Tymewear owners - worth it?

21

I really wanted to like Tymewear but ended up returning it after a month of use. My initial testing went well and the results lined up well with where I thought they were from relying on HR, power and RPE. But after that, I found that my VE and other breathing metrics tended too erratic. My VE was all over the place on Zone 2 rides both indoors and out for the same power output. I acknowledge that the readings were more inline with my testing values while riding indoors, but still found them to be too unreliable to base my training on, whether Zone 2 training or Zone 5 training. Outdoors was way worse and were likely affected by terrain and effort changes but the end result was lots of noisy data that said that I was spending way too much time way above my targeted zones. Those results did not line up with my RPE, HR or power data. Ensuring that the sensors band was consistently positioned and snugged made little difference to the results. I reached out to Tymewear and they could only suggest that I use the exact same slots on the strap and position the strap exactly the same on my chest. I don’t know if it was it a bad breathing sensor, or user error, or just growing pains of the Tymewear technology itself.

Tymewear handled my return promptly without issue but notably without an attempt to help me remedy the issues I was having. Bottom line is that I am still intrigued by the technology and willing to give it another go in a year or so to see if things improve.

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22

I’ve just been notified that my strap has shipped.
One fly in the ointment is that the accompanying email from UPS says it is delayed due to a customs declaration form not being included.
Finger crossed that it arrives soon and that I don’t have any problems with it

23

I received my Tymewear strap today and everything has gone well (after I put the battery in the correct way that is).
I did a short “test” up to threshold just to check everything was working as it should. I didn’t realise that if you save the test it automatically sends it off for analysis - oops.
After that I disconnected everything from my phone and tried my Garmin, setting it up how they said in the instructions. One bit of confusion is they said there were 2 Garmin IQ Apps/datafields - I only found 1 datafield but every thing worked fine, as did the chart set up by @Inigo_Tolosa on Intervals - Thank you.
Looking forward to doing a proper test when I’m less tired and can sort out some standard breakfast before it so when I retest there will be one less variable

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Only one data field is available for Garmin. Don’t look for more if you have already installed it.

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25

Where did find that graph. I just did a quick su max test just to see if things were working. I’ve got my results which are obviously garbage because I went no where near VO2max but can’t find that graph anywhere. Thanks

26

Been using since early September. It’s both great and not so great IMO.

TL;DR: I like it with some caveats… I’ve not had it long enough to determine fitness impact, but seems useful for testing, indoors, in a controlled environment/position and then using the extrapolated HR and Power ranges to try and guide the other 80% of my riding (note this defeats the value proposition of always being sure you’re in the correct zone… see below).

The strap design can be tricky - especially if you have a chest circumference that requires the strap extensions. I have a 45" chest so need to use one extension on each side of strap to keep breathing sensor in middle of back, but at their minimum extended length (so there are 1-2" extra ‘flaps’ of the extension straps that have to be tucked in under the main strap. I spend a fair bit of time in the gym and rowing and maybe it’s my chest/back anatomy, but fit has been problematic for me… I mostly forget it’s there after a while, but it’s much less comfortable than a newer Garmin for example. But the big problem is I get highly variable live and 15s average measurements during rides… every change of position (hoods, drops, standing, etc.) and I can easily see massive changes (20-40% VE), even indoors. Heck, reach for a water bottle, take a deep breath, and VE spikes from 60 to 100 in data recording. And even after initial position change settles, VE readings are different for each position. I suppose you could argue that should allow me to explore the best position as it relates to breathing, but come on, I’m a middle-aged dad trying to get 10 hours a week on the bike and a few races a year under my belt. So that raises the question: which VE is correct depending on position - does position influence breathing which ultimately reflects underlying metabolic zones (i.e. are my zones different on hoods/climbing/drops - which is ‘right’)? Or is the position just a reflection of my musculature changing the fit of the strap differently and creating a ‘bad’ reading from the test position I used? I don’t know, but it feels like a crap shoot at times. And I think if you watch the video of the Visma coaches on Tymewear’s website you can see this too when they all agree is a groundbreaking technology but they’re still understanding how best to use it.

