Can you only measure your HRmax correctly when you're unfit..?
neeb
Posts: 4,467
So I took 8 days off the bike completely and then did a fairly intense indoor session today. HRmax about 5-10 bpm higher than it's been for months, but I know that after 2 or 3 more regular sessions it'll be back down to it's usual level again.
It seems weird that your heart is only capable of reaching its maximum rate when you are temporarily slightly out of condition. Especially when that faster rate doesn't actually correspond to more power.
Should you regard your HRmax as the level it normally is when you are training regularly, or the level it's capable of reaching if you take a week or two off and then really push it?
Is doing the latter good or bad for you? ;-)
It seems weird that your heart is only capable of reaching its maximum rate when you are temporarily slightly out of condition. Especially when that faster rate doesn't actually correspond to more power.
Should you regard your HRmax as the level it normally is when you are training regularly, or the level it's capable of reaching if you take a week or two off and then really push it?
Is doing the latter good or bad for you? ;-)
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More likely is that your usually tired so you're not as fresh to push hard enough to hit your max.
<edit - what I mean is that I can push the same power when I'm "tired" - just at a lower HR.
I'm also just interested in what is happening in the cardiovascular system to explain the inconsistent relationship between power and HR. For me at least, this inconsistency seems to relate to training load, in fact it's the most obvious thing I notice that varies with the amount of training I'm doing on a day to day or week to week timescale. HRmax is just one aspect of that, but as it does represent the maximum rate at which the heart can work, it's quite an interesting figure.
MHR decreases 1-2bpm per year as part of the body's natural ageing process, so good luck with that. Decreased MHR does not necessarily equal decreased performance though - it's not a linear equation. Plenty of science to back that up and plenty of 50+ riders still riding at E/1/2 level to provide the anecdotal support of that.
Your inability to hit MHR on some days and not others is not an indication that your MHR varies day-to-day. It is simply an indication that you can hit it on some days and not others.
It's simpler just to stick with the established definitions, surely - rather than trying to redefine something in order to fit with your individual scenario.
Other than being useful for setting training zones (which can also be set using different measures, like LTHR), then MHR is not a particularly relevant training metric for daily use. As I said before - it is not an indicator of potential or performance, especially given that 99% of performance training will be done at levels significantly below MHR anyway..
Mine seems to have declined by about 7bpm in the last 10 years. Clearly it's related to aging, so you could hypothesise that a training regime that minimises decline over years might also be good for general maintenance of cardiovascular condition against age related degeneration. It could relate to questions such as whether short intense sessions or long endurance miles were better for minimising aging of the cardiovascular system.
Would certainly be useful if the principal objective of your training was to minimise CV ageing - but I suspect it probably isn't.
On the contrary, I suspect it's been studied at great length.
That would be relevant if MHR was an indicator of performance - but it isn't.
It's possible I suppose that as you get older, your heart beats slower but also gets larger to compensate, especially if you are trying to subject it to the same load. But if so my guess is that it would be due to the tissue becoming more sclerotic / less flexible. So I'd probably want to stick with small and fast if I had the choice..
But as far as I know the trend for MHR to decrease with age is more marked in unfit people than in fit people. Also, as rather few things that are associated with aging are good for you, I think it's not unreasonable to assume that if your MHR decreases less over the years that's considerably more likely to be good than bad.
Although it's possible I suppose that the reason MHR decreases with age is to protect the heart from damage as it gets more sclerotic, and that it could be dangerous to override that (assuming it was possible to do so).
Training level and fatigue are but two of dozens of factors that will influence HR response. Somewhat confusingly, fatigue can result in both an elevated and a suppressed HR response. And of course stroke volume and blood plasma volume are also affected by training (and de-training).
Not quite, it represents the maximal rate the heart might beat but that does not imply it is performing work at a maximal rate, and by that I mean cardiac output (amount of blood being moved per unit time).
CO is a function of various things and not all of them relate to the heart alone, there are extra-cardiac factors as well. While an increase in HR generally means an increase in CO, too high a HR can also impair CO.
I think I've noticed a similar thing on a much shorter timescale when I do something like run up four flights of stairs from a relaxed, un-warmed-up standing start. When I get to the top my HR will be really rapid, but if I keep monitoring it for a minute or so it usually gradually transitions to a really quite slow rate, actually slower than it was before I ran up the stairs. I think what's happening is that the sudden burst of activity takes the heart by surprise (hence the initially rapid rate), but that there is a more delayed response in the form of an increase in stroke volume. It's as if the heart is "ticking over" at a low stroke volume until exercise stretches it a bit and allows it to pump at a greater volume. But the initial sudden response is a an increase in HR, because that seems to be able to happen more quickly.
Hope that makes sense - a large element of subjectivity involved obviously..
Measure after your activity.
Is there a difference ?