State of the Peloton 2025

[Fester]

How is higher hematocrit useless? It's the whole point of blood doping!

I'm guessing you didn't look up "carboxyhemoglobin".

Come on guys, you have the world's knowledge at your finger tips.

 

[kingjr]

Seems unlikely:
“In all vertebrates harbouring hemoglobin, this protein is transported within erythrocytes. The volume percentage of erythrocytes in the blood is called hematocrit (Hct). The higher the Hct, the higher is the blood transport capacity for oxygen.”

https://www.researchgate.net/profile/Michal-Sitina-2/publication/381001129_Optimal_hematocrit_theory_-_A_review/links/668b799a0a25e27fbc2fd4b5/Optimal-hematocrit-theory-A-review.pdf

Yes, but the point, as I understand it, is that high levels of carboxyhemoglobin can counteract these benefits, at least in the short term. So you'd first have to use it for an extended period, which comes with considerable health risks, and then stop using it; and even then, it's unclear whether there are any actual benefits compared to regular altitude training.

Cycling performance determinants improved more with CO inhalation at moderate altitude compared to sea-level training, whereas there were no differences in submaximal and maximal performance measures compared to moderate-altitude training alone.

https://pubmed.ncbi.nlm.nih.gov/39236115/

 

[Netserk]

Yes, but the point, as I understand it, is that high levels of carboxyhemoglobin can counteract these benefits, at least in the short term. So you'd first have to use it for an extended period, which comes with considerable health risks, and then stop using it; and even then, it's unclear whether there are any actual benefits compared to regular altitude training.

Cycling performance determinants improved more with CO inhalation at moderate altitude compared to sea-level training, whereas there were no differences in submaximal and maximal performance measures compared to moderate-altitude training alone.

https://pubmed.ncbi.nlm.nih.gov/39236115/

In a Danish cycling podcast/TV program, Lars Nybo of Copenhagen University suggested a protocol with a higher frequency than in that study (as CO is so short-acting that you don't stress your body and provoke a physiological response enough with a safe dosis if you only do it a couple of times a day).

Brian Holm tried it out, in the manner done for measuring Hb (he gets to a concentration of 5-6 % here):

 

[kingjr]

In a Danish cycling podcast/TV program, Lars Nybo of Copenhagen University suggested a protocol with a higher frequency than in that study (as CO is so short-acting that you don't stress your body and provoke a physiological response enough with a safe dosis if you only do it a couple of times a day).

Brian Holm tried it out, in the manner done for measuring Hb (he gets to a concentration of 5-6 % here):

Do you know where I can find some more details on this in text format? Thus far, I can only find the podcast, and I don't speak Danish. And there's a 2022 article by Nybo that only seems to address altitude and heat-acclimation training, however.

Or if you can tell me where the relevant passage is in the podcast, I can do some speech-to-text magic

 

[Netserk]

Do you know where I can find some more details on this in text format? Thus far, I can only find the podcast, and I don't speak Danish. And there's a 2022 article by Nybo that only seems to address altitude and heat-acclimation training, however.

Or if you can tell me where the relevant passage is in the podcast, I can do some speech-to-text magic

After 19 minutes in the video:

Mielke: Er det sundt, det her?

Nybo: Det er ikke usundt. Det svarer til at ryge nogle cigaretter i den kultiltemængde man får, men man får ikke alle de andre stoffer ind og så videre. Og man kan sige at Brian havde allerede i hvile 1 % af hans røde blodlegemer, som havde kultilte til sig. Han bor i byen, han har røget lidt smøger i går, så der er lidt bundet. Nu øger vi det til 5-6 %, og det vil han så have, så når vi kommer til at sidde ned bagefter og snakke, så vil Brian have det lidt forhøjet, så hvis han gik direkte ud at cykle, så vil han godt kunne mærke det. Men når han skal cykle i eftermiddag, så vil han have åndet det ud igen.

Mielke: Så vil han være flyvende, eller hvad?

