We react to the 2025 review “Nutritionally Relevant Technological Advancements in Professional Cycling” and give practical takeaways on the most talked-about devices athletes are wearing right now.
Video Transcript
[00:00:00] Chris Case: Hey everyone. Welcome. I’m Chris. This is Trevor Fast Chats. We just stepped out of the studio to record a lengthy episode on. Technology use in nutrition and workload. Um, some big names on this review paper, the title being
[00:00:17] Trevor Connor: nutritionally relevant. Technological Advancements and Professional Cycling.
That’s a mouthful, but they did this for the UCI to look at these different devices that athletes are starting to wear. It’s.
[00:00:29] Chris Case: We’ve done this stuff in the lab for, for years, decades, in some instances. Now we’re in this age where we wanna bring technology out into the field and sort of replicate that. But there’s mixed results.
[00:00:41] Trevor Connor: Yeah. This is really important. All these things that these devices are measuring, we can measure in the lab and we can measure effectively in the lab. So this is about can we measure this out on the road, um, take it to the athletes. And I would say the overall conclusion of the study is. Or the review is, this is a noble quest one that we need to take on, but we’re just not there.
Yeah. Most of these devices, the complexity of the situation, the environmental factors, does your clothing touch it? What impact does sweat have on it? Sunlight have a, mm-hmm. All these things that you don’t have to deal with in the lab, just prevent them from being able to say, yeah, these devices are truly ready.
[00:01:25] Chris Case: Let’s, let’s dive in. Mm-hmm. Um, let’s start with continuous glucose monitors have been wildly popular in a way in the recent years. What do they say about these things?
[00:01:35] Trevor Connor: Yeah. And very quickly, we covered all these in a lot more detail in that episode. We’re just given the, the quick takes on each here. Yeah.
And continuous glucose monitors really important to understand. They’re now banned, so you just can’t, you can’t use ’em. And unfortunately, there have been athletes who didn’t know this, wore them in races, they won and had their results stripped from them. Yep. Uh, but even if they weren’t banned, this is just not a device that I would recommend and they didn’t recommend in the review either because they are measuring interstitial fluid, um, and trying to give you an estimate of blood glucose levels.
But interstitial fluid is 15, 20 minutes behind. So if you’re using this out in a race to tell you when you should be fueling, you are being told, Hey, you should have fueled 20 minutes ago, too late. Now you’re bonking. Yeah. It’s just, it’s, they are life changing devices for diabetics. Um, I just, the, the review said this, I, I am in full agreement.
I just don’t really see that value out in the road.
[00:02:36] Chris Case: Mm-hmm. Agreed. Let’s, let’s move on to sweat and there’s, there’s two different measurements we’re talking about here. One being electrolytes in real time, and then we’ll get to it, lactate.
[00:02:49] Trevor Connor: Yeah, so the sweat analysis that’s been for electrolytes that’s been around for a while, um, and it is a valuable thing to get done in a lab because some of us sweat a lot of electrolytes, some of us don’t sweat much at all.
And you really wanna know that when you are figuring out your mixes for racing and, and for training, right? Um, this out on the road device, they said surprisingly is pretty good. Pretty reliable, pretty accurate. But their response, and you’re gonna see this in some of the devices, is even though we can measure this, so what, what’s the value of this?
What is that gonna change when you’re in the middle of the race, knowing that you’re sweating a lot of electrolytes.
[00:03:28] Chris Case: Mm-hmm.
[00:03:29] Trevor Connor: Right. You know, the other thing that pointed out too is it only gives you the major electrolytes. It doesn’t give you a lot of the other mm-hmm. Nutrients in your sweat that you might wanna know.
Yeah. So accurate. Uh, usability. Questionable. Questionable. Yeah. You know, good thing to get done in the lab or to, to measure once, but seeing it out in the road, not so much.
[00:03:50] Chris Case: Right. And then, and then sweat lactate. And interestingly, they, they found some value here.
[00:03:56] Trevor Connor: This one surprised me. I was expecting them to just kind of go, are you serious?
Like, why are we trying? But they, so they’re trying to use lactate in the sweat to get an estimate of blood lactate levels. And they said, this is so far from the research, uh, surprisingly showing promise, but with a, a big asterisk of this is a very new device. There’s only been a few studies, so it’s very preliminary data.
Mm-hmm. So promising. But we really need to have those. Further studies done to say, yeah, this is something that you can trust.
