The Froome Files, test data only thread

[Le breton]

Re: Re:

One interesting bit from the paper which I find EXTREMELY surprising is that Froome performed better in HH (hot, humid) conditions than in normal conditions. I'm waiting for a reasonable explanation as this is so counterintuitive if you consider how far down marathon performances are in HH conditions compared to cool/cold conditions. His fan wind speed was marathon's speed ~20 km/h.

As long as the brain/core does not get too hot, an increase in ambient temperature should help shift the Hb-O2 curve to the right and increase the delivery of oxygen to working muscles, thus increasing available aerobic power.

In fact, I looked again at fig.1 and there is really no difference in efficiency between HH and ambient where it really matters, at the higher power values.
Furthermore, the tests were quite short and finished before the core temperature could rise significantly, i.e. reach values such that it would be surprising not to see a drop in efficiency just from the fact that too much of the blood is diverted to the skin for cooling.

 

[Merckx index]

Re: Re:

it is well-established from published studies of autologous transfusions that the relative increase in VO2max is generally half the relative increase in hematocrit. It is also well-established based on other studies (including animal work by, e.g., George Brooks) that relative changes in exercise performance will tend to be somewhat less than the relative increase in VO2max. It is therefore fairly easy to put reasonable bounds on the potential effects of, e.g., EPO on performance.

This is a little bit of a simplification, for several reasons:

1) While the V02max may increase about half as much as the HT on average among a group of subjects, there is considerable individual variation in these studies—all the way up to equal if not greater increases in V02max--and perhaps even variation from time to time for one individual. In Cycle of Lies, JV is reported saying he (sometimes) experienced a 4-6% increase in power (which is another step or steps further removed from V02max) from about an 8% increase in HT.
2) The situation is complicated by the fact that increasing HT can reduce cardiac output, so while there is more oxygen-carrying capacity in the blood, there may be less blood delivered to the muscles per unit of time. A relationship like this is very likely different for different individuals, and would be expected to be especially sensitive to natural or baseline HT.
3) Drawing conclusions about EPO from transfusions ignores the fact that in addition to its stimulation of red blood cell synthesis, EPO is thought to have growth-promoting effects in other tissues, including angiogenesis or vascularization. This could further enhance V02max.
4) Regarding the relationship between V02max and power, some studies show a roughly parallel increase. In fact, this is what one would expect, since power is calculated from V02max, GE and threshold. If the increase in power is less than the increase in V02max, this seems to indicate that the HT increase reduced efficiency and/or threshold. This is possible, but I’m not aware of studies exploring this.
5) In the real world of doping, riders are likely to supplement EPO or transfusion with other substances. We have very little idea of how these additional substances may affect the VO2max and power relationships.
6) There was that study, made much of by Ross Tucker, reporting that EPO increased submaximal performance far more than its effect on V02max, with time to exhaustion increased more than 50%. Interestingly, it seems that George Brooks found a similar effect in lab rats.

The bottom line, for me, is that when we talk about the effects of drugs on performance, it’s very difficult to draw a line beyond which enhancement is not possible (this should be evident to anyone who argues against drawing a line on natural power). The same logic that demands an extremely high bar to conclude doping also implies that some individuals may benefit far more from PES than the average subject. While we wouldn’t make rigorous conclusions based on one outlier in a study, assuming that outlier is real, we have to take that level of enhancement seriously when considering doping.

 

[Alex Simmons/RST]

Re: Re:

6) There was that study, made much of by Ross Tucker, reporting that EPO increased submaximal performance far more than its effect on V02max, with time to exhaustion increased more than 50%. Interestingly, it seems that George Brooks found a similar effect in lab rats.

Just one bit that caught my eye. Need to be careful when equating changes in TTE with changes in power or VO2max. TTE significantly amplifies changes in fitness due to the flatness of the mean maximal power-duration curve at longer (sub-maximal) durations.

 

[Merckx index]

Re: Re:

Just one bit that caught my eye. Need to be careful when equating changes in TTE with changes in power or VO2max. TTE significantly amplifies changes in fitness due to the flatness of the mean maximal power-duration curve at longer (sub-maximal) durations.

