Long-time listener, first-time caller …
Is there a chart available in the activity record that tracks ‘load’ (or TSS) as it accumulates during the ride/race?
I may be missing it, but the only chart I see to quantify work done is through KJs. And yet, when it comes to performance, power is more determinant than HR.
Sure, it’s easy enough to roughly correlate the two measures.
But would be handy to know more specific measure of capacity at a “mechanical” level rather than “physiological” level (KJs based on HR, which can swing a little from day/day or week/week.)
Deep into a training block, KJ-measured ‘work’ will be lower than power-based TSS, while a day with an extra coffee (or a scorching summer race) will put KJ-measured work ahead of TSS.
Basically, I’m looking for a way to see (at a glance) performance with interval or in racing after, say, load (or TSS) clicks over 150 or 200 or whatever. Right now, I just set up intervals after, say, 2000 Kjs to get a sense of all-important fatigue resistance.
Since the load for every ride is tracked throughout the activity on Intervals.icu (both in aggregate and for each interval), would be handy to see the ‘running total’ displayed on the page for that activity, just the way it is for KJs.
Maybe that’s already available and I just haven’t found it?
Thanks,
Brenon
The kj is not a completely exact measurement since 2000 kj is not the same for someone with 85 kg and 350 w of ftp than for someone with 63 kg and 250 w of ftp, the “more correct” metric would be kj/kg, as for the TSS it also has its drawbacks since for the calculation the volume is more important than the intensity.
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You can’t do that currently but I have added that to the todo list.
Thank you, David.
It’ll be useful to know, both for the specific ride and as a point of comparison within a season or even seasons.
Measuring capacity is starting point for building capacity – and this will be a cleaner, less subjective measure.
Thanks again.
Brenon
@Brenon – there are two measures of work.
One is the work you accomplish, usually measured in kJ. This is simply your output = average watts x time.
The other is the effort that you put in, ie the energy that your body had to expend to produce that output. Outside the lab, this is usually measured by a HR-based formula, and in the English-speaking world is commonly expressed in kCal.
Outside the lab, kJ is measured more accurately than kCal. kJ is also very easy to calculate, once you know your average watts and the time.
The ratio between kCal and kJ is your body’s efficiency, its ability to convert energy into work accomplished. On average, this seems to be about 24%, but this does vary between individuals. It also varies slightly over time and is, to a slight degree, trainable.
TSS is, of course, different from both, being a weighted output measure that gives more emphasis to high intensity efforts than to low intensity efforts of the same duration.
So, when you say that you want to know how you can perform after a certain amount of effort, what measure of effort is the most useful to you? Effort in, work out or weighted work out?
For me, TSS (while still flawed) most accurately captures the ‘cost’ of racing/training because (as you note) it’s based on NP, which gives proper weighting to the high cost of intensity.
Other measures are co-linear (agreed) but TSS is usually what I look at when I want to know how hard a race was and how I performed there. (Which usually leaves me a bit despondent.)
As long as FTP is correctly established, TSS is the single most informative number I know to quantify work. I look forward to having this measure on Intervals.
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Did you end up finding a metric for this?
I think @david got tied up with other things.
Would still like to have it, but (obviously) life has gone on w/o it just fine.
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