VO2 max

NorthCascades

Mine didn't really drop, it's reading lower because the band doesn't fit as well. I just posted that to make you laugh after your experience with wonky numbers. 🙂

ritzvin

dewd2 wrote: »

I only trust the numbers (which were pretty close to my actual value the only time I was tested) when I wear my HRM strap. The HRM on the watch can be way off sometimes. Based on the HR, I once had Strava tell me my effort was less than normal. It was a one mile race (I couldn't go any faster if a bear was chasing me ).

Mine takes a bit of time to rise up during a run... For a really short distance, maybe it was still in the process of shooting up and the average turned out to be lower despite the effort.

sijomial

Been comparing Garmin's VO2 max estimate with Strava's Fitness & Freshness data.....

As they both use HRM and power meter metrics not surprisingly the trends look similar.
Recent uptick in fitness has been driven by higher volume and more hill work.
Not clear to me how the Strava fitness scale from Strava is quantified - score of 74 what?

It's clearly not VO2 max (I wish it was!!!) as Garmin estimates mine at 43 currently.






(Fitness = shaded area, Fatigue = squiggly line.

NorthCascades

@sijomial

Strava's fitness and freshness is their own version of CTL, ATL, and TSB which are proprietary. I don't know what the numbers themselves mean, I suspect they're meant to be understood on a relative not absolute basis. In principal though your fitness is your chronic training load which is the average of your volume over the last 45 or so days. Fatigue is your accute training load, average of your past 7 days or so. Form or training stress balance is the difference between the two; when your fatigue is less than your fitness you're in a good position to go nail some PRs or a race.

Apologies if that was already understood.

sijomial

NorthCascades wrote: »

@sijomial

Strava's fitness and freshness is their own version of CTL, ATL, and TSB which are proprietary. I don't know what the numbers themselves mean, I suspect they're meant to be understood on a relative not absolute basis. In principal though your fitness is your chronic training load which is the average of your volume over the last 45 or so days. Fatigue is your accute training load, average of your past 7 days or so. Form or training stress balance is the difference between the two; when your fatigue is less than your fitness you're in a good position to go nail some PRs or a race.

Apologies if that was already understood.

@NorthCascades

Some already known/guessed but that was very helpful, thank you.

I have a dislike of numbers or scales that aren't properly explained!
74 what? And why a scale of up to 110?

I'll go and calm my chimp with the thought I'm in pretty a good place to start off June's cycling month if I have a relaxed weekend.

Djproulx

sijomial wrote: »

NorthCascades wrote: »

@sijomial

Strava's fitness and freshness is their own version of CTL, ATL, and TSB which are proprietary. I don't know what the numbers themselves mean, I suspect they're meant to be understood on a relative not absolute basis. In principal though your fitness is your chronic training load which is the average of your volume over the last 45 or so days. Fatigue is your accute training load, average of your past 7 days or so. Form or training stress balance is the difference between the two; when your fatigue is less than your fitness you're in a good position to go nail some PRs or a race.

Apologies if that was already understood.

@NorthCascades

Some already known/guessed but that was very helpful, thank you.

I have a dislike of numbers or scales that aren't properly explained!
74 what? And why a scale of up to 110?

I'll go and calm my chimp with the thought I'm in pretty a good place to start off June's cycling month if I have a relaxed weekend.

I'm a bit late to the discussion, but like @NorthCascades, I'm a big fan of the TP software tools. I"m not a Strava guy, so I was unaware that Strava offered a tool that tracks fitness and fatigue over time.

As you've discussed, the TP and Stava tools are measuring "Fitness" (Cumulative Training Load over last 43 days) "Fatigue"(Acute Training Load over the last 7days) and "Freshness" (Training Stress Balance (CTL-ATL=TSB)). TSB is an indicator of "Race Readiness". Many coaches and athletes like to do a periodized build, say 16 weeks, where fitness and fatigue build, with the Fitness value building positive, the Fatigue value building negative, then during a taper, an athlete sheds fatigue much faster than fitness to reach a TSB near Zero on race day, arriving at the starting line "Fit and Fresh".

Regarding the numbers and the relative scale. I don't know all the math and science here, but the cumulative training load is built based on each day's work (over a 43 day rolling period). Each workout is assigned a TSS, or Training Stress Score. I believe the TSS is derived from each session's duration and intensity. (a one hour run gets a lower TSS than a combined 3hour bike/45min run workout) This is all nicely displayed on the graphing tool that allows a look back and forward up to 730 days. The tool can show swim, bike, run fitness individually, or in the case below, the combined fitness:




Finally, when talking about endurance sports, I think of the CTL score as a measure of where I am in fitness against where I need to be on race day to finish a race strong. The chart attached shows triathletes training for various distance races the expected hours/week, TSS/week and overall CTL (fitness) levels needed to complete the events.