I wasn't equating change in time to exhaustion with change in maximal or even sustained power. I was responding, again, to AC's claim that we have a handle on how much EPO improves performance. Performance isn't all about maximal or threshold power. An increase in time sustainable at some lower power can also have a major effect on performance in a bike race.

 

[acoggan]

Re: Re:

Need to be careful when equating changes in TTE with changes in power or VO2max. TTE significantly amplifies changes in fitness due to the flatness of the mean maximal power-duration curve at longer (sub-maximal) durations.

Bingo.

 

[acoggan]

Re: Re:

Just one bit that caught my eye. Need to be careful when equating changes in TTE with changes in power or VO2max. TTE significantly amplifies changes in fitness due to the flatness of the mean maximal power-duration curve at longer (sub-maximal) durations.

I wasn't equating change in time to exhaustion with change in maximal or even sustained power. I was responding, again, to AC's claim that we have a handle on how much EPO improves performance. Performance isn't all about maximal or threshold power. An increase in time sustainable at some lower power can also have a major effect on performance in a bike race.

You just essentially contradicted yourself. That is, power at all durations beyond a handful of minutes is intimately linked to power at FTP.

 

[acoggan]

Re: Re:

4) Regarding the relationship between V02max and power, some studies show a roughly parallel increase. In fact, this is what one would expect, since power is calculated from V02max, GE and threshold. If the increase in power is less than the increase in V02max, this seems to indicate that the HT increase reduced efficiency and/or threshold. This is possible, but I’m not aware of studies exploring this.

You need to read a bit more, then. For example, Brooks' studies of iron deficiency address this question directly, whereas studies of aging address it indirectly. IOW, based on multiple lines of evidence it is apparent that increasing or decreasing VO2max by altering arterial O2 content results in smaller relative changes in endurance performance/threshold.

 

[Merckx index]

You just essentially contradicted yourself. That is, power at all durations beyond a handful of minutes is intimately linked to power at FTP.

The point is, time to exhaustion can increase far more following the same treatment than V02max. OK? Whether the rider is at threshold or below it, that increase can affect performance. Again, I was responding to your “less than half” claim.

You need to read a bit more, then. For example, Brooks' studies of iron deficiency address this question directly, whereas studies of aging address it indirectly. IOW, based on multiple lines of evidence it is apparent that increasing or decreasing VO2max by altering arterial O2 content results in smaller relative changes in endurance performance/threshold.

Are you serious? In one study, Brooks reported V02max increases of roughly 10-20%, while the increase in treadmill speeds at V02max was three or more times that, and changes in endurance were several hundred %.

 

[Alex Simmons/RST]

Re: Re:

Just one bit that caught my eye. Need to be careful when equating changes in TTE with changes in power or VO2max. TTE significantly amplifies changes in fitness due to the flatness of the mean maximal power-duration curve at longer (sub-maximal) durations.

I wasn't equating change in time to exhaustion with change in maximal or even sustained power.

The comment where you related Ross Tucker's reports on a study does exactly that.

I was responding, again, to AC's claim that we have a handle on how much EPO improves performance. Performance isn't all about maximal or threshold power. An increase in time sustainable at some lower power can also have a major effect on performance in a bike race.

There's is no doubt that increasing TTE is useful, I totally agree. However large changes in TTE at a given sub-max power is a natural consequence of one's threshold power improving no matter how an increase in threshold power is achieved (EPO or otherwise).

 

[Merckx index]

Re: Re:

There's is no doubt that increasing TTE is useful, I totally agree. However large changes in TTE at a given sub-max power is a natural consequence of one's threshold power improving no matter how an increase in threshold power is achieved (EPO or otherwise).

I understand. But again, AC's original comment implied that the increase in sustained power would be less than half of the increase in HT. He went straight from there to saying we had a good idea of the potential of EPO. Maybe he was just skipping over the rest, but the comment implied that a few % increase in sustained power was that potential, without noting that that relatively small increase can result in a huge increase in time to exhaustion. This might be obvious to him and you, I don't think it would be obvious to everyone in this thread. And in fact, the reason that EPO study was done was to find out just how much that increase was.

