heart rates (I assume more than brief "blips").

I don't actually use the HR nor the zones, just something I don't understand and I'd like to understand a bit more.

Edit: nb I believe my resting HR is fine, today 48 but generally (av. for last 4 weeks) 52bpm.

Ian

Having done a couple of Bruce tests at the hospital, I don't think exercise alone would get your HR anywhere near maximum without you noticing the effort. You'd more than just notice.

I've done cardiac stress tests every year since 2007, on a stationary bike and increasing in resistance by 50W every 2 minutes. The rules here don't allow a cardiologist to take you over the Holy Polar limit, and the last couple I did he called it off a bit below it, which I found a bit boring. IME when you get up to your max output wattage your legs complaining take all your attention.

Funny thing: at the end of the test he always asked me why I stopped pedalling, was it lack of breath or sore legs. But it was never me who stopped the test, it was him that said OK, enough. Possibly as cyclists we're used to sore legs and can ignore them.

Audax67 wrote: ↑10 Mar 2024, 2:26pm Firstly, I've always interpreted the theoretical max heart rate as the rate a healthy human heart should be able to attain rather than a limiting maximum rate that shouldn't be exceeded.

Secondly, different authorities use different formulae to derive the max, e.g.

a. Classical: 220-age of subject. I believe this comes from a couple of cardiologists Polar consulted back when the world was merely middle-aged, and is the one modern medics will use to castigate you for exceeding.

b. Precise for subjects over 40: 207 - (age x 0.7)

c. Very precise for the older subject: 211 - (age x 0.64)

Can't remember the sources for the last two: I did some Googling when I was writing a program to analyse GPX files around 10 years ago and they're what I found and incorporated. In my case, my max theoretical rates from the above are

a: 143 bpm;
b: 153 bpm;
c: 162 bpm.

My max on yesterday's ride was 159 so I suspect formula c is probably the most representative. Curiously enough, this instance occurred while I was having a minor altercation with a cow in a car so I suppose adrenalin has more effect than exercise alone. YMMV

This prompted me to do some online searches and I found:

Age-predicted maximal heart rate revisited

from https://pubmed.ncbi.nlm.nih.gov/11153730/ (Tanaka) which suggests the 208-(age*0.7)

From bicycling.com an article "Understand What’s Fact and Fiction When It Comes to Calculating Max Heart Rate" https://www.bicycling.com/training/a200 ... hs-busted/ (no idea about who they are but there are links to some sources).

And I have no idea about this site (so I'd normally ignore it purely because I don't know about them) but they give a few other calculations (incl. different formulae for women) https://www.verywellfit.com/maximum-heart-rate-1231221. I'm always over cautious about medical stuff on internet from sites where I don't know their reputation.

Thanks everyone for info.

Ian

Just been reviewing mine, 156 max heart rate seems very high for a 66/67 age.

Seems about right as a starting bid for maximum to me. The rough approximation of 220-age for the OP gets to 153 or 154.

Maximum is maximum, so the NHS guideline for sustained exercise is bound to be lower, and it looks to me as if they’ve set it fairly conservatively to account for a range of fitness levels.

I’m a couple of years younger, and I know that my practical maximum is somewhere c173, which I hit periodically on steep and rough climbs, but as I mentioned in other similar threads the cardio chap (a keen cyclist of the same age) advised me “not to thrash away over 90%HR for long periods”. He was relaxed about the odd stiff climb though.

If I go on a longish ride and finish feeling I’ve had good exercise but not whacked myself, I can almost guarantee that the average HR will be 120-130, with short bursts heading towards maximum, and the rest probably half the time at 70-80% (which corresponds to the borderlands between “moderate” and “vigorous” in NHS terms), and a quarter each at 80-90% and below 70%. I don’t do it deliberately, but that pattern comes up time and again if I remember to wear the monitor.

Psamathe wrote: ↑10 Mar 2024, 3:47pm This prompted me to do some online searches and I found:

Age-predicted maximal heart rate revisited

from https://pubmed.ncbi.nlm.nih.gov/11153730/ (Tanaka) which suggests the 208-(age*0.7)

From bicycling.com an article "Understand What’s Fact and Fiction When It Comes to Calculating Max Heart Rate" https://www.bicycling.com/training/a200 ... hs-busted/ (no idea about who they are but there are links to some sources).

And I have no idea about this site (so I'd normally ignore it purely because I don't know about them) but they give a few other calculations (incl. different formulae for women) https://www.verywellfit.com/maximum-heart-rate-1231221. I'm always over cautious about medical stuff on internet from sites where I don't know their reputation.