NorthCascades

I think this is already clear but just in case.

TSS = training stress score. An hour at FTP gets you 100, 2 hours at half your FTP also gets you 100. FTP being as hard as you're capable of for an hour.

TSS = 100 * (seconds * (avg power / FTP) / 3600)

Actually I just looked it up and either I remember wrong or this is needlessly complicated.

TSS = (sec x NP x IF)/(FTP x 3600) x 100

Now I'm confused.

Djproulx

NorthCascades wrote: »

I think this is already clear but just in case.

TSS = training stress score. An hour at FTP gets you 100, 2 hours at half your FTP also gets you 100. FTP being as hard as you're capable of for an hour.

TSS = 100 * (seconds * (avg power / FTP) / 3600)

Actually I just looked it up and either I remember wrong or this is needlessly complicated.

TSS = (sec x NP x IF)/(FTP x 3600) x 100

Now I'm confused.

I'm too lazy to do the calculation on one of my workouts to see how the equation proves out, but the other variables are Normalized Power (an algorithmic estimate of the physiological cost of a workout) and Intensity Factor (the relative intensity of a given workout without regard for duration).

These two metric values are still taped to my bike. For the Ironman bike split, the only metrics I watched during the 6& hour ride were maintaining Power at 155-160 and keeping the IF at .72 over a hilly course. The purpose and value of riding to these outputs was to conserve as much energy as possible for the marathon to follow.

dewd2

During my morning run yesterday the topic of VO2max came up. The guy I was running with commented that Garmin gave him a number in the 40's. Garmin gives me numbers generally in the mid 50's. Knowing that my friend I was running with could kick my *kitten* any time he wanted made me think.... He has been running trails with ungodly amounts of vertical gain for the past 8 weeks and I have started to add speed work back into my routine. I would bet the different approaches we are using to training is the reason because the numbers make no sense any other way...

ETA - To me this makes the measurement only useful if you are doing the type of training that allows it to be measured more accurately. Slow trail miles (even extremely challenging ones) will not produce an accurate result. YMMV.

sijomial

dewd2 wrote: »

During my morning run yesterday the topic of VO2max came up. The guy I was running with commented that Garmin gave him a number in the 40's. Garmin gives me numbers generally in the mid 50's. Knowing that my friend I was running with could kick my *kitten* any time he wanted made me think.... He has been running trails with ungodly amounts of vertical gain for the past 8 weeks and I have started to add speed work back into my routine. I would bet the different approaches we are using to training is the reason because the numbers make no sense any other way...

ETA - To me this makes the measurement only useful if you are doing the type of training that allows it to be measured more accurately. Slow trail miles (even extremely challenging ones) will not produce an accurate result. YMMV.

@dewd2

Joe Friel touches on an interesting subject in book I read earlier this year (Fast After 50)....

VO2 max is only a measure (or estimate in Garmin's case) of oxygen uptake and not directly a performance metric.
Apparantly Olympic marathon winner Frank Shorter had a really ordinary VO2 max (in comparison to other elite runners) but appeared to use that oxygen far more efficiently than other runners judging by his speed and results.

Would be a fascinating comparison if you and your friend were following the same programme and at same point in the same program.

In Garmin's case I see the same thing as you in that long slow rides skew the VO2 estimate downwards and short intense rides skew it upwards. My score can zigzag quite nicely especially indoor training with less variables when clearly my actual oxygen uptake ability isn't changing day by day. The extended trend seems reasonable/believable for me though.

NorthCascades

Riding as fast and hard as I can sometimes takes my Garmin estimate of VO2 down a notch, then it comes back up after the next ride if it's a little bit more mellow. I've been doing mostly threshold lately, yesterday I went out and tooled around in Z2 for an hour and came home to a point higher value. I know it's a version of PWR:HR, and the hard rides mean a high HR, I've always assumed that's why I see this.

For running they use pace in place of power, and the white paper says they do a lot of filtering of the data to only look at the points they consider most reliable. I don't know what they're doing on the bike but it's probably also not something you'd do on the back of a napkin.

BrianSharpe

dewd2 wrote: »

During my morning run yesterday the topic of VO2max came up. The guy I was running with commented that Garmin gave him a number in the 40's. Garmin gives me numbers generally in the mid 50's. Knowing that my friend I was running with could kick my *kitten* any time he wanted made me think.... He has been running trails with ungodly amounts of vertical gain for the past 8 weeks and I have started to add speed work back into my routine. I would bet the different approaches we are using to training is the reason because the numbers make no sense any other way...

