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Quantifying the "degree of difficulty" of a given erg session

Posted: October 17th, 2024, 1:20 am
by Ombrax
Has anyone out there (say, an exercise physiologist) ever developed a somewhat scientific way of defining how difficult a given workout was, preferably tailored to a specific person (so it would be based on your individual capability instead of an arbitrary scale).

I suppose you could try something based on time spent in various HR zones, where you get more credit (using non-linear factors?) for work in UT1 compared to UT2.

Or, if you knew you erg pace corresponding to VO2 max and FTP, you could use watts or pace and time in condition, without messing with HR.

I was just wondering, but it certainly could have practical applications as you develop an individual workout plan and look for ways to push yourself and improve your performance based on how your body is responding over time.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 17th, 2024, 1:47 am
by JaapvanE
RPE is a pretty decent scale, and quite personal. I admit RowsAndAll has a different scale than Garmin, but I use both. Sometimes after a tough day on the office sessions just feel awful. HR Zones are usefull, but also limited as they don't account for stress factors and muscle issues. And often I aim for a specific zone, so HR is capped, pace often quite similar but it is how much I had to struggle to stay in my intended zone.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 17th, 2024, 3:40 am
by iain
JaapvanE wrote:
October 17th, 2024, 1:47 am
RPE is a pretty decent scale, and quite personal. I admit RowsAndAll has a different scale than Garmin, but I use both. Sometimes after a tough day on the office sessions just feel awful. HR Zones are usefull, but also limited as they don't account for stress factors and muscle issues. And often I aim for a specific zone, so HR is capped, pace often quite similar but it is how much I had to struggle to stay in my intended zone.
Personally I feel HR is a better measure than RPE as a "moderate" session when we are all out can take more toll than a harder session when we are fresh. That said, HR is less good at the top end as achievable HRmax does decline when we are tired so sometimes I need to consider 95% of normal HRmax is my effective maximum that day and calibrate accordingly. ALso, we need to be aware of our personal HR bands as these vary both through time as well as between people and prescriptions of 90% HRmax or 85% HRR will be working at different intensities for different people or on different days. That said, personally endorphins insulate me from what I am putting my body through. In the extreme, I have never felt significant pain during races even when my muscles have gone to jelly and I am unable to manage more than 1/4 slide! Similarly I usually feel worse during the opening 15 min than later on SS rows even if I speed up at the end and push into AT territory rather than UT2, so RPE is definitely not that useful a guide for me to the physical demands.

There was an article by Eddie Fletcher about the relative impact of duration against intensity. He concluded that a tough 30R20 required a full day's rest to recover from while an FM took 7 days.

It seems to have gone out of vogue recently, but there used to be the concept that Over-reach was a good way to force adaption (assuming appropriate recovery program afterwards), so I have always considered that pushing when tired was fine so long as it wasn't for several days in a row and that I accept that my pace will be affected.

Also there are different elements of a session. We need to consider CV load (ie Eddie's focus), but also muscular tiredness and the psychological toll the session makes. The latter is the most influenced by the rest of our lives, but I know that some sessions require a mental drive that sometimes I just don't have when work & life have drained my mental resilience. Many programs (and Eddie's writing) seem to be based on an assumption that tiring muscles is fine and that to avoid over training we just need to ensure that CV load is managed, but I have never seen any research that investigates this. I understand why programs don't account for the mental demands as these are often outside the training regime and particular to the individual and time of each session (although being cumulative). So while avoiding falling into a CBA mindset, we do need to calibrate training to what we are up to on the day.

Finally (and apologies for such a long response) there is the old adage that there are no "easier" sessions, just faster ones. Obviously this doesn't apply to sessions where we deliberately cap efforts below what is achievable. Also a session needs to be evaluated in the context of what that person is used to. a 5k for one person will be a challenge to complete while a short hard effort for another.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 17th, 2024, 10:23 am
by Dangerscouse
Ombrax wrote:
October 17th, 2024, 1:20 am
I was just wondering, but it certainly could have practical applications as you develop an individual workout plan and look for ways to push yourself and improve your performance based on how your body is responding over time.
For me personally, I find that my range of capability is too varied on any given day. Some days I'll HD at circa 90% HR, maybe closer to 88%, and I've had others that have felt manageable but were circa 95% HR.

