basilic wrote: ↑
Thu May 23, 2019 9:08 am
this is not quite right.
The various formulas based on age are meant to predict the average
maxHR for a given age group, not
individual values. There is always variance between individuals of any age. Eg the link below examines measured maxHR of marathon runners, and reports a standard deviation of 10.2 mmHg (table 1) for maxHR, and 8.5 mmHg for the difference between measured maxHR and the value predicted by the Fox formula (220-age) (I am using this paper because participants are all trained athletes, the variance is even greater in the general population). So if the distribution was normal (or close enough), 95% of athletes would be within +-17 mmHg of the predicted value. Eg, if you are 40, predicted maxHR is 220-40=180 bpm, and most athletes aged 40 have measured maxHR between 163 and 197 bpm. Even if you were outside this range you should not be necessarily alarmed or suspect error, since 5% of people will be outside by definition.
https://www.ncbi.nlm.nih.gov/pmc/articl ... -00226.pdf
So if you are going to train based on HR zones, you better get the maxHR right. This means no formulas, do a maximal stepped stress test until your eye sockets bleed or you spill your guts, whichever comes first.
PS: in a post on previous page a iheartbianchi cites a paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4919019/
that concludes thus:
However, Bland-Altman revealed high limits of agreement (upper 25.31 and lower −24.67)
So this is even greater variability, the hypothetical 40 year olds would range from 155 to 205 bpm. The population is not limited to athletes.
I thought we were all in agreement that formulas are off and should only be used as a very rough guide.
If the point is that there are significant differences in average maximum HR by age, we have to be very careful to really think about what this means in real life. If we look solely at the absolute range of maximum heart rates, yes you can come up with some wild gaps (you cited one example of 50...huge). But if you are presented with a 40 year old athlete who says their maximum heart rate is 155bpm, I surely hope your immediate response is not, "oh that's perfectly within the range and so you're fine," even though of course you would be right in saying though. What I hope you would say is, "that's nothing to be concerned about, but it's actually pretty far below the mean line, so let's do another test just to make sure." "Also let me know if you feel unwell or there's something else bothering you." This is I think the prudent and thorough thing to do. Because let's be intellectually honest here - it is much more likely that a 40 year old will have a Max HR of 185bpm as opposed to 155bpm. If you do another test, hopefully supervised this time, and you eliminate all other possible factors, and you still get 155bpm, well that's just where you are and that's that.
It's a similar analysis when medical professionals see a patient presenting with a somehwat elevated heart rate of maybe 75bpm while sitting. This is within the "normal" range, but it would behoove the doctor to suspect an infection or depending on any other symtpoms, some other underlying cause.
As mentioned earlier, Figure 1 in the study I cited shows a very dense number of results close to the mean line, hence the survey results indicate an average deviation from the mean line of 15bpm. This is about what I would normally expect, and anyone who is too far above, or too far below, I would be immediately suspicious. I met a 50year old recreational cyclist who told me his max HR was 210. He showed me his Strava to prove it. I had him change the battery on his HR sensor, checked his meter positioning, had him turn off his phone/bluetooth, other bike sensors etc. to make sure there was no signal interference, made sure he worked up a good sweat to ensure good contact and then had him do the test again. He couldn't get his HR over 175. Yeah, he was bummed out, but at least he no longer was training at HR zones that were wholly inappropriate for him.
Also, as stated in that study, "Leg fatigue was the primary test termination criteria in 82% of the exercise tests" so if you are doing a cycling test, make sure leg fatigue is not coming too early.