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Ken Germaine

Hey Joe, Great comments, I can vouch for them, being an n=1 cyclist w HRM for 20yrs and PowerTap for 6yrs. I use those characteristics as a measure of fitness & detraining. before PT I learned to use the HRM & effort together to gauge effort for training. Races are races & the HRM is only an indication of freshness & fatigue. Thanks for teh great blog!! Ken


Good post and very logical. if the Stroke Volumes goes up, less beat required. Make sense.

However, does it means the amount of blood going around is the same? and it means the same O2Max?

I often heard VO2Max is not gonna change a lot but still some improvements are seen from race seasons from off seasons. Is this simply considered SV increment is greater than MHR decrease?

Tim Shaffer

This is really interesting. I've definitely noticed this myself over the past year. I train with a power meter in addition to heart rate monitor. I increased my training load and intensity this year, and I noticed that my power numbers are consistently higher, but my heart rate numbers are slightly lower. No matter how hard I push this year, I have yet to hit the max heart rate that I could last year, even though I'm putting out more power now.


this is a very interesting subject, i find my hr is lower when i have been training heavy, can be 5-15bpm lower. for this reason it seems very hard to keep within the prescribed training zones. precieved exertion helps but it still is very frustrating when doing level 4 work as i start to question if i should continue the workout or just go home and take a couple days rest. any futher discussion on this topic would be helpful.


great topic.. i find exercising hr lower by as much as 5-15 bpm after heavy training or racing, such as in the build period after 2-3 days rest betweeen z4 efforts. it makes using hr training zones a little frustrating. not sure if i should continue the effort or just go home and take a day or two rest.


Just can confirm from personal experience, that after my recuperation period in october the heart rate due to "playing" mtb on small hills rides goes easily over 185, even to 189. But now, during racing season it goes barely to 182... This happens every year over and over again...

By the way, I see the same evolution with my lactate threshold, goes from 175 in very early base to 168 in race season.


Hello Joe,

Thanks for the post. I don't have a power meter, and I use my HR meter device as an aid in my workouts, and indeed I've noticed a decrease in my HRM over the year.
And, as you suggest in your cycling training books, I follow the lactate threshold HR zones.
But, what I have understood is that I might expect a raise in this value (LT) at the end of the Base period (if it has been a good training season).
If I am right, this should be very close to the HRM variations commented in the post.
So... Is this reasoning right?
Regards from Chile,


Joe Friel

Roberto--Changes in LTHR seem to be very tiny in athletes who remain in even decent condition over the course of a season. But I've found no research to confirm this. just my observation.


After spending 20+ years doing no more than commuting to work by bike, I've spent the past couple of years training for racing (without doing much racing). My fitness level has soared. That said, I noticed something different about MHR. Eighteen months ago, I never saw my HR get above 172. A year later, I was occasionally seeing my HR up near 185. I think I've seen the effect discussed in your post, as I currently never see much beyond 177. But it does appear to me that as my fitness significantly improved over the first year+ of training, my MHR increased.

Göran Gramby

Fascinating. I have always been told that max heart rate cannot be changed by training. When I started running again 2 years ago i tested my max heart rate to 192 bpm (I am 46). Today I am considerably better trained and cannot go over 185 bpm. My treshold pulse is around 172.
Just one philosphical question. Is there a max Power (as in Watt) you can get out of your heart? I.e. when the heart gets more effective the max available bpm goes down. I realise this is a very simplified way of looking at things, but still.

Best Regards from Sweden


Joe Friel

Göran Gramby--As stroke volume increases, bpm decreases.


Joe - Your reply to Roberto states that you have observed very little change in LTHR over the course of a season for athletes in descent condition, but for a beginner, or someone returning to training, could one expect the LTHR to increase over time, then level out once at that optimal level, or would you opine that the reason it went up was that the out of shape athlete just didn't know how to push one's self hard enough to get an accurate LTHR reading?

Joe Friel

Hi Scott--It could be either. I really don't know. Certainly as fitness changes LTHR will increase as a % of VO2max. But novices will often not get a good VO2max result because they are unable/unwilling to push themselves that hard. So both may come into play.

Richard La China (lachina)

A couple of weeks ago, I was asked to participate in a Vo2 max and Lactate Threshold test by a small group of undergraduate student researchers at San Diego State University (SDSU). It sounded like a great opportunity for me further my investigation, and because it was free, I couldn’t say no...


Richard La China


Andrew walker

I have recently (3 weeks) started training.
Yesterday I consistently wound up the pace over a mile and a half finishing with an all out sprint uphill. I measured my MHR as 188. However as I am still relatively unfit I was unable to ontinue that sprint for as long as I would had I been fitter. Indeed after a few seconds I attempted a second sprint and had to abandon it.