I wish I knew the differences between when it was 'on' or not, but despite trying to find correlations, I've always struggled.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 17th, 2024, 12:08 pm
by Sakly
Dangerscouse wrote:
October 17th, 2024, 10:23 am
Ombrax wrote:
October 17th, 2024, 1:20 am
I was just wondering, but it certainly could have practical applications as you develop an individual workout plan and look for ways to push yourself and improve your performance based on how your body is responding over time.
For me personally, I find that my range of capability is too varied on any given day. Some days I'll HD at circa 90% HR, maybe closer to 88%, and I've had others that have felt manageable but were circa 95% HR.

I wish I knew the differences between when it was 'on' or not, but despite trying to find correlations, I've always struggled.
Me too. There were too many variables, and some of them are mentally, so even harder to "measure".

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 17th, 2024, 12:58 pm
by jamesg
how difficult a given workout was
"Difficulty" can refer to a percentage of 2k test Watts; or some other benchmark you may like better.

Of a 2k test Watts, 60-80% will be distance work, 95% and up is race tapering. Threshold 80 to 85%.

For Was, using your benchmark you can see where each past piece stands.

See: http://3.8.144.21/training/interactive

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 17th, 2024, 6:56 pm
by putridp
Intervals.icu and Strava's fitness scores are flawed but nonetheless seems to have some value in measuring a workout's difficulty and following contribution to fitness and fatigue. I'm not particularly the familiar with each one's algorithm. I think intervals.icu uses HR and duration to create a load score for each workout, then uses a weighted moving average over 7 weeks to create a fitness score, and a 7 day moving average to create a fatigue score.

They seem to be ultimately flawed, especially if you mix different types of activities, but I find it motivating to have some sort of objective metric.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 18th, 2024, 2:45 am
by JaapvanE
AFAIK, intervals.icu and RowsAndAll use EPOC, as does Garmin (see https://www.firstbeatanalytics.com/en/f ... ning-load/). Might indeed what is looked for.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 18th, 2024, 8:42 pm
by Ombrax
JaapvanE wrote:
October 18th, 2024, 2:45 am
AFAIK, intervals.icu and RowsAndAll use EPOC, as does Garmin (see https://www.firstbeatanalytics.com/en/f ... ning-load/). Might indeed what is looked for.
Interesting - thanks for posting, that useful information. I Googled EPOC which leads to a lot of info directly related to my question.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 19th, 2024, 6:50 pm
by Dave Neve
"Has anyone out there (say, an exercise physiologist) ever developed a somewhat scientific way of defining how difficult a given workout was, preferably tailored to a specific person (so it would be based on your individual capability instead of an arbitrary scale)."

I just look at the amount of sweat I leave around the RowErg :D

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 20th, 2024, 4:07 am
by Dangerscouse
JaapvanE wrote:
October 18th, 2024, 2:45 am
AFAIK, intervals.icu and RowsAndAll use EPOC, as does Garmin (see https://www.firstbeatanalytics.com/en/f ... ning-load/). Might indeed what is looked for.
This does look good on face value, but my personal experience of HRV is very patchy.