I’ve had some technical issues too… my first test at the beginning of September took four days for results to be returned… not that big of a deal, but then my second test a month later was ‘stuck’ in analyzing mode on their app for a week… I eventually sent email to customer support (via the order confirmation email… their IOS app links to support didn’t work, had to submit a screengrab, but as soon as you go do that, the text of your ticket disappears. A day after that, my test results suddenly populated, but with missing top-end values for Z5. Their support tech told me there was a data corruption event and apologized and told me the next test would have those values. Again, no big deal, but pretty beta-level.

Recommended workouts… To get your ‘ranges’ and inflection points, you take a ramped breathing test. That’s fine, but it means your breathing is generally increasing and consistent until you blow. However, if you do one of their VO2Max interval workouts, by breathing rate and suggested interval durations, I can never hit their targets because in a 30/15 or 40/20 interval your breathing rate is unlikely to be elevated long enough to (until maybe very end) to register as your top breathing rate (as seen during the ramp test). At least if you do these more traditionally by power… but I don’t see how you can realistically do at shorter interval workout by VE alone since it’s a bit laggy like heartrate and the typical on/off ranges will need to be bigger than their workout shows in my experience to both hit the suggested peaks and recovery targets. So you can do their interval workouts over and over, see your power and HR and RPE clearly in VO2 training territory, but if VE wasn’t in those same ranges/durations the app will keep indicating you have a gap there and recommend more VO2Max workouts. Which I guess begs the question… is VE the right measurement for high-intensity (short) interval training? Or is VE the true measure and my 30/15s with power need to be more like 60/120 to get the breathing targets to align. Again, IDK.

The last thing I’ll note isn’t really related to the technology, but it the protocol/programming recommendations and what they did to my brain… my test results indicate that my VT1 is too low (relative to VO2Max) and best thing to do to improve VO2max is to increase my VT1 threshold by a whopping 23% and to do that I need to spend 95% of my weekly training sub VT1, which practically speaking makes ‘free riding’ outside impossible (I live in Idaho and there’s just no way to get 8hrs/week <2.5w/kg on trails or roads for me… maybe if I moved to Kansas). The upshot is I’ve actually started looking into some ebike options, which i never thought i’d do until I’m “old”. So, although this may be the correct intensity I should be training to get better, it’s pretty demoralizing and a bit of a mind fck… I used to ride outside in my otherwise-tested Z2 for power/HR and have fun, now in back of my mind I’m always thinking I’m going too hard (especially if you recall Inigo San Millan’s advice just a year or two ago where he talks about how it takes your body 30+ minutes to return to proper Z2 metabolic state if you go too hard in a ride, regardless of what your heartrate and power indicate). Sigh.

So, long post. Cool tech with some implementation challenges still. Worth it if you like data, but beware, sometimes ignorance really is bliss.

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27

I agree with everything you’ve said. I’ve just got mine and did a quick threshold test (labelled as such) to just check everything was OK and it went off to then for analysis by mistake. It came back with garbage numbers as you would expect but so much for being checked bt a human though.
Unfortunately it looks like doing loads of sub VT1 riding maybe necessary to get a deep and lasting base. I got an e-bike so I could easy riding off road on the hills away from traffic ( I live in the crowded NW of England) Its ben a game changer for me. It also has given me a glimpse of what it must be like to be Pro riding up steep inclines. One way to check San Millans advice I suppose would be to see how long you VE take to drop to sub VT1 levels after hard intervals. Other people more knowledgeable than me have said it takes no where near that amount of time but it it does depend on the intensity and overall duration I think with it taking longer as overall fatigue builds.

I am almost certain I go too hard for too long when I’m training and this is the main reason for me plateauing and I hope this bit of tech will help rein me in.

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28

I have a Lactate Pro and experienced the same mind F’#ck with LT1 testing early in my return to competition. To effectively stay in that Z2 threshold I rode the flattest routes around me.

If the Tymewear is giving the same measurements not sure its worth the extra $300 for me.