The NIH site looks familiar, could have been where I got it. And the "Factors that affect MHR" section on the other site talks sense - good find.

One gloomy realisation is that while MHR decreases with age, the power and therefore BPM required to get up any given climb seems to remain roughly the same, so that eventually the average heart rate you need for any given performance will be greater than your theoretical max.
E.g. when I was 70 I did a particular col with an average BPM of 141, which is 98.6% of my max BPM these days (according to Polar). OK, there are a couple of holes in that, e.g. I could always go up it more slowly (or could I? I was doing 8 kph in the steep bits and at 6 kph I'm all over the road) or I could lighten the bike, but gains would be marginal so I believe my hypothesis is pretty well correct. This is why I ride with a motor these days.

Nearholmer wrote: ↑10 Mar 2024, 5:07pm

Just been reviewing mine, 156 max heart rate seems very high for a 66/67 age.

Seems about right as a starting bid for maximum to me. The rough approximation of 220-age for the OP gets to 153 or 154.

Maximum is maximum, so the NHS guideline for sustained exercise is bound to be lower, and it looks to me as if they’ve set it fairly conservatively to account for a range of fitness levels.

Fair enough. What you basing that assessment on? I presume you can explain why other medical sources set a safe heart rate for sustained exercise, at a lower level than the NHS. Are such simply more conservative then the NHS?

gbnz wrote: ↑10 Mar 2024, 5:22pm

Nearholmer wrote: ↑10 Mar 2024, 5:07pm

Just been reviewing mine, 156 max heart rate seems very high for a 66/67 age.

Seems about right as a starting bid for maximum to me. The rough approximation of 220-age for the OP gets to 153 or 154.

Maximum is maximum, so the NHS guideline for sustained exercise is bound to be lower, and it looks to me as if they’ve set it fairly conservatively to account for a range of fitness levels.

Fair enough. What you basing that assessment on? I presume you can explain why other medical sources set a safe heart rate for sustained exercise, at a lower level than the NHS. Are such simply more conservative then the NHS?

The HR you can sustain depends on the time you're sustaining it for, that's why Marathons aren't run at the same speed as a 100m sprint. Maximum HR is the absolute maximum you can achieve just for the few seconds it takes to measure it.

I’m not sure whether the NHS publish the logic that led them to select what I think is c75%HR for sustained (don’t they actually call it “moderate”?) exercise in an accessible form, but the US-CDC do (a very long and detailed report from 2008, which I’ll link to if I can find it again) and they pitch in very much the same area for “moderate”, and it’s clear that they’re doing that with a population-wide view of benefits and risks.

I'd ignore any formula that claims to provide your HR-max. These are based on population data -- averages -- and don't really apply to individuals. I'm 69 and my HR-max is about 172.

HR-max is the highest your heart can get to (excluding rhythm disorders), it doesn't need to be "sustained" for any length of time. But as HR always lags a bit behind power output, you have to do a bit of a sustained effort to get there. A sprint won't do it. You can find a variety of suggestions online; they mostly involve a repeated, short-ish maximum aerobic effort.

I don't know about Garmin, but Strava estimates of kcal burned are wildly inaccurate -- sometimes by a factor of x2. To get a rough but reasonable estimate needs a power meter. 100W for an hour burns roughly 360 kcal. I generally burn 450-500 kcal / hr, which means about 30-40 kcal / mile.

I'm not sure if there's clear evidence that exercising up to HR-max carries a risk of cardiac events, but I haven't looked at the literature recently. High-intensity intervals are often recommended for older individuals (Google CERG Norway for more on this). You're unlikely to be able to do "sustained" exercise at much above 75-80% of HR-max unless you're already fit.

ed.lazda wrote: ↑11 Mar 2024, 9:05am I'd ignore any formula that claims to provide your HR-max. These are based on population data -- averages -- and don't really apply to individuals. I'm 69 and my HR-max is about 172.

Certainly: they're ballpark figures.

I'm not sure if there's clear evidence that exercising up to HR-max carries a risk of cardiac events

I'm not sure about causing - in fact, I'd doubt it - but it can be pretty good at showing up defects, particularly in cold weather. My first heart attack was in January 2016: my log entry reads:

Tootle to see if heart works. It does, HRM doesn't but oesophagitis fierce.

ETA: EEEJIT. It wasn't oesophagitis, it was a heart attack.

It was 4°C at the time. Turned out to be a blocked right marginal coronary artery.

ETA: re high heart rate causing cardiac events, there's always the possibility that a bit of plaque might be dislodged and block something. Depends on how much plaque you have, and you can't really know that without targeted examinations.