Doping in XC skiing

[Goldberger]

Can somebody answer a simple question? We know some of Lance's Hemoglobin values from 2009 and 2010 right? How are they compared to the Norwegian skiers from the 90's?

 

[python]

#python: I notice that you don’t seem to take kindly to newcomers. I still hope that you may find these figures of some interest. They indicate the number of currently active male XC athletes with a valid FIS license, nations selected by me.

AUT: 83
GER: 194
SWE: 495
FIN: 513
RUS: 724
NOR: ~1.700

Of course, this is just the top of the iceberg, as many racers do not care to apply for a FIS license (young racers, racers only interested in local races etc.). In Norway the total number of licensed racers in the 2011/12 season was 8.684, up from 7.855 the previous season. I do not have corresponding figures for other nations.

http://www.fis-ski.com/uk/competito...NOR&status=O&fiscode=&Search=Search&limit=100
http://www.skiforbundet.no/langrenn...s Fagmøte juni 2012/Skilisenser 2011-2012.pdf

i don't have a problem with new posters. i only notice that some appearances and and quick disappearances COINCIDE with the appearance and a disappearance of certain controversial issues.

that said, your first post was a constructive contribution as it advanced the discussion about a 'natural selection' towards a more definitive answer to the question i asked...

BUT, as you noted, it is an incomplete one to even start entertaining (the best would be to formally study) a very complex issue that norway somehow breeds superior athletes capable of beating blood doped elite from the rest of the world.

to add a counterpoint to your numbers, i have done a limited search on my own and found that one major nation with proven dirty reputation and usually beaten by normay (russia) can boast a considerably larger number of nationally licensed/registered xc skiers - between 9000 - 10,000 (i could not find the exact number). the number of unregistered local racers is probably even larger than in norway,

so, it does not appear that norway holds the lead in grass roots racing but, i will concur, normay does lead in quality...but that's a long way from concluding that norway has a an exclusive key to breeding super racers.

 

[Discgear]

so, it does not appear that norway holds the lead in grass roots racing but, i will concur, normay does lead in quality...but that's a long way from concluding that norway has a an exclusive key to breeding super racers.

Without doubt they are spending the most money, have the best support and are in front when it comes to training and equipment. Another important thing it's that almost the entire population in Norway is close to skiing opportunities due to the mountains and the climate. That's a big difference when you compare to Sweden. However, my impression is that Sweden has the lead in the science surrounding cross-country skiing.

My biggest issue is that all the years Norway has been very keen on telling everyone how high standards Norway has in sport ethics and they do have a very powerful say in FIS and WADA.

With everything that has rolled up since Lahti 2001 it amazes me that so few questions have been asked about the 90s. And the few attempts that have been made have been silenced by threats and in an aggregated tone from the Norwegians. It raises a lot of questions.

 

[workingclasshero]

Without doubt they are spending the most money, have the best support and are in front when it comes to training and equipment. Another important thing it's that almost the entire population in Norway is close to skiing opportunities due to the mountains and the climate. That's a big difference when you compare to Sweden.

what a load of bollox that bolded part is. Complete and utter nonsense, there are no secrets to training that only the Norwegians hold. That is such an odd, typical norwegian thing to say.

The training performed by the ruskies impressed Sundby when he had one or two of them visiting (later popped for PEDs though!)

Another important thing it's that almost the entire population in Norway is close to skiing opportunities due to the mountains and the climate. That's a big difference when you compare to Sweden.

what? the whole western part of the country is basically non-skiing (yes yes, Sjur Rothe).

In fact most of the best skiers both today and historically come from a tiny population in the middle part of the country.

(of course there are exceptions)

 

[Cobblestones]

Northug faded pretty badly, which I guess is a good sign. On the other hand, it also looked like the Norwegians didn't do a good job preparing their skis. No magic potion there.

 

[workingclasshero]

In this article from New York Times there are some revealing facts, but you can’t find any information about this in Norwegian newspapers online http://www.nytimes.com/1994/02/28/sports/winter-olympics-smirnov-s-long-race-and-wait-are-over.html

not a single revealing or interesting fact here I'm afraid, it is well known in Norway that smirnov, daehlie and ulvang used to be very good friends, if you have access to TV 2 online you can watch reruns of the hiking programme they used to do together.