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It’s not the same for everyone, as he says it depends on your ability to clear lactate. Also, he says that if your mitochondria has to choose between lactate and fatty acids, it will choose lactate as it can enter the cell directly whereas fatty acids has a multi step process to convert to ATP. Fat as a fuel source is abundant, but extremely inefficient compared to glucose and lactate. He also believes that you need to ride at the top of zone 2, which is at fatmax. At the top of zone 2, you have a limit too, based on your ability to hold that power for a specific duration.

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30

I watched the founder’s interview closely. He clearly confirms there’s lag in the data. Power gives the fastest and most accurate readings, but it’s an external output. Heart rate has a bigger time lag. Breathing sits somewhere in between. So in my view, with intervals under one minute, breathing won’t keep up and won’t be captured properly. That’s why you’re right when you don’t see VO₂ work in the breathing metrics, even though you clearly hit it by RPE and power.

Yes, the tech is raw but promising. I’ve ordered it, I’m waiting for delivery, and I’ll test it. I use lactate data in almost every session and I know my lactate thresholds quite well; they differ a lot between sports (running vs cycling). I’m very interested to compare lactate metrics with ventilation.

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31

I’ve a tymewear strap for 2 weeks now. So far it is not very useful.
First, there seems to be a real problem with me and the “calibration”. It read very reproducible values in general, but the thresholds I get are not useful, i.e., wrong. I have done 2 ramp tests so far, albeit the first one with a slightly altered protocol. The second with the original protocol, but I did not reach “VO2max” (nor my max HR) due to peripheral/muscular fatigue before getting there due to the long (starting at 70 W) and slow (20 W/3 min) ramp.
The first test gave very clearly too high thresholds, the second one gave power targets for the thresholds that were still a bit high … but the ventilation numbers (volume/min) are definitely way too low:-o
I have done two very clear outdoor GA rides of 3:30 h and 2.15 h.
The first was really at the upper end of Z2 according to power (derived from FTP, from power-profiling CP, as well as from athletic.ai), HR (from experience and from threshold tests), and feel/RPE. tymewear ventilation put this pretty much entirely >Z3, i.e., into Z3 with a non-negligible contribution from Z4:-o
The second was a real easy ride today, with power, HR, and feel really in the middle of Z2. Still tymewear put’s much higher with TiZ 32 % Z2, 37 % Z3, 30 % Z4.

The ventilation measurements as such do in fact look good and very stable over the different rides I did with the strap. But the thresholds it detects for me are completely off.

The software is very rudimentary, too, and analyzing the data is cumbersome. This is partly related to me not having a Garmin (Wahoo user so far) and my indoor software also not supporting the strap yet. And the tymewear software is really as stable/useable as their current message to extend free use until end of 2026 suggests;-)

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32

Have you tried looking at the data yourself to see if you can identify your thresholds. Although they say a human being verifies the automatic setting of them, I very much doubt that is happening at the moment due to the level of customer support required with this new product. I read this article about thresholds and on the VO2 master site and determining where they are does not appear to be straightforward.

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33

I had and still have, generally good and constructive, back and forth with their technical support. And they have re-checked and even re-analyzed the tests.
The real issue is that my ventilation traces do not look as they expect…
I did the tests on the indoor trainer in a standard setting I am using for years, nothing special while doing these, no different from power profiling I did 4–5 weeks ago that worked well and gave very reasonable numbers…

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34

Thank you for the article; it clarified a lot for me. I did the test, and while waiting for the results, I analyzed the graphs. They almost matched the results I got from the test. Moreover, they also aligned with my assessment of the lactate curve (I also measured lactate at each stage).

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I’ve already shared some feedback on one of the forums about using the Tymewear sensor. I’ll post it here as well, and I’d really like to get some pushback or discussion around my observations and conclusions.

Just to be clear upfront: I’m not a professional athlete and I’m not a cyclist. My main sport is cross-country skiing. That said, I enjoy cycling and use it as part of my off-season training.

