Cardio fitness

Hodders

Hodders

Hodders

Soldato
Joined
18 Oct 2002
Posts
5,243
Location
Riding my bike
I'm trying to learn more about cardio fitness.

Everything on the web seems simplified down to - 220 minus your age = max HR. Then work out zones from there.

What I'm trying to understand is how to effectively measure change in cardio fitness as a result of excersise and training.

For example - case study:

A 54 year old bloke, healthy but carrying a bit of extra weight. Resting HR of about 70.

At the beginning of an exercise program finds that:

Sustained HR of 155 is the threshold at which he can have a conversation. 3, 4 word sentences are OK, breathing heavily. I'm assuming this is the anaerobic threshold?

What changes to these figures would you expect to see as his fitness increases - up down constant?

My understanding is - heart gets fitter, beats more efficiently, pumps larger volumes of blood each beat, muscles use energy more efficiently. Should translate into:

*) Resting HR drops
*) FTP goes up - enabled by heart beating faster at same perceived effort level, more blood flowing, muscles getting more efficient.

It's a really interesting area!
 
I think the (220 - age) thing is an average for a population and won't be accurate for an individual. Mine tops out around 180, but that equation would give 164.

Otherwise I believe you're right with what you expect - as you get fitter your heart can pump more blood per beat, meaning it doesn't need to beat as fast while resting and able to push more blood around when needed. Other physiological changes mean your lungs and muscles work more effectively. Although FTP is used in cycling, VO2max seems to be used more widely as the main measure of cardio 'fitness'. My Garmin fenix provides an estimate - the absolute number might not be very accurate but the increases and decreases seem to correlate with training effort.

I suspect that everyone responds differently to exercise, e.g. genetics and your fitness starting point, and the only way to find out what will happen to your resting HR and FTP etc. is to try it.

It is an interesting topic - I did a fair bit of reading on it, partly prompted by trying to understand if my lowering resting heart rate might be a concern (apparently not). That was a while ago though, meaning I've forgotton most of it!
 
https://crickles.casa/ is mainly about heart data.

https://intervals.icu/ looks at your power and heart data.

Both donateware and give you heart rate zones based on your estimated Lactate Threshold Heart Rate, these days I'm more inclined top believe the Intervals value, as Crickles fluctuates wildly as if it presumes every ride it processes is a threshold+ workout... Which is highly unlikely to be the case.
 
I'm 50 years old, have a resting HR of around 54/55 and on a full bore sprint I can see 190bpm. In a 1 hour race scenario I'll see 170bpm average.

These guides really do need to be taken with a pinch of salt.
 
All good stuff. Thanks.

I'm more interested in what trends to expect.

2 years ago as my HR approached 160 I would have started to feel super out of breath. Now after regular exercise that figure is up nearer 175. 155 feels really comfortable with conversation easy. Not much change in resting HR. But it has gone down a bit to about 63.

I really am a data nerd so looking at a totally unnecessary power meter for my bike now...
 
Hodders said:
All good stuff. Thanks.

I'm more interested in what trends to expect.

2 years ago as my HR approached 160 I would have started to feel super out of breath. Now after regular exercise that figure is up nearer 175. 155 feels really comfortable with conversation easy. Not much change in resting HR. But it has gone down a bit to about 63.

I really am a data nerd so looking at a totally unnecessary power meter for my bike now...
Click to expand...

In that case, you might want the 4iiii bargain that was advertised on hotukdeals earlier if it fits your crankset, £185 (but if you have loyalty points you could knock another £10 off that) https://www.hotukdeals.com/deals/4iiii-precision-r7000-105-powermeter-3932811 (I have one, paid almost double this 4 years ago, usually use it on turbo these days instead of Direto power source)

Just like power performance, your heart rate performance is dynamic, especially once you start "training." Since '17 (I had just turned 43) when I started cycling for fitness, my LTHR (very crudely what heart rate I can maintain for ~20mins, z4) has been as high as ~175 and as low as ~150 just after respiratory infections. Currently Intervals.icu reckons its ~170, but for me it's usually my legs screaming than concern for my heart rate being 170-185ish, just like yesterday's lunchtime sprint race https://www.strava.com/activities/7118250741/analysis . I drink an awful lot of caffeine when at home, one of many things that can affect heart rate data, but the other day I was shocked to see 38bpm while at my pc desk havig drank a typical amount of daily caffeine when the lowest I've seen before is ~45, in 2016 when very overweight I could be resting at 70-80bpm.
 
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A bit of a data nerd here too, and the combination of power meters on the smart bike plus the fenix and Strava gives lots to look at. I find it helps keeps me motivated, and there's a stupid sense of achievement in beating previous Zwift KOMs/routes times and nudging the power curve upwards.

I've no idea if these sorts of changes are typical, but FWIW going back a couple of years I was reasonably fit from swimming and had a RHR of about 50 and VO2max about 45. Since getting 'into' the cycling, Garmin tells me that my RHR has dropped to about 40 and VO2max is high 60s (admittedly helped by losing some weight). That was before I got covid last month - sadly I'm still trying to get back to where I was.
 
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