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I've been using a fairly basic Garmin device for the last year - it's a Vivoactive 3.
During that time, my calculated vo2 max dropped steadily over the winter from 53 to initially around 47, then in the last month or so down to 44.
By way of background, I'm 39 and weigh 72kg, resting heart rate of 44ish. These things are constant over the last year. I don't do any other sports than cycling.
Compared to other people on Strava, I tend to have a much lower heart rate during even hard-feeling efforts - often as much as 50-60bpm lower for a given segment! I don't often go beyond heart rate zone 3 on a ride, no matter how hard I try.
On reflection, I probably trained quite hard without realising it in 2018 (started using Strava after many years of resisting it!), but not so much in 2019... although I am similar in times. I cycle about 6,000km a year, every year.
Anyone care to offer any suggestions on what's going on with the vo2 max calculation? I feel like it's telling me that I'm turning into an old giffer!
It's not measuring VO2 max. It's probably measuring Heart Rate Variation and using that as a proxy for VO2 max, but as HRV varies a lot by individual and by how tired / stressed you are, it's probably no more accurate than rolling a dice.
If you really want to know your VO2 max you need to get it measured properly eg on a turbo with your expired breath being analysed etc. Contact your local Uni, the Sport Science Department will often be able to test you for a nominal fee.
As for your HR, it sounds like you just have a large heart which beats more slowly (as it has a higher stroke volume). So I guess all your HR zones are completely out if you've based it on the 220-age rule (which is also like rolling a dice). It over predicts max HR for 50% of people and under predicts for the other 50%; it's just a crude average and the Standard Deviation is about 20 bpm.
Your heart rate monitor might not be rieading right. Try taking your pulse at rest and walking briskly just with the old finger on the pulse and a watch method, and compare.
Interesting - thanks.
I suppose all I'm really interested in is why one estimated measure (vo2 max) would decline so clearly over the year, when all other things appear equal.
The Garmin algorithm compares your pace during an activity and your heart rate at the same time. Ie if you can go fast with a slowish heart rate, your reserve is greater than someone whose heart beats more for a given pace.
This will all be based on assumptions around your height / weight / body surface area / Max HR and is just an estimate. Having said that, it looks as though it’s fairly accurate according to reports (+/- 3-4ml/kg/min).
In your case, it looks like (for whatever reason), your HR is trending higher for a given activity. This may be due to a degree of deconditioning? Either way, with the above assumptions in mind, I don’t think there’s is too much to worry about.
If you are using the Garmin wrist based measurement for HR - I find that reads a lot lower than reality when on the bike
Vivoactive 3 hr is bollocks, get a chest strap.
My vo2 max has dropped off from 53 to 50, and I'm fitter than I was when it read 53.
I don't have much faith in the vo2 algorithm.
Having said that, it looks as though it’s fairly accurate according to reports (+/- 3-4ml/kg/min).
I'd be interested to see the sample size and demographics. I bet it's a small homogeneous group filtered so the results look good ie anyone too far off was dropped.
Olympic athletes go from 40s to 90s, make of that what you will.
I agree with footflaps. I've been reading up on HRV as a basis for VO2max and it sounds, well, approximate at best. Also if you can't get out of Zone 3 you probably have your zones wrong. How did you set them - Threshold test?
Zone 4 should go up to your Lactate Threshold Heart Rate, roughly the highest you can maintain for 20mins. For me, that is 155-165bpm, according to my https://cricklesorg.wordpress.com/ account.
By default, Strava simply creates five zones according to the max heart rate you tell it.
I still can't explain why my LTHR has dropped from ~175 to 165 over the last ~14 months. I'm nearly 46, hit 189bpm on a short sprint last week, did hit 194bpm last year. Gone from 73Kg to 81Kg over the last 26 months, most of the gain over winter 2017 and then stayed 78+ since. I've done a lot less 3+ hour outdoor rides this year, which in the past often involved VO2 max power intervals up the cat4 hills, I suspect that I've not been making my easy rides on the turbo easy enough until recently, to go alongside relatively tough sessions... Perhaps overtraining.
You need to differentiate between poor performance in the recovery period following an intense session or competition, and overtraining. I doubt many people on here have enough free time to properly overtrain. The objective is to have a rising saw tooth pattern of increasing fitness. Effort followed by enough recovery (which can be active recovery) to be stronger than before the effort. It's only when after even an extended recovery period after the effort that you're weaker rather than stronger that you can talk about over training. And the answer then is more recovery and less active recovery.
Did you check your heart rate monitor against a stop watch and finger on the pulse at a brisk walk, Ben?
during even hard-feeling efforts – often as much as 50-60bpm lower for a given segment! I don’t often go beyond heart rate zone 3 on a ride, no matter how hard I try.
That's because optical heart rate measurement is horse shit during hard efforts.