Nybo: Nej, for der er ingen effekt af det. Men hvis vi tester ham lige efter, at vi har målt det her, så vil det være hæmmende.

Mielke: Der vil være en effekt, hvis han gjorde det dag efter dag?

Nybo: Han skulle nok gøre det her, hvis han gjorde det her kun, den her så lille mængde, som vi giver her [Netserk: 1 mL CO per kg body mass], så vil mit bud være, at han skulle gøre det 5-6 gange om dagen i tre uger for at få en effekt.

Mielke: Men hvis I så skruede den op? Det var det, du nævnte før.

Nybo: Ja, så kan man måske nøjes med 4 gange om dagen eller 3 gange om dagen. Men du er nødt til at gøre det flere gange om dagen, fordi det kun er forhøjet i kort tid, fordi han vasker det ud igen. Og specielt hvis du så er cykelrytter, der er trænet, så ånder de jo mere, så ånder de det hurtigere ud.

Mielke: Og det er det, der så kan være præstationsfremmende, hvis man gør det systematisk?

Nybo: Ja, det er det, nogle studier har vist.

Mielke: Is this healthy?

Nybo: It's not unhealthy. It’s equivalent to smoking a few cigarettes in terms of the amount of carbon monoxide you get, but you don’t inhale all the other substances and so on. You could say that Brian already had 1% of his red blood cells bound with carbon monoxide at rest. He lives in the city, he smoked a few cigarettes yesterday, so there’s already some bound. Now we’re increasing it to 5-6%, and that’s what he’ll have. So, when we sit down afterwards and talk, Brian will have slightly elevated levels. If he went straight out to ride, he would definitely feel it. But when he rides in the afternoon, he will have exhaled it again.

Mielke: So, will he be flying, or what?

Nybo: No, because there’s no effect from it. But if we tested him immediately after measuring this, it would be inhibiting.

Mielke: Would there be an effect if he did it day after day?

Nybo: If he only did this, with the small amount we are giving here [Netserk: 1 mL CO per kg body mass], my guess is that he would need to do it 5-6 times a day for three weeks to see an effect.

Mielke: But what if you increased the dose? That’s what you mentioned earlier.

Nybo: Yes, then maybe he could get away with doing it 4 times a day or 3 times a day. But you need to do it multiple times a day because the levels are only elevated for a short time before it gets washed out again. And especially if you are a trained cyclist, they breathe more, so they exhale it faster.

Mielke: And that’s what could be performance-enhancing if done systematically?

Nybo: Yes, that’s what some studies have shown.

If the goal is maximum performance and not merely getting a statistically significant result that can be published (with an experiment that passes the IRB/ethics committee), I don't see why such a precisely induced (and stronger) hypoxia wouldn't get greater effects than ordinary altitude.

 

[Sciatic]

Yes, but the point, as I understand it, is that high levels of carboxyhemoglobin can counteract these benefits, at least in the short term. So you'd first have to use it for an extended period, which comes with considerable health risks, and then stop using it; and even then, it's unclear whether there are any actual benefits compared to regular altitude training.

Cycling performance determinants improved more with CO inhalation at moderate altitude compared to sea-level training, whereas there were no differences in submaximal and maximal performance measures compared to moderate-altitude training alone.

https://pubmed.ncbi.nlm.nih.gov/39236115/

I’m not questioning your doubts about the effectiveness of CO2 shenanigans. I only questioned your statement that a higher hematocrit doesnt help if produced that way. A higher hematocrit deliveries more oxygen than a lower one until someone gets above 60-70 % (when blood flow gets slowed).

 

[Netserk]

Also hilarious that he says that bike riders have higher blood values than XC skiers. Brian Holm has 12.6 g Hb per kg body mass, Vingegaard 18-19.

 

[kingjr]

I’m not questioning your doubts about the effectiveness of CO2 shenanigans. I only questioned your statement that a higher hematocrit doesnt help if produced that way. A higher hematocrit deliveries more oxygen than a lower one until someone gets above 60-70 % (when blood flow gets slowed).