[00:04:30] Chris Case: Yeah. And by the way, if you use any of these things, let us know in the comments what you think of them. Yeah. What, what quirks you’ve found, if you found it useful or not. Uh, the next one we should talk about is one called Muscle Sound.
It’s an ultrasound device that looks at glycogen levels in in muscle tissue. We have personal experience. We’ve had it used on on us. Up at the University of Colorado Sports Medicine and Performance Center, Dr. San Milan was on one of the first papers to publish results on it. It looked promising. Yeah.
You had
[00:05:05] Trevor Connor: a lot to say about this on the episode in
[00:05:07] Chris Case: recent years that that has not been confirmed with further, further research and they kinda, they kind of looked skeptically at this technology.
[00:05:18] Trevor Connor: Yeah, no, it was interesting because, I mean, this would be great technology. Before this, the only way we could measure, uh, glycogen levels in your muscles is to take a biopsy.
Mm-hmm. Which is literally taken out a fairly sizable piece of your muscle, which most athletes aren’t interested in having. That’s right. Done. Um, so to be able to have this non-invasive way to say, yeah, your, your glycogen levels are replete or have been depleted would be highly valuable. Um, and this device, initial research was, was showing promise.
More recent research that’s looking at all these different variables, different scenarios, like when you’re fatigued from a training camp or the impact of your diet on, um, uh, on these devices. Not so, not necessarily on the glycogen, but your, your diet can affect how it measures glycogen and give you a, a bad value.
Sure. So you’re just seeing, when you start looking at all these different variables that are real factors in people’s lives. You start getting less inaccurate results from the measurements. Mm-hmm. Which is unfortunate.
[00:06:21] Chris Case: Mm-hmm. And then there’s another device ultrasound as well that looks at muscle fiber type and that might have some val give valid results.
But the question is how do you use it again? Yeah.
[00:06:32] Trevor Connor: So this one, they said it, it seems to be pretty good results. Um, but again, how do you use it? Because yeah, you can measure, go, Hey, I got a lot of slow twitch and not very much fast twitch. Nothing’s gonna change for a long time, so That’s right. What do you use with that beyond that point and, and how does that affect your training?
Mm-hmm. Uh, but they pointed out it could be used really well for talent identification. Yeah, absolutely. Fact of the matter is very elite endurance athletes have a lot of slow twitch muscle fiber. Right. So there is potential uses there. And then Chris, another one I know that you love, which is probably the last one we should touch on is skin temperature devices.
That’s
[00:07:12] Chris Case: right. Yeah. The core temperature device, um, is looking at skin temperature to approximate core temperature.
[00:07:20] Trevor Connor: Right. It calculates core temperature based on skin temperature. Yeah. And again, they found in the lab it was pretty reliable, but again, you get out on the road and. What if you have a shirt sleeve over it or you don’t have a shirt sleeve over it?
Mm-hmm. What happens if the sun’s beating down on all these other factors once you get down the road? It’s much, much harder to estimate core temperature from these skin temperatures, but they did point out there is still value in getting skin temperature measurements. That’s data that you might be able to use such as one study that showed that you seem to see.
See optimal training adaptations. Uh, when your skin temperature’s in a certain range. Mm-hmm. Mm-hmm. And we read an article that Todd CIA’s team has gone out and bought core device, these core temperature devices, um, even though they’re not sponsored because they find it really valuable data.
[00:08:16] Chris Case: Yeah. I think that you’re gonna see that more and more with professional teams, as Dr.
Seiler said in our 400th episode. Teams at the elite level are essentially demanding that the lab come to them. Right. And so. Teams might get ahead of the curve, if you will, from the published research, right. And understand things that scientists have yet to find out.
[00:08:38] Trevor Connor: They are hiring their own scientists to study this stuff and they are not publishing the results.
’cause it gives them a competitive advantage. So they did say in this review, there may be potential value to that skin temperature measurement, but we don’t know what it is yet. But it’s quite possible that Todd’s team has been doing those studies, they’re not publishing it, and they have found a value.
Yeah.
[00:09:00] Chris Case: Yeah. So again, this is just a short review of some devices, some good, some bad, some mixed. It’s a noble quest to try to bring the controlled environment of the laboratory out onto the road. It’s gonna be challenging.
[00:09:15] Trevor Connor: It’s gonna be challenging. I think the overall conclusion is, please keep trying to do this, but we’re not there yet.
[00:09:21] Chris Case: Yeah. Very good. Well, if you like this content, give us a like, subscribe to our channel. There’s more to come.