Zone 4 should go up to your Lactate Threshold Heart Rate, roughly the highest you can maintain for 20mins. For me, that is 155-165bpm, according to my https://cricklesorg.wordpress.com/ account.
The best way to find your zones is to do a lactate test, you sit on a king cycle running a ramp test and they take blood from your earlobe every minute or so and measure the lactate.
You can move your zones around by 10bpm or more in a few months training eg
[url= https://live.staticflickr.com/65535/48389153712_1d2c712f1d_z.jp g" target="_blank">https://live.staticflickr.com/65535/48389153712_1d2c712f1d_z.jp g"/> [/img][/url][url= https://flic.kr/p/2gHZ4xE ]Lactate test results[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
I think the main thing a results sheet like that says is that you're so far off the pace that you aren't going to win anything significant and you may as well forget all this training rubbish and just get on with enjoying your sport with nothing on the handle bars apart from brake and gear levers and nothing on your wrist. 😉 I made that decision a few years back. 🙁
If you read the paper it's based on the VO2 max calculation for running seems fairly accurate. After a very significant block running training my VO2 max steadily rose and that coincided with the increase in my running performance.
I have no idea how it can do it for cycling there just seems far to many variables. Mine has just plummeted as the last two rides I'd did was with a fully laden bikepacking bike pulling an extrawheel loaded with camping gear.
I was struggling to maintain 12mph on the high peak trail my heart was similar to when I'm riding 20mph on the flat on my road bike.
I also have to agree the wrist based HRM is bobbins or my wrist just doesn't work with them. Get a strap if you want an accurate HR reading.
That’s because optical heart rate measurement is horse shit during hard efforts.
Why is that?
Consumer grade units are Inaccurate at hard effort.
Case in point Ben doing hard efforts at 50-60 BPM less than others.
I can do a hiit session on the track and bury my self .....using optical I won't even break 120....
It's pretty well documented to be fair BMC reckon that they are within 10bpm 90% of the time across a broad range of activities(ranging from sedentary to the gym). With them diverging when your exercise gets intense tending to less accuracy at the intense end.
Because it's using an indirect measure rather than the electrical signal from the heart.
Are you referring to wrist watch type HRMs or all opticals? A far as I know the Polar OH1 measures pretty accurately against chest HRMs.
Oh1 along with the Apple watch are the most accurate but still lag a chest strap and throw out many more anomalies than a chest strap.
Check DC rainmakers overlay graphs of him wearing 3/4 device at once to record an activity for comparison
Do you want an amusing gadget or something relaibale enough to make use of the investment you've made in tests like footflaps has posted and hours of effort in training, an appropriate diet... .
There's not much point in knowing that the lab tests say beyond 170bpm you're in the red on a three-hour effort if your HRM is accurate +/- even 5%. Use an ECG based monitor if you want numbers you can believe. And even knowing you're in the red at 170bpm isn't much use IME. Well trained, well rested and highly motivated by a competition I found that I could go harder for longer than the lab tests said was possible.
Check DC rainmakers overlay graphs...
Yes I've seen that. Mrs SOM and I both use OH1s and (as far as we can ascertain) they work well. Mind you we are not training for the TdF.
Thanks for all the info chaps.
The hear rate reading seems accurate within a few bpm based on my own quick measures, although I completely see the limitations of it as a very basic tool and the associated calculations / estimates it makes.
I take it that the vo2 estimate is approximate at best and, if anything, is just telling me that I'm pushing myself less hard over this year.
To add a little to my anecdote about heart rate during efforts... My neighbour cycles a similar commute to me. He's a good 10-15kg heavier than me and, although close to some of my times, he's often in the range of 170-180bpm whereas I'm 120-130 on flat segments.
Obviously huge caveats apply in making comparisons (if my watch even works!), but it's worth noting that he's a recent cyclist (me, lifelong) and that I have a very low cadence compared to most people. Maybe I'm just a skinny diesel, whereas he and some others are more substantial spinners!
The hear rate reading seems accurate within a few bpm based on my own quick measures, although I completely see the limitations of it as a very basic tool and the associated calculations / estimates it makes.
Are you measuring that when you're at the end of an interval and about to throw up, or just walking around? It's fine for the latter case, not so good for the former. If you're serious about using HR you really ought to invest in a chest strap, they're not that expensive.
(Should say optical HR is fine for day-to-day health monitoring, just not so good for the intense stuff).
My vo2max has tracked pretty much as expected over the year, went up to 65 in April training for a race and doing a fair amount of HIIT and a high percentage of runs at threshold. Slacked off doing long slow mountain runs over the summer and injury interruptions fell back to 60. Now creeping back up as I've recovered from injury, and the colder evenings encouraging me to bang out faster runs again. Can't say I've had much issue with my 735xt regarding heart rate, sometimes I use a chest strap, sometimes I don't, and from what I see they're generally in line with expectations