TymeWear is expected to launch their chest strap in June '25.
Intervals.icu Feature Request: Allow setting per sport zones based on minute ventilation (TymeWear data); IOW VT1/VT2.
“I believe that what we’re seeing could allow us to replace lactate threshold measurements in the field with ventilatory threshold measurements-making the process less invasive and more practical.” ~Stephen Seiler, PhD
In my opinion, this is a gamechanger.
From my experience, measuring FTP using a ramp test or a standard test requires being fresh, firstly, and it takes time to recover, so it’s not worth doing before a race ;). Additionally, it’s worth remeasuring every 4-8 weeks (in my case, after the TT Tune Up training on Zwift, I improved my FTP from 265 to 290 in 8 weeks). With this device, you can easily capture your thresholds by doing workouts on an ongoing basis and adjusting your zones.
When running, it’s best to go by RPE or run a 5k/10k at maximum effort from time to time, which again, requires being fresh and recovering afterward. So again, this TymeWear wins.
However, the tools provided by intervals.icu are also very reliable. Recently, I measured my LT1 using HRVlogger, and guess what? The difference in HR at LT1 was only 1 bpm compared to what was determined by intervals.icu and what was measured in the tests. The same goes for the CP pace curve; it excellently determines the lactate threshold pace (LTP), with a difference of only 5s/km (sic!).
For an amateur like me, the methods implemented in intervals.icu are sufficient, but that doesn’t mean I won’t buy TymeWear, as a gadget to diversify my training and monitor progress on an ongoing basis without the need to do threshold tests.
they dont do anymore the Subscription Shirts for ventilation?
@Milosz_P can you describe your process/protocol for find LT1 with HRVLOgger? did you try many time? reliable for you? i do with Moxy , but stop measure dfa-1
Dr Seiler explains in the FastTalk podcast that there were recording issues with the shirts. They discovered that a chest strap provides the most accurate data.
First of all, I wanted to point out that I do not like HRVlogger and I do not recommend this app, I wanted a refund from Google Play Store.
The files are sent in CSV format with strange timestamps, which makes them difficult to merge and upload to Intervals.icu., so to read the data I used Runalyze.
The process? Standard ramp test on passive treadmill.
I think the test was very helpful - it confirmed my assumptions and, thanks to it, I know now that I am training in the right zones. I will try to do another test to find LT2, or I will give up and order TymeWear 
I have become more interested in VT1 over the last year. As I used to think at best I did not have enough time for all that and of course it wasn’t sexy lol. So as I got back into riding after several years mostly off the bike, I was fat and slow and started doing LSD rides. Which I used to believe stood for Loathsome Sadistic Drudgery rides. I came to realize I was even doing them too hard and started focusing on where my breath broke VT1 and tried to stay around that. Funny thing happened, my but and hands, which used to hate these rides, were happier, because I was building up more power at the low end. Also my FTP went up not down, with no structured FTP training. Now I see this Tymewear and I think I may want that. I used to have power meters on all my bikes, but I am down to 2 out of 4 and I expect the one on the MTB to fail. I Can’t afford to add 2 power meters to the stable, but One strap, if it will help finally get a more accurate picture of Internal load, I am down with that.
Bumping this. Intervals.icu is the only platform that even captures this data, let us set our analysis by it also and the service is miles ahead of every other platform.
I got my Tymewear strap a couple weeks ago and the insights it gives you into your physiology is pretty amazing. For example:
My thresholds (fresh)
When doing back to back hard days, my cycling threshold will start to hit my cycling vo2max while HR will be on the upper end of threshold HR
When doing easy days after hard days, my Z2 power decouples from my VE than my HR.
Until you’ve warmed up, VE is higher.
VE is higher during higher cadence work.
While all these in the moment experiences are nice, VE is also super variable second by second, so having the ability to analyze time in zone would be super nice.+100 to this feature request
Did you see that the first steps are possible / creating custom zones:
Just saw this after this post!
How do you do this?