Not sure if that’s it in this case, I’m comparing TSS as calculated by TrainingPeaks to 2 figures calculated by TrainerRoad, which we now know don’t match exactly. Also such small samples, could be just rounding error. But yeah just by pure math alone if I understand it right, averaging the (whole sample set)^4 and then taking ^1/4 of that vs. doing it to splits and then summing those up would yield such results. It is some pretty simple math and there’s nothing magic about it, one could use ^5 instead of ^4 and get more “reward” for hard efforts in TSS calculation for example. This all strikes me as pretty un-scientific but good enough to make some sense of my training.

Here’s a simple demonstration of this math. Say you had a 2 minute ride with 30-second average power values of 2, 3, 4, 5. Let’s compare, calculate NP once for the whole ride, or calculate each minute separately and add those up. We get 7.9 for the single span and 7.22 for the sum of two spans.

… and the more un-even the intervals are in power, the more difference we’ll see in those two calculations. These two are almost identical so the sum of two splits is almost the same as doing the math for the whole span:

vs.

Ok I’m done geeking out on this. Sorry about that

You’re correct, that was a mistake to state that. IF and TSS are functions of FTP however. It doesn’t take away from the larger point that these measures are inappropriate for this type of ride.

What makes you think that? TP gives that ride a TSS of 33, which aptly classifies it as what it was, i.e., a weak sauce recovery noodle. TR’s screwed-up calculation of a TSS of 199 doesn’t change that.

To me it looks like TSS is Ok for this type of thing, even though overall it seems too simple of a model to really have any real accuracy. Sure the training load is non linear with power, but assigning a certain fixed scale that is supposed to work the same for everybody seems rather optimistic. But hey, it’s simple and it’s something everyone seems to agree on.

If I was trying to go for some serious high intensity intervals going after my coffee, then TSS would potentially become very inaccurate by the nature of the formula plus given that the top end power doesn’t correlate so well with FTP.

Makes me think that TSS would be quite a dodgy number to go by for say a training mountain bike ride in the park using technical trails where power would be super choppy, almost like doing high intensity intervals.

Don’t people use NP from crits to estimate FTP? How is that any different?

That’s a strange way of saying “I don’t know”. Power meters should work all the time, regardless of if you’re doing a race or a charity ride or a commute or a leisurely spin.

Powermeters are training tools. If you’re not actually training, don’t press the “on” button.

31 posts – many of which have come from me, yes – about an f-ing coffee run.

So what? This is a social platform, if you want to judge and criticize people because they hit record for a cafe ride or ask questions, maybe this isn’t the place for you.

Have you tried doing the same ride? Keeping the same low intensity to see if this happens again.? There could be some false data hidden in the file causing this anomaly. And yes I believe you should use power on all of your rides.

@RLucky82 no point in trying again, it is pretty clear where the issue is from looking at the same ride split in two.

@RobertK, imagine a grand fondo ride where you hit lap button like I did every time you atop at aid stations. If the gap like that indeed creates a skew in TSS, you’ll get somewhat incorrect (higher) TSS for your overall fondo depending on how much time you spent at aid stations.

Plus, yea, I don’t see anything wrong with having all rides recorded, it’s just a habit and a useful one. My rides to work aren’t training but they sure add a lot to the training load.

I can’t see how this is a productive contribution to the discussion. To me, this question increases everyone’s understanding of how software interprets power data, which is a useful conversation. People should employ their kit investment anyway they like. I record every ride with power, regardless of its duration or purpose, and I don’t think i’m doing it wrong…

I’ve heard NP from a road race being used for that. Doing the same with a crit would probably end up with too high of an FTP from all the surges (for a typical crit, anyhow). They’ve mentioned this phenomena in some episodes as NP busters if I recall correctly.

It was a rhetorical question.