My belief is that I have not yet measured my true MHR and it will be higher than measured so in future measurements it will rise. Yet your article states it will lower as I get fitter.(Is this only for trained athletes?)

What do you expect me to see in further tests?


Hi, I ve been doing Ironman distance training for over a decade and I notice that my max heart rate now tops out at 165bpm.. not sure if I'm getting lazy or its a function of being healthy?

Joe Friel

Tim - Don't sweat it. It's a non-issue.

Doug Fargher

I have found that my max heart rate seems to be increasing from 168 to 172 but I am breathing less hard. I am finding the exercise easier as breathing rate seems fro me to be the limiter. I do not see much reference to breathing rate but it must also play a part in overall performance. Slower breathing with faster heartrate may be similar to faster breathing with slower heart rate. I notice my periods of performance improvements ( quicker times ) seem to coincide with the slower breathing periods. Comments

Joe Friel

Doug F--As fitness improves improves, efficiency improves. If you don't have a way of comparing output and input to measure efficiency (you didn't mention what your sport was so can't suggest anything here), how you feel at any given HR will suffice. If it feels easier you are probably more efficient. A 4bpm change in HR is not significant. Don't sweat it.

Dr. Steven F. LeBoeuf


The term "Max Heart Rate" (MHR) is a loaded one. I have always felt that there should be two types of MHR listings -- PMHR (Physiological Maximum Heart Rate) & TMHR (Training Maximum Heart Rate).

PMHR is not significantly affected by training. It is mostly genetic and physiological in nature. There is literally a cap on how fast your heart can ever beat, and there isn't much you can do about it... that's PMHR. In contrast, TMHR is profoundly affected by training, and in fact, a lower TMHR is one of the major fitness benefits of training (for reasons that were eloquently stated earlier by Joe and others on this blog). TMHR does not represent the fastest your heart "can beat" but rather represents the fastest your heart "needs to beat" to reach or maintain an exertion level which is usually at or just beyond your lactic threshold. The higher the PMHR and the lower the TMHR, the healthier and fitness folks tend to be.

Lastly, I'll close by stating that I admire the interest that many have in monitoring their lactic threshold to get their training zones (for a given heart rate). This is definitely a solid way to get HR training zones. That said, fitness training is an amazingly complex thing, and no one metric provides a silver bullet. I think tracking changes in heart rate, breathing rate, lactic threshold, power, and efficiency are all important for personalizing optimal training.

thanks much,

Paul McDonald

Hi Joe this is very interesting as it is exactly what i have experienced over the last 4 years.
I returned to the sport after a long lay off and 4 years ago recorded MHR of 192 on a climb towards the end of a ride.
Each year since then I have got steadily fitter and leaner, to the point where I started competing again last year.
I am currently in the build phase of my training for this season and during some 4min VO2max power efforts on my Wattbike I was only just reaching 170, last year during RAMP TESTS i was reaching 185.
I am well rested at the moment after an adaptation week so dont consider it to be fatigue.
ALSO just like to point out that what you say is pretty much the exact OPPOSITE of what Sally Reed says in her book Heart Zones Training - MHR is static but as you get fitter you can raise your Threshold HR closer to it

Randy Galisky

I am serious recreational rider 3500+ miles a year. Your article describes my personal experience and observations.

1) Can your MHR increase with age, if your fitness improves. Two years ago my MHR was 189 and after a 2 month break in work outs my current MHR is 192? Literature indicates MHR declines with age and should not increase.
2) As I achieve a new lower TMHR during training, should I adjust my MHR setting on my Garmin? My TMHR is about 15 BPM's lower than my MHR

Joe Friel

Randy Galisky--1) Research doesn't report this but I think it's possible if the athlete develops both greater motivation, higher threshold for stress, and more sport-specific muscle mass. 2) TMHR? Are you referring to LTHR? Bottom line, forget your max HR. Of no use. Concentrate on your LTHR for setting zones. Search this blog for details of how to set zones based on LTHR.

Nihal Çelik

I have had an interesting experience today. I am exercising 4-5 days a week, and 2 days of them is running 35 minutes. I add 2 tabata drills (20 sec fast running at max capacity, 10 minutes slow running, total of 8 rounds). My max heart rate for spinning and running is usually 181 or 182. I saw 185 for the first time today while doing the second drill. According to this post, as I get more fit, my xax heart rate should decrease. Is this a bad sign then?

Joe Friel

Nihal Çelik--Really can't say based on 2 data points.

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