Moreover, given the huge increase in time to exhaustion, there is a very large uncertainty in how much may be possible by doping. Whereas one might argue that a certain % increase in HT will at most result in about the same increase in V02max, how much that increase in VO2 max in turn results in increased time to exhaustion is really unknown. One study in humans reported a little over 50%. The rat studies, where exercise was used to increase the V02max more than generally would be possible with EPO, reported as much as 800+%! There were also huge increases in speed (of the treadmill), so there is a multiplier effect in regard to power output. Presumably, increases that large from blood doping would not be possible, but just because one study found a little over 50% hardly sets the limit. It could be 100% or more, and again, the multiplier effect just increases the range of uncertainty. So--in addition to the other points I made--I don't see that we really have that good an idea of what the limits to power enhancement of blood doping are.

Finally, let's keep in mind the limitations of animal studies. It's often pointed out that studies of V02max, power, et al. in the usual human subjects may have limited relevance to elite riders. AC himself has taken this position, arguing, e.g., that efficiencies may improve with training in elite riders, and be beyond the range generally reported for non-elite subjects. How much more do such caveats apply when we aren't even studying humans, but lab animals? Do the trained animals "try" harder than the untrained ones, or is it all about physiology? Who knows?

I find this discussion with you and AC ironic, because both of you are among those who object to Tucker's line in the sand when it comes to the natural limits of human power. That point just above about efficiencies could be one justification for taking such a stand. But if those limits are fuzzy, the limits to doping enhancement are even fuzzier. At least we have some studies of elite riders to get an idea of what their theoretical maximum and sustained power could be. We have virtually no such studies with EPO and transfusions, certainly the obstacles to such studies are far greater than to studies of natural physiology.

 

[Alex Simmons/RST]

I don't see the relevance with concerns about setting an arbitrary sans-doping performance (W/kg) line in the sand. Let's leave that though, it's OT.

 

[Le breton]

If you look at the power/duration curve of your "average" cyclist (or at the average of such power/time curves) as represented on the 1st graph of this page
http://autobus.cyclingnews.com/fitness/?id=powerstern
(Hi Ric)
and plot it as semi-log you will find that above around 10 mn durations and beyond 60 mn you basically have a straight line.
Which means that on average you have a logarithmic relation between power and time to exhaustion (TTE).
This average is around a 7% drop in power for an increase in duration by a factor e = 2.718.
In other words, on average, a 50% increase in the TTE corresponds only to a 7% times ln1.5 = 7% times 0.4 i.e 2.8% increase in VO2.
Alternatively, a 2.8% increase in VO2, over a wide range of durations, for the vast mass of trained cyclists, corresponds to a 50% increase in TTE at the appropriate level.
Start shooting.
PS :
from Ric's observation at the bottom of the ref above
"Can race performance power be estimated?"

Although race performance can be down to mental strength as much as physical ability, a power/time curve exists such that the longer the event, the lower the power output. For endurance-based events, an estimate of the power output that can be achieved for a variety of distances is shown below.

Distance/Event Power range
(% of MAP)

3 km TT 89 - 91
4 km TT 88 - 91
16.1 km TT 75 - 81
40.2 km TT 72 - 77
80.5 km TT 64 - 72
161 km TT 60 - 68
You can obtain a value which (I have not verified my very old notes) is around the 7% I mentioned.

PS2
By the same token, an 800% increase in TTE corresponds to just 7% times ln 9 = 15% increase in VO2

 

[gillan1969]

we are essentially discussing the elephant performing better in Africa over Iceland, the rate of flow of water through an elephants trunk and uptake of water and discharge from said trunk without recognising that the subject never used to be an elephant.....

 

[acoggan]

Re: Re:

I find this discussion with you and AC ironic, because both of you are among those who object to Tucker's line in the sand when it comes to the natural limits of human power. That point just above about efficiencies could be one justification for taking such a stand. But if those limits are fuzzy, the limits to doping enhancement are even fuzzier.

I said "reasonable bounds" (and recognizing that anti-doping efforts are going to limit just how much someone can bump up their hematocrit). To wit:

A 10% (to pick a number) increase in hematocrit will result in, on average, about a 5% increase in VO2max. Sustainable power will increase in an absolute sense, but will decrease as a percentage of VO2max, since cardiovascular and muscular metabolic fitness are, to at least some extent, independent of each other. TTE will obviously increase by a much larger percentage, since as Alex pointed out the power-duration relationship is quite flat beyond the first few minutes of exercise. Nonetheless, that too can reasonably estimated, as Le breton's post demonstrates.