I'm not sure I fully understand this myself, but it seems to be like this: Your point is true in general, but it does not account for the effects of COHb. A higher hematocrit that includes a significant fraction of non-functional hemoglobin does not guarantee improved oxygen delivery.

The point of the CO rebreathing appears to be long-term adaptation, where the body clears COHb but retains the additional RBCs.

 

[Netserk]

I'm not sure I fully understand this myself, but it seems to be like this: Your point is true in general, but it does not account for the effects of COHb. A higher hematocrit that includes a significant fraction of non-functional hemoglobin does not guarantee improved oxygen delivery.

The point of the CO rebreathing appears to be long-term adaptation, where the body clears COHb but retains the additional RBCs.

I'd think the best aspect is drug free reticulocytes, which should make it much easier to mask blood bags.

 

[kingjr]

I'd think the best aspect is drug free reticulocytes, which should make it much easier to mask blood bags.

Bringing us neatly back to Fester's comment yesterday which kicked off this discussion.

 

[zlev11]

I'd think the best aspect is drug free reticulocytes, which should make it much easier to mask blood bags.

yeah this makes the most sense to me. you could drop a mega blood bag and use the CO to get your reticulocytes to mimic what they would be if you never infused more blood (they used to microdose EPO to do this). it still doesn't really explain why someone like Pogacar can be at such a huge level all season long though, if he's blood doping then he should have more peaks and troughs throughout the year. i guess it's possible he can do most of the year just with his talent and lesser octane doping and then when he wants to smash a Pantani record by 4 minutes, it's BB and CO time.

 

[Netserk]

yeah this makes the most sense to me. you could drop a mega blood bag and use the CO to get your reticulocytes to mimic what they would be if you never infused more blood (they used to microdose EPO to do this). it still doesn't really explain why someone like Pogacar can be at such a huge level all season long though, if he's blood doping then he should have more peaks and troughs throughout the year. i guess it's possible he can do most of the year just with his talent and lesser octane doping and then when he wants to smash a Pantani record by 4 minutes, it's BB and CO time.

That shouldn't be a problem with frozen blood.

 

[Sciatic]

I'm not sure I fully understand this myself, but it seems to be like this: Your point is true in general, but it does not account for the effects of COHb. A higher hematocrit that includes a significant fraction of non-functional hemoglobin does not guarantee improved oxygen delivery.

The point of the CO rebreathing appears to be long-term adaptation, where the body clears COHb but retains the additional RBCs.

I’d be interested in the research showing how that effect on hemoglobin/hematocrit is substantiated. I understand quite well how eythropoiesis (generation of new blood cells) works, and how faulty RBCs (wrong shapes, sizes, color) effect blood transport. I have a bone marrow disorder and the only reason my hematocrit is above 28 is from weekly EPO injections (x14 months). I can see on the blood smear analysis from my monthly blood tests that some of my RBCs are faulty (mix of different sizes, misshapen). Regardless of poorly functioning machinery and to produce blood cells, one thing is constant: higher HCT/HGB = more oxygen delivery. Perhaps you’re saying that there is not as much of an oxygen boost with the CO2 stuff than there is from Altitude, EPO, blood bags? But I don’t think it’s possible to have an increased HCT that doesn’t supply more oxygen.

 

[Netserk]

I’d be interested in the research showing how that effect on hemoglobin/hematocrit is substantiated. I understand quite well how eythropoiesis (generation of new blood cells) works, and how faulty RBCs (wrong shapes, sizes, color) effect blood transport. I have a bone marrow disorder and the only reason my hematocrit is above 28 is from weekly EPO injections (x14 months). I can see on the blood smear analysis from my monthly blood tests that some of my RBCs are faulty (mix of different sizes, misshapen). Regardless of poorly functioning machinery and to produce blood cells, one thing is constant: higher HCT/HGB = more oxygen delivery. Perhaps you’re saying that there is not as much of an oxygen boost with the CO2 stuff than there is from Altitude, EPO, blood bags? But I don’t think it’s possible to have an increased HCT that doesn’t supply more oxygen.