I’m 50 years old, I work full time, and I have two kids. Over the last 12 months my average training volume has been about 7.5 hours per week. My PBs are a 1:29 half marathon and a 2:21 ski marathon.

I consider lactate and RPE to be the most practical and valid markers for assessing internal load. In every training session, I monitor and calibrate the stress load using lactate values, both in hard and easy workouts. I define anchor threshold values for power and heart rate based on lactate results. Regular tests also allow me to track power progression over time, roughly once every 3–4 months.

At the same time, since I started using Tymewear, I use ventilatory thresholds for online monitoring of metabolic internal stress during training. In this approach, power/pace and heart rate are secondary and used mainly as reference.

Below is a comparison of lactate thresholds and ventilation.

First Tymewear test — 18/11

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Lactate
• LT1: Power 185 W, HR 145
• LT2: Power 225 W, HR 158
• Max Power: 270 W
• Estimated VO2: 44.4 ml/kg

Tymewear
• VT1: VE 46, Power 170 W, HR 139
• VT2: VE 70, Power 229 W, HR 159
• VE VO2: 120, Power 267 W
• Estimated VO2: 46 ml/kg

Tymewear recommended focusing on VO2 and Z2 improvement, which I tried to follow during the next month.

Zone 2 calculated from Tymewear ventilation and power data (VE 46 / Power 170 W) was slightly lower than Zone 2 derived from lactate data (185w). This was confirmed in subsequent training sessions.

  • During the month, my easy sessions at VT1 ventilation level (VE 46) resulted in average power well below LT1, around 130–150 W, with lactate about 1.1–1.3 mmol. This is significantly lower than my LT1 power (~185 W).
  • My hard VO2 workouts at around 270 W showed ventilation values between 75 and 116 (average ~95), with lactate above 7 mmol, clearly in the VO2max domain. At the same time, average heart rate during intervals was around 160 bpm, which should correspond to LT2/VT2. In this case, lactate and ventilation confirmed the internal load, while heart rate did not increase further. From this, I conclude there was likely some suppression of the nervous system.

Second Tymewear test — 16/12
after:
Total training time: 37.5 hours (~7.5 hours per week), including:
• Cycling: 15 hours
• Running: 7 hours
• Skiing: 9 hours
• Other (swimming, strength): 6.5 hours

Cycling volume: 15 hours
10 sessions total:
• 4 HIIT sessions, RPE 8–9 (VO2)
• 11 easy sessions, RPE 1–3

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Test results

Lactate
• LT1: Power 186 W (+1 W), HR 141
• LT2: Power 235 W (+10 W), HR 159
• Max Power: 290 W (+20 W)
• Estimated VO2: 47 ml/kg (+1)

Tymewear
• VT1: VE 54 (+8), Power 207 W (+37 W), HR 147
• VT2: VE 74 (+4), Power 232 W (+3 W), HR 159
• VE VO2: 144 (+24), Power 288 W (+21 W)
• Estimated VO2: 49 ml/kg (+3)

Tymewear recommendation: focus on VO2 and Z4 improvement.

In this test, as in the first one, I observe very similar threshold values at LT2/VT2 and VO2. However, the power values seem overestimated to me. At the same time, VE 54 is likely very close to LT1 power, around ~180 W or slightly lower. Based on only two tests, I would conclude that Tymewear’s threshold values and VO2 estimation are very close to laboratory measurements, while VE/Power at low intensity (first threshold) may vary somewhat.

My conclusions

Tymewear estimates of power and heart rate can differ significantly. Power and heart rate thresholds represent the upper limits of training zones and are more of a reference than a true anchor for training planning. Ventilation, in my view, reflects internal load quite accurately. My intensities at FTP (LT2) and VO2 levels clearly fell into the corresponding ventilation zones, while my easy sessions stayed below LT1, which I see as positive and on the safe side.