Bottom line: we don't need additional studies of blood doping or EPO to have a good handle on how much they can benefit endurance exercise performance.

 

[acoggan]

Re:

Start shooting.

My only criticism would be that increases in sustainable power due to blood doping or EPO will be roughly half (or less) than the increase in VO2max.

(Note that the same is true with respect to aging, i.e., decreases in sustainable power are generally less than the reduction in VO2max.)

 

[Le breton]

This might be a good time to look back on this other topic about Froome following the Ventoux 2013 controversy
viewtopic.php?p=1311180#p1311180
On page 6 I had posted the type of data (about Froome) passed on to Grappe by Brailsford.
The data on page 6 represent the power developed by Froome as a function of the duration of the corresponding effort.

 

[HP92]

I was reading this topic and created an account just to ask a quick thing to the experts. I would like someone to point out the flaw in my thinking.

For some people is quite normal that Froome has a very low HR. However, Froome produces, at least, the same amount of watts than his opponents. Given that his GE isn't "Not Normal" ("Vayerism" ;D ), I guess his muscles need the same amount of O2 as anyone else to produce that kind of power. As he needs the same O2 content, he needs the same cardiac output (admitting similar Hb, Htc and O2 saturation).

CO=HR x SV

So, if he needs the same CO at a lower HR, he needs a heart the size of a rhino! Take in account that I'm comparing Froome not to me (couch potato) but with some of the best athletes in the world.

Sorry for my poor English, and tell me please if I am wrong, and if so, where. Thank you!

 

[Irondan]

Re:

I was reading this topic and created an account just to ask a quick thing to the experts. I would like someone to point out the flaw in my thinking.

For some people is quite normal that Froome has a very low HR. However, Froome produces, at least, the same amount of watts than his opponents. Given that his GE isn't "Not Normal" ("Vayerism" ;D ), I guess his muscles need the same amount of O2 as anyone else to produce that kind of power. As he needs the same O2 content, he needs the same cardiac output (admitting similar Hb, Htc and O2 saturation).

CO=HR x SV

So, if he needs the same CO at a lower HR, he needs a heart the size of a rhino! Take in account that I'm comparing Froome not to me (couch potato) but with some of the best athletes in the world.

Sorry for my poor English, and tell me please if I am wrong, and if so, where. Thank you!

Welcome to the forum!

Great question which I will defer to the experts such as Merckx index, acoggin, Jereon swart, etc...

Cheers

 

[thehog]

Gesink, showing Swart/GSK how not to have heart rate strap slip off, double wrap.

Rookie error by the GSK crew on Froome :lol:

 

[acoggan]

Gesink, showing Swart/GSK how not to have heart rate strap slip off, double wrap.

Rookie error by the GSK crew on Froome :lol:

The "rookie error" is seeing a picture of someone with a standard 12 lead ECG set-up and assuming that the two black bands are heart rate monitor straps.

 

[LaFlorecita]

What do you reckon they're for?

 

[veganrob]

Would also seem to be a rookie error putting such straps on in such a way that they would slip down thereby not be able to record HR. And then not replacing straps in order to get said HR seems negligent and amateurish. Then with such an important test for the world to see and analyze might be construed as deceptive.

 

[sniper]

Re:

Would also seem to be a rookie error putting such straps on in such a way that they would slip down thereby not be able to record HR. And then not replacing straps in order to get said HR seems negligent and amateurish. Then with such an important test for the world to see and analyze might be construed as deceptive.

this.

but the negligence is hardly surprising seeing how they took that 2007 fax at face value, overlooking hard-to-overlook errors such as the mismatch of BMI and weight.

This job had amateurism written all over it.

 

[Alex Simmons/RST]

Why do you care about HR data? It's a couple of orders of magnitude less important than the stuff that was recorded and actually matters.

 

[thehog]

Re:

Why do you care about HR data? It's a couple of orders of magnitude less important than the stuff that was recorded and actually matters.

Are you that boring that you think eveything evolves around what you think?

We'all take hearrate whether you like it or not. We do not care what you think.