ETA - To me this makes the measurement only useful if you are doing the type of training that allows it to be measured more accurately. Slow trail miles (even extremely challenging ones) will not produce an accurate result. YMMV.

There could be other factors at play too. Is there a significant age difference? A VO2 max in the 40s is good for an old phart like me but not for someone much younger.

Has he upgraded his watch recently? When I switched over to my Fenix 5 my numbers were all wrong (V02max was insanely low and Garmin Connect gave me a fitness age of 75 until it "learned" me again)

heybales

I had some research notes from the past, don't know if in current FirstBeat whitepaper, that shared they took the basic research in this study and tweaked it.

www.ncbi.nlm.nih.gov/pubmed/2287267

The PAR table of frequency and time of workouts came from that, with additional levels they added.
Of course you can pick your level in GC settings - but pretty sure current devices are just doing a rolling avg of the workouts it knows about.
And instead of specific level numbers, probably a continuous range.

So to me a current short workout being examined for time only, replacing a past one that may have been longer - makes sense to drop the VO2.
Age does make a difference, again could do whole number age or continuous range.

Here's the formula as it used to be. And when Garmin first would show it's estimated VO2max, it matched using the figures I thought they were probably using. Haven't compared or done the math in ages though.

=Gender M=1, F=0 * 10.987 + 56.363 + 1.921 * PAR value from 10 level table - 0.381 * Age - 0.754 * BMI

I guess the kicker is how far back into workouts are they going to establish those PAR table levels.
And of course other tweaks since way back involving watts or pace.

See if this table shows up correctly.

dewd2

BrianSharpe wrote: »

dewd2 wrote: »

During my morning run yesterday the topic of VO2max came up. The guy I was running with commented that Garmin gave him a number in the 40's. Garmin gives me numbers generally in the mid 50's. Knowing that my friend I was running with could kick my *kitten* any time he wanted made me think.... He has been running trails with ungodly amounts of vertical gain for the past 8 weeks and I have started to add speed work back into my routine. I would bet the different approaches we are using to training is the reason because the numbers make no sense any other way...

ETA - To me this makes the measurement only useful if you are doing the type of training that allows it to be measured more accurately. Slow trail miles (even extremely challenging ones) will not produce an accurate result. YMMV.

There could be other factors at play too. Is there a significant age difference? A VO2 max in the 40s is good for an old phart like me but not for someone much younger.

Has he upgraded his watch recently? When I switched over to my Fenix 5 my numbers were all wrong (V02max was insanely low and Garmin Connect gave me a fitness age of 75 until it "learned" me again)

He's actually younger by a few years (I'm 51 - he's 40something). He's had the same watch for at least a year.

Garmin says I'm a very fit 20 year old. Garmin obviously hasn't seen me trying to walk first thing in the morning.

dewd2

sijomial wrote: »

dewd2 wrote: »

During my morning run yesterday the topic of VO2max came up. The guy I was running with commented that Garmin gave him a number in the 40's. Garmin gives me numbers generally in the mid 50's. Knowing that my friend I was running with could kick my *kitten* any time he wanted made me think.... He has been running trails with ungodly amounts of vertical gain for the past 8 weeks and I have started to add speed work back into my routine. I would bet the different approaches we are using to training is the reason because the numbers make no sense any other way...

ETA - To me this makes the measurement only useful if you are doing the type of training that allows it to be measured more accurately. Slow trail miles (even extremely challenging ones) will not produce an accurate result. YMMV.

@dewd2

Joe Friel touches on an interesting subject in book I read earlier this year (Fast After 50)....

VO2 max is only a measure (or estimate in Garmin's case) of oxygen uptake and not directly a performance metric.
Apparantly Olympic marathon winner Frank Shorter had a really ordinary VO2 max (in comparison to other elite runners) but appeared to use that oxygen far more efficiently than other runners judging by his speed and results.

Would be a fascinating comparison if you and your friend were following the same programme and at same point in the same program.

In Garmin's case I see the same thing as you in that long slow rides skew the VO2 estimate downwards and short intense rides skew it upwards. My score can zigzag quite nicely especially indoor training with less variables when clearly my actual oxygen uptake ability isn't changing day by day. The extended trend seems reasonable/believable for me though.

Yes, the whole running economy thing. I'm not sure we'd ever follow the same program since he is primarily a trail runner and I tend to run road races more.

I really should get that book but I'm not sure I want to admit I'm over 50 yet.