In my training, I use three criteria:

  1. Lactate-based LT1/LT2 as anchors for power and heart rate thresholds and for progress assessment
  2. Online VE as a red line for internal stress during training
  3. RPE plus control of cardiac drift

It is important to understand that no test is ever 100% accurate, even in a laboratory with gas analysis and lactate measurements. These are just tests. Thresholds and values are not fixed forever. I have had sessions where training felt very hard, but lactate consistently showed intensity well below the first threshold (likely due to low glycogen). I have also had sessions where I could not maintain heart rate in the target zone, while lactate was clearly above my threshold values (central nervous system fatigue). At the same time, I have had workouts where, to maintain the same ventilation intensity, I had to reduce power by about 20% from the beginning to the end of the session.

And a few subjective observations from this month. I improved my maximal power, which was confirmed by testing. Easy sessions with ventilation control became even easier, and my general feeling is that I get tired, but I can repeat the same training the next day without difficulty. My VO2max workouts were very hard, extremely hard. However, I could see that ventilation during the intervals was clearly in the VO2max zone, while heart rate did not reach the commonly cited 95% of maximum. I honestly cannot imagine how hard I would have had to push to reach 95% of my maximum heart rate.

I will continue to explore this further. For now, the ability to monitor internal stress online looks very promising to me.

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36

Yes this is so good … :slight_smile:

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Measuring ventilation thresholds is a refinement. Instead of just having FTP, and derive all else as a percentage, you now have two or three more anchor points. Power is about one’s output, while breathing is about “internal effort”, because you are breathing more to exhale CO2. VT is not about replacing power and its ecosystem, but by linking VE and power through tests every now and then, you can improve your power calibration versus only relying on FTP. I mean, when cycling power was introduced, some riders were saying: “I have successfully trained all my life by feel, what do I need power for?”. It’s all true, and if all you are ever in for is a healthy ride, any system of data collection (by feel, by power, by talk test, by ventilation, by heart rate) will give you enough guidance.

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38

Thank you for the report!
On that point, I am having the same problem – typical VO2max workouts, neither 4 x X min nor 30/30s / 40/20s / etc. get me even well above 90 % max HR… which I routinely reach in group rides (trining “races”) going up a little hill after 2…3 h.
(I am still wondering if the former has to do with muscular deficits limiting power.)

Re Tymewear testing: how well does your data look? For me, it is often difficult to analyze due to bumps, maybe from drinking or similar “events” and clear trend lines, thus clear thresholds are hard to see. Although the Tymewear guys, at least when initiated for a closer look, seem to get very reasonable and useful values out…:wink:

39

There can be many different reasons why heart rate during workouts may not reach maximal values. For me, the key indicators of workout quality are RPE and lactate. Right now, I am also exploring intensity control using ventilation data.

Regarding the idea of being muscle-limited: some time ago, a knowledgeable coach suggested that I do a 5-second all-out sprint. In my case, it was 800w. Using the rule of thumb “potential FTP ≈ 0.4 × 5-second power,” that would imply an FTP of about 320w. Since my actual FTP is around ~240w, I am clearly not limited by muscular strength. In my case, the number one limiting factor is oxygen delivery: stroke volume and hemoglobin level.

As for ventilation testing: noise in the data is normal and expected. But even with a simple visual review of the ventilation graph, you can clearly see the break in the linear upward trend, and you can estimate the threshold value quite accurately, usually close to FTP.

Here is a simple example where you can visually see the breakpoints in ventilation.

image
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And this is a table of threshold values provided by Tymewear

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Based on two tests where I also used lactate, the BP point identified by Tymewear is located slightly above the first clear lactate rise, around LT1.

41

You’re very welcome, but I don’t think this “rule” is a golden one. It’s just a rough reference that can help you better understand what might be limiting you.

I’ll share my view on performance limits. In simple terms, there are three main ones:

  1. Endurance (aerobic power and capacity). This limits about 90% of recreational athletes.
  2. The blood transport system: stroke volume × hemoglobin mass = how much oxygen your blood can deliver. You can calculate your potential VO2 and compare it to what you have already achieved. This is my case.
  3. Muscle mass. This is likely your case.

In any case, strength training won’t hurt anyone—especially recreational athletes.