The COHb cannot carry any oxygen, so if your concentration of that is 10% after rebreathing CO, your effective Hb mass is similarly lower, even if your HCT is unchanged (at first). But the CO will leave your system again, so it's only a temporary inhibitor.

 

[Red Rick]

I think it's weird to assume they stopped CO rebreathers just because they said they would.

To me it seems like a ban that has 0 teeth to it.

 

[Sciatic]

The COHb cannot carry any oxygen, so if your concentration of that is 10% after rebreathing CO, your effective Hb mass is similarly lower, even if your HCT is unchanged (at first). But the CO will leave your system again, so it's only a temporary inhibitor.

Got it.

 

[E_F_]

I think it's weird to assume they stopped CO rebreathers just because they said they would.

To me it seems like a ban that has 0 teeth to it.

Of course. Perhaps they're keeping a low profile just for the time being? I would think they were more brazen with it back when it was still legal.

 

[Netserk]

Of course. Perhaps they're keeping a low profile just for the time being? I would think they were more brazen with it back when it was still legal.

It was never legal if used to induce hypoxia.

 

[Red Rick]

It was never legal if used to induce hypoxia.

It's the stupidest thing about it. It clearly violates the oxygen vector manipulation rules of WADA, but they just lol admitted to it.

Seems to me it's mostly the blood passport that's completely busted at this point.

 

[Netserk]

It's the stupidest thing about it. It clearly violates the oxygen vector manipulation rules of WADA, but they just lol admitted to it.

Seems to me it's mostly the blood passport that's completely busted at this point.

I think the new regulations are good, even if they do little. If the police come knocking and a team has banned equipment, that should result in bans. Before, they could just say it was only for the legal measurements of total Hb.

 

[E_F_]

It was never legal if used to induce hypoxia.

Ah, sorry. But still easier to explain why you're huffing CO back then.

 

[Roku]

Scaroni turning from a pre Vini Fantini Mauro Santambrogio kind of rider to a mix between Scarponi, Bartoli, Rebellin and Bettini (which would effectively be a Vini Fantini Mauro Santambrogio level) is the most unexpected story of the season

Wonder how much he will last.

 

[Mayomaniac]

Scaroni turning from a pre Vini Fantini Mauro Santambrogio kind of rider to a mix between Scarponi, Bartoli, Rebellin and Bettini (which would effectively be a Vini Fantini Mauro Santambrogio level) is the most unexpected story of the season

Wonder how much he will last.

He was already really good at the start of last season, 4th on Malhao behind Dani Martinez, Evenepoel and Pidcock + 4th in Laigueglia. He was already really good on shorter climbs and ran out of steam quick after a hot season start.
If he can keep this one up longer and also perform on longer climbs, then you have a point, but at this stage it's not that extreme to me.

 

[Samu Cuenca]

He was already really good at the start of last season, 4th on Malhao behind Dani Martinez, Evenepoel and Pidcock + 4th in Laigueglia. He was already really good on shorter climbs and ran out of steam quick after a hot season start.
If he can keep this one up longer and also perform on longer climbs, then you have a point, but at this stage it's not that extreme to me.

Has he lost weight or what is his explanation?

He is obviously older and more established, but his improvement is still giving me some 2022 to '23 Ben Healy vibes. We'll see if he too can continue to perform once we hit the bigger races.

That said, most of the team performing well/better than expected at this stage, so it would come as no surprise if their results took a dive soon.

 

[Netserk]

He was already really good at the start of last season, 4th on Malhao behind Dani Martinez, Evenepoel and Pidcock + 4th in Laigueglia. He was already really good on shorter climbs and ran out of steam quick after a hot season start.
If he can keep this one up longer and also perform on longer climbs, then you have a point, but at this stage it's not that extreme to me.

Also really good in PN, but he rode for KoM (he was 4th on Peille, faster than Skjelmose and McNulty).