I'd feel great and it would give me a terrible score and vice versa. Admittedly it might possibly be my HRM, whilst stating that it supports HRV, might not be good enough to really do a thorough job, but I'm still to be convinced as I've not seen any evidence from anyone else either. I'd like to be proved wrong though as I do like the idea of it.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 20th, 2024, 4:25 am
by Sakly
JaapvanE wrote:
October 18th, 2024, 2:45 am
AFAIK, intervals.icu and RowsAndAll use EPOC, as does Garmin (see https://www.firstbeatanalytics.com/en/f ... ning-load/). Might indeed what is looked for.
A quote of this site:
The Firstbeat Analytics engine transforms heartbeat data recorded during any workout into EPOC values. EPOC values accumulated during each training session over a rolling 7-day are tallied and used to provide a new perspective into the restorative and adaptive work your body is doing in response to training.
It is obvious the algorithm depends on the quality of the recorded HR data. When I compare HR data captured with my watch (Polar Ignite 3) and my belt (Polar H10), the data captured by the watch is absolutely useless. The watch underreports so heavily during workouts, that a good estimation isn't possible at all.
On the first hand, a good HR recording must be guaranteed, so a belt during exercise is a must. But even during lighter stuff like walking, daily activity stuff, HR data isn't much precise captured by the watch, so factoring in these data as well isn't giving a good picture of load and recovery.
After I realized the big differences in precision by watch and belt, I don't give anything about the metrics of these algorithms. Nice to see a trend or to use it a bit to play around, but not for serious planning of load and training.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 20th, 2024, 11:32 am
by Tsnor
Sakly wrote:
October 20th, 2024, 4:25 am
It is obvious the algorithm depends on the quality of the recorded HR data. When I compare HR data captured with my watch (Polar Ignite 3) and my belt (Polar H10), the data captured by the watch is absolutely useless. The watch underreports so heavily during workouts, that a good estimation isn't possible at all.
Pretty sure Garmin (FirstBeat) is using one of the HRV metrics. Agree completely that watches lose sync rowing, some worse than others. Watches also lose sync randomly throughout the day. If the watch can detect when it has good sync then it can get good HRV data.

Garmin and Fitbit/google also uses HRV data for sleep stages. Garmin also uses HRV for training readiness. Garmin and Fitbit both expose HRV data to end users too. They must have a way of getting clean HRV data from the mess the watch optics deliver.

I use an H10 also. Most people say the H10 sensor module is the best. Not in love with H10 belt life though but am sticking with polar pro H10 belts because polar claims they are more sensitive than standard polar belts.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 20th, 2024, 11:50 am
by Sakly
Tsnor wrote:
October 20th, 2024, 11:32 am
Sakly wrote:
October 20th, 2024, 4:25 am
It is obvious the algorithm depends on the quality of the recorded HR data. When I compare HR data captured with my watch (Polar Ignite 3) and my belt (Polar H10), the data captured by the watch is absolutely useless. The watch underreports so heavily during workouts, that a good estimation isn't possible at all.
Pretty sure Garmin (FirstBeat) is using one of the HRV metrics. Agree completely that watches lose sync rowing, some worse than others. Watches also lose sync randomly throughout the day. If the watch can detect when it has good sync then it can get good HRV data.

Garmin and Fitbit/google also uses HRV data for sleep stages. Garmin also uses HRV for training readiness. Garmin and Fitbit both expose HRV data to end users too. They must have a way of getting clean HRV data from the mess the watch optics deliver.

I use an H10 also. Most people say the H10 sensor module is the best. Not in love with H10 belt life though but am sticking with polar pro H10 belts because polar claims they are more sensitive than standard polar belts.
Ignite 3 also calculates HRV and displays it for sleep quality metrics. During sleep I am more convinced the data can be good, as no movement of the wrist and muscles occurs.
But all metrics based on training data are completely off the charts, as HR data is really not what it is in reality. I compared several gym sessions of the same type with belt and watch. They differ so much, that it does not makes any sense to calculate anything from the HR data at all.
Wouldn't recommend to buy a watch and use it for tracking of anything other than sleep. I'm not even sure, if sleep tracking is useful...
In combination with a belt, tracking of training could make sense, as data is absolutely reliable.

Re: Quantifying the "degree of difficulty" of a given erg session

Posted: October 20th, 2024, 12:00 pm
by Tsnor
Sakly wrote:
October 20th, 2024, 11:50 am
...
In combination with a belt, tracking of training could make sense, as data is absolutely reliable.
I tried tracking HRV data and resting HR data for 18 months using the H10 belt and EliteHRV. 3 minute reading first thing in the morning. I couldn't find any useful trends at all. The only time I saw significant movement was when sick or vaccinated where resting HR elevated. I gave up on it.

I use H10 OTW rowing, volleyball (wear belt, watch in the pocket), erging and cycling. Only use for the data I've found is when HR is unexpectedly high. Some days working really hard doesn't feel hard. It's good to know not to kill it the next day (if you believe in that training approach).