And di Centa from this article in New York Times http://www.nytimes.com/1994/02/14/sports/winter-olympics-di-centa-of-italy-shouts-volare-to-freestyle-gold.html:



Today it seems to be a widespread consensus that di Centa, a Conconi protégé and Smirnov was doped. What about the two Norwegian friends which were even more successful in the forests? How come no Norwegian journalists hasn’t dug into those connections?

but this one's funny, although it doesn't prove Ulvang doped, at least he banged manuela di centa, quality!

ps. interesting that Ulvang didn't have a successful olympics in '94, anyone have ideas why? He did very well in the '92 olympics, perhaps he wasn't all that talented but an early EPO user in the sport of xc skiing and by '94 the rest had caught up with him?

 

[dukoff]

Your assertion is that "natural selection" gives Norway the edge to win. If today's field is clean, why aren't Norwegians now beating everyone else by that 10% margin?

It's a good point to make. Though I think 10% is not realistic for a top level athlete, more like 5%+. And you can shave off a couple % by proper altitude training.

First of all, why exactly should today's field be clean, and how clean can we assume it to be?

We are beating the field quite hard on the womens side. The effect is noticable there. Yet some say that's special because it's such a thin field. Well that is exactly the point, that xc in general is a very thin field, not just the women. But while the men's field were still rather thin in the 90s, it's not so much today. And on the men's side since Dæhlie and Alsgaard Norway simply haven't had that type of talent, and the competition has become much better. In the 90s there really wasn't much quality stock to compete with. Gunde Svan, Wassberg and Mogren was out of the picture. The fall of ussr also put a systemic brake on the steady supply of performers they had through the 70s/80s.

And which nation would be supposed to dominate, if any? There were only Norway, Sweden, Finland and USSR with any historic precedence.

Compared to the field, the Norwegians were truely unique talents, and in a bit of a vacuum. Alsgaard recently finished 3rd in Norwegian national championship races two years in a row at the age ~40. This caused a great deal of embarressment for the Norwegian coaches.

Now just note that I haven't said that selection counts for the whole difference. What I've said is that I consider it the major factor. Without it, other advantages would not be sufficient to win. But I have isolated the arguments on this one issue, to make it even possible to reach some understanding.

To give my view on quantifying the numbers, I would suggest:
EPO advantage: +6%
Altitude training: 2%
Ski-grinding: 1.5% (on some snow conditions) up to 1992, then tapering off.
Technique/Efficiency: unknown
Waxing: +/- 0-1.5%.

We can discuss each of these individually. But to answer your question, the magnitude of doping-gain I consider had to be overcome by means of physical and talent/efficiency -advantage in the 90s lay in the range of 2~3%.

I also would like to say that I think the view that EPO made a quantum-leap on performance is very inaccurate. Before EPO you still had extensive use of other blood doping and peds. While EPO had a substantial impact due to it's ease of use, that is something which make a serious impact in cycling, with continuous racing over several weeks and locations. But it's not in itself any major leap in performance gain for single races like you have in xc.

 

[Tubeless]

It's a good point to make. Though I think 10% is not realistic for a top level athlete, more like 5%+. And you can shave off a couple % by proper altitude training.

First of all, why exactly should today's field be clean, and how clean can we assume it to be?

We are beating the field quite hard on the womens side. The effect is noticable there. Yet some say that's special because it's such a thin field. Well that is exactly the point, that xc in general is a very thin field, not just the women. But while the men's field were still rather thin in the 90s, it's not so much today. And on the men's side since Dæhlie and Alsgaard Norway simply haven't had that type of talent, and the competition has become much better. In the 90s there really wasn't much quality stock to compete with. Gunde Svan, Wassberg and Mogren was out of the picture. The fall of ussr also put a systemic brake on the steady supply of performers they had through the 70s/80s.

And which nation would be supposed to dominate, if any? There were only Norway, Sweden, Finland and USSR with any historic precedence.

Compared to the field, the Norwegians were truely unique talents, and in a bit of a vacuum. Alsgaard recently finished 3rd in Norwegian national championship races two years in a row at the age ~40. This caused a great deal of embarressment for the Norwegian coaches.

Now just note that I haven't said that selection counts for the whole difference. What I've said is that I consider it the major factor. Without it, other advantages would not be sufficient to win. But I have isolated the arguments on this one issue, to make it even possible to reach some understanding.

To give my view on quantifying the numbers, I would suggest:
EPO advantage: +6%
Altitude training: 2%
Ski-grinding: 1.5% (on some snow conditions) up to 1992, then tapering off.
Technique/Efficiency: unknown
Waxing: +/- 0-1.5%.

