Something I’ve mentioned on here numerous times is my feelings on over reliance of made up metrics like TSS. My common drum to beat is how a 100mile steady training ride gave same TSS as a marathon race that left me walking backwards downstairs for a week. Also I think I mentioned, sure it was from IMJ, where someone said they cut swimming as it was making them “detrain”

I know its just 144 character soundbite but more experts are sharing this opinion. The only metric you can accurately believe is what your body tells you


100% agree. It often seems like an end in itself.

As an aside, I really like Joroen Swart.

1 Like


1 Like

Likewise. I double taked at first glance of the post that he was needing to apologise to him, but reading the thread looks like all agreeing that just chasing TSS is meaningless.

Was lucky enough to be able to go to Cape Town for 3 weeks as a student to observe Dr Swart and their sports medicine practice. Can’t really give enough superlatives for my experience there, I still feel years/decade’s away from reaching that.


Some scientists are way too “scientific” if that makes sense but the likes of Swart and Seiler use the evidence in the right way to guide and inform, not dictate

1 Like


Totally agree. As an example I saw him do a bike fit for a pro cyclist with an ischael hygroma. In the lab with all the cameras and sensors etc, but he did it 90% by eye, tape measure and quick angle measurements, and then turned the fancy kit on just to check and consider tweaking if he agreed with it.

1 Like

Resurecting this tread. Here are my Training Peaks numbers from “Operation Sandbag”, more commonly known as Ironman Wales

I have used HR TSS on the bike as my watch didn’t connect to the power meter, and the Garmin head unit battery went flat after 165km - however, TSS based on power was 290 after 165km


after @JibberJim 's interesting post on the other thread, knock 180 off the bike (6 * 30) TSS and it seems to correlate much better.


And Kona last year


That makes sense.

My Intensity Factor (IF) in Wales was 70% which is bang on plan

1 Like

I feel duty bound to say #humblebrag for all the lurkers out there :wink:

250 for the weak (ie me)
260-280 is the generally accepted AG goal (ie you lot)
290/300 is for the exceptional (elite IM runner)

But as I’ve said many times in the past these are for hindsight not for planning really. You don’t really know what your TSS will be on race day unless you have a perfect day. Also TSS has some variability built into the variance in power meters and environment, it’s a ball park thing. 260 being only 4% more than 250.