We can discuss each of these individually. But to answer your question, the magnitude of doping-gain I consider had to be overcome by means of physical and talent/efficiency -advantage in the 90s lay in the range of 2~3%.

I also would like to say that I think the view that EPO made a quantum-leap on performance is very inaccurate. Before EPO you still had extensive use of other blood doping and peds. While EPO had a substantial impact due to it's ease of use, that is something which make a serious impact in cycling, with continuous racing over several weeks and locations. But it's not in itself any major leap in performance gain for single races like you have in xc.

Cross-country skiing is one of only few sports where the races last 15+ minutes and requires the use of all limbs. This is the often-cited reason why high VO2Max is the most important characteristic for top performance in ski racing. What's the most effective way to boost VO2Max? Blood doping.

A cyclist with an average VO2Max can win long bike races, even classics. A skier with an average VO2Max has no chance.

Conclusion? Arguably, EPO had much more of an effect in cross-country skiing than for cycling. The devastating impact of EPO in cycling is well-documented. We're just learning that it was the same (or worse) in elite skiing.

Chapter 6 from Tyler Hamilton's book gives a specific example of what a rise from 14.1 to 16.4 g/dl in Hb can do for performance - 9.7% improvement in an uphilll time trial at 2 months apart. Smirnov's Hb of 19.7 is yet another level up from that. What basis do you have to state that EPO would give just a 2-3% boost?

 

[Trond Vidar]

Ski-grinding: 1.5% (on some snow conditions) up to 1992, then tapering off.
Waxing: +/- 0-1.5%.

Choosing the right grind is also crucial. I was out skiing yesterday with a friend in Holmenkollen. I was skating, with a fairly fine structure - but with Gallium on top. The stuff that was made famous in Holmenkollen last year. The snow was changed, a little coarse and +1 degrees. Fantastic Gallium-weather, but not great structure for the snow. The skis were handpicked by Olav Stuveseth (pretty much the guy who revolutionised grinding in xc skiing in the early nineties)

My friend was skiing classical, hadn't prepped his skis for like two years. Structure for this kind of snow. Great set of skis though. Universalklister handmashed on at the start.

His skis were faster than mine going downhill. He had klister, I had skating skis.

Now, the point is simply this: Although skiing is physically demanding - there are still so many factors that adds minutes to your race time. Wax, grind, stiffness of the ski, the compactness of the snow, and not to forget how you keep you composure and technique when the going gets rough. You cannot look at any single race and make conclusions.

Here's is the workout by the way, Holmenkollen rules
http://app.strava.com/activities/43169276

I am loving the discussion in this thread. So many good thoughts and well laid out arguments.

 

[dukoff]

Chapter 6 from Tyler Hamilton's book gives a specific example of what a rise from 14.1 to 16.4 g/dl in Hb can do for performance - 9.7% improvement in an uphilll time trial at 2 months apart. Smirnov's Hb of 19.7 is yet another level up from that. What basis do you have to state that EPO would give just a 2-3% boost?

I just suggested an EPO gain of 6%, not 2-3%.

Your numbers for Tylar includes him going from 63.5kg to 60.8kg body weight. That can not be included for an analysis of the pure EPO effect. His watts output not considering that weight change is 5.7%, consistent with my estimate.

He went from a 5.9% body fat to 3.8%.

 

[workingclasshero]

And you can shave off a couple % by proper altitude training.

"proper altitude training"

stop saying this. EVERYONE trains at altitude.

Cologna LIVES at 1500m ffs!

Most of Kenya's population that runs are born and live their whole lives at 2000m+. Still people from the western world think they have a better altitude regime

Now, the point is simply this: Although skiing is physically demanding - there are still so many factors that adds minutes to your race time. Wax, grind, stiffness of the ski, the compactness of the snow, and not to forget how you keep you composure and technique when the going gets rough. You cannot look at any single race and make conclusions.

nice anecdote but I would expect pro's to be slightly better prepared. That said, I do think the skis are too important, at times xc skiing is more a vaxing contest than a physical one

 

[dukoff]

"proper altitude training"

stop saying this. EVERYONE trains at altitude.

Cologna LIVES at 1500m ffs!

Most of Kenya's population that runs are born and live their whole lives at 2000m+. Still people from the western world think they have a better altitude regime

If you use EPO, you have no reason to train at altitude. EPO can be considered to take you to a performance from base to +6%. Altitude training from base to +2%. Or more, depending on altitude which you compete. But you can't get +8% by doing EPO + altitude. Hence, the "legally unavailable" additional effect of EPO is only +4%, as some of the advantage is achievable by legal means. That was part of the point of my post further up.

Much of the physiological adaptions are the same. Just one is more effective, and illegal.

 

[workingclasshero]

If you use EPO, you have no reason to train at altitude. EPO can be considered to take you to a performance from base to +6%. Altitude training from base to +2%. But you can't get +8% by doing EPO + altitude. Hence, the "legally unavailable" additional effect of EPO is only +4%, as some of the advantage is achievable by legal means. That was part of the point of my post further up.

what?

that is, if you consider a higher HB the main or even only aim of altitude training.

which, funnily enough, is another typical norwegian trait.

Marius Bakken criticised this thinking.
He clearly didn't get through to yous.

 

[dukoff]

what?

that is, if you consider a higher HB the main or even only aim of altitude training.

which, funnily enough, is another typical norwegian trait.

Marius Bakken criticised this thinking.
He clearly didn't get through to yous.

You are free to document and quantify the differences you have in mind so we have a base for further discussion.

 

[Dear Wiggo]

If you use EPO, you have no reason to train at altitude. EPO can be considered to take you to a performance from base to +6%. Altitude training from base to +2%. Or more, depending on altitude which you compete. But you can't get +8% by doing EPO + altitude. Hence, the "legally unavailable" additional effect of EPO is only +4%, as some of the advantage is achievable by legal means. That was part of the point of my post further up.

Much of the physiological adaptions are the same. Just one is more effective, and illegal.

Is this for competing at altitude as well?

Coz if you're competing at sea level, ongoing EPO means your Hgb stays elevated. Altitude training effects diminish over time.

 

[workingclasshero]

You are free to document and quantify the differences you have in mind so we have a base for further discussion.

what, quantify as in taking numbers out of thin air like you did?

I'd rather quote Marius Bakken (google translated):

"Much of the recent research on altitude training focuses unfortunately almost entirely on getting higher "blood count". Some researchers say therefore relatively substantial that it should be at least 4 weeks in height to obtain a significant effect. This will provide twice the blood effect than 3 weeks.

The most important thing is that you get performance improvement of altitude training, not that you necessarily get higher blood levels.


Alongside an increase in blood levels will also altitude training result in changes at the gene level, pH, and significant changes in mitochondria. (Gore et.al 2006) This, and the sum of this, is what gives the effect on performance.

Hemoglobin decreases generally with around 0.5 g / dl in the week after returning to the lowlands. An athlete who has received a "blood effects" with hemoglobin increase from say 14 to 15 g / dl will be down to normal again after only two weeks in the lowlands by height stay.

When we know that the maximum performance effect in many of the athletes comes from the two weeks of the height and beyond, there is reason to question the importance of precisely this increase in blood levels."

altitude training for a higher HB only Only in Norway

 

[poupou]

I just suggested an EPO gain of 6%, not 2-3%.

Your numbers for Tylar includes him going from 63.5kg to 60.8kg body weight. That can not be included for an analysis of the pure EPO effect. His watts output not considering that weight change is 5.7%, consistent with my estimate.

He went from a 5.9% body fat to 3.8%.

Is it possible to train efficiently with a 3.8% body fat? Or that level of fat is the consequence of doping (can train harder and recover easily with PED)?

 

[Trond Vidar]

nice anecdote but I would expect pro's to be slightly better prepared. That said, I do think the skis are too important, at times xc skiing is more a vaxing contest than a physical one

Fully agree. Pro's are obviously way more prepared than any of us. But they make mistakes too. The Swedes clearly had worse skis than the Norwegians in Holmenkollen last year.

 

[Discgear]

not a single revealing or interesting fact here I'm afraid, it is well known in Norway that smirnov, daehlie and ulvang used to be very good friends, if you have access to TV 2 online you can watch reruns of the hiking programme they used to do together.

Well, you certainly missed (by purpose?) my point. Of course the friendship between Dählie, Ulvang and Smirnoff is wellknown to the Norwegian public. But I'm not sure that it's well known that the friendship started well before Lillehammer and certainly not that Manuela Di Centa was a part of this illistrious group. Besides that, I don't think this forum is read by Norwegians only and finally my point was: You might think there should have been at least some interest from investigating journalists to dig into this information after the doping scandal around Conconi rolled up.

A cyclist with an average VO2Max can win long bike races, even classics. A skier with an average VO2Max has no chance.

Indeed, one of the early anecdotes about the greatness of Dählie was that he held the world record of VO2Max 96 ml/kg/min. Later, after the widespread missuse of EPO came to public knowledge, we heard from the Norwegians that something was wrong with the test and that his VO2Max was significantly lower.

If you use EPO, you have no reason to train at altitude.

I don't agree. A good reason for High Altitude Training is to use it for explaining high blood values achieved by other means. And this argument - which were frequently used by the Norwegian leaders in the aftermath of the Swedish Documentary last week - was badly smashed by prof. Saltin when he stated that the high values achived by High Altitude will drop back to normal in 48 hours when you return to sea level.

 

[dukoff]

what, quantify as in taking numbers out of thin air like you did?

I'd rather quote Marius Bakken (google translated):

"Much of the recent research on altitude training focuses unfortunately almost entirely on getting higher "blood count". Some researchers say therefore relatively substantial that it should be at least 4 weeks in height to obtain a significant effect. This will provide twice the blood effect than 3 weeks.

The most important thing is that you get performance improvement of altitude training, not that you necessarily get higher blood levels.


Alongside an increase in blood levels will also altitude training result in changes at the gene level, pH, and significant changes in mitochondria. (Gore et.al 2006) This, and the sum of this, is what gives the effect on performance.

Hemoglobin decreases generally with around 0.5 g / dl in the week after returning to the lowlands. An athlete who has received a "blood effects" with hemoglobin increase from say 14 to 15 g / dl will be down to normal again after only two weeks in the lowlands by height stay.

When we know that the maximum performance effect in many of the athletes comes from the two weeks of the height and beyond, there is reason to question the importance of precisely this increase in blood levels."

altitude training for a higher HB only Only in Norway

This is well known. But all the effects are initiated by the training and living under a physiological condition of elevated blood parameters and the following natural elevated EPO levels. Individual EPO increase is a factor accurately indicating responders from non-responders.

There is nothing to suggest the effects of training under artificially boosted EPO will not include much of the same changes.

Further EPO levels measured with respect to altitude training shows a noticeable lasting increase in responders even after 14 days, when Hb levels have returned to normal levels.

I didn't suggest the main goal of altitude training is elevated Hb levels, that is your words. The goal is naturally elevated EPO levels.

 

[dukoff]

what, quantify as in taking numbers out of thin air like you did?

I'd rather quote Marius Bakken (google translated):

"Much of the recent research on altitude training focuses unfortunately almost entirely on getting higher "blood count". Some researchers say therefore relatively substantial that it should be at least 4 weeks in height to obtain a significant effect. This will provide twice the blood effect than 3 weeks.

The most important thing is that you get performance improvement of altitude training, not that you necessarily get higher blood levels.


Alongside an increase in blood levels will also altitude training result in changes at the gene level, pH, and significant changes in mitochondria. (Gore et.al 2006) This, and the sum of this, is what gives the effect on performance.

Hemoglobin decreases generally with around 0.5 g / dl in the week after returning to the lowlands. An athlete who has received a "blood effects" with hemoglobin increase from say 14 to 15 g / dl will be down to normal again after only two weeks in the lowlands by height stay.

When we know that the maximum performance effect in many of the athletes comes from the two weeks of the height and beyond, there is reason to question the importance of precisely this increase in blood levels."

altitude training for a higher HB only Only in Norway

This is well known. But all the effects are initiated by the training and living under a physiological condition of elevated blood parameters and the following natural elevated EPO levels. Individual EPO increase is a factor accurately indicating responders from non-responders.

There is nothing to suggest the effects of training under artificially boosted EPO will not include much of the same changes.

Responders are shown to train under EPO levels boosted to 130-160%.

 

[python]

It's a good point to make. Though I think 10% is not realistic for a top level athlete, more like 5%+. And you can shave off a couple % by proper altitude training.

I generally agree with this estimate (and with your interpretation of tyler‘s gains) , though, in the 90’s the epo advantage could probably be pushed another couple % up by those willing to take the extra health risk - as there was no epo test to fear. Still, your argument that natural selection trumps blood doping remains a convenient hypothesis. notwithstanding your other numbers below

To give my view on quantifying the numbers, I would suggest:
EPO advantage: +6%
Altitude training: 2%
Ski-grinding: 1.5% (on some snow conditions) up to 1992, then tapering off.
Technique/Efficiency: unknown
Waxing: +/- 0-1.5%

.
Taken at face value, these numbers (except the last one - waxing) are not unrealistic even plausable (based on personal experience and some reading) but there are 3 problems with your numbers. Problem 1 - selection of proper ski STIFFNESS is lacking. Wrong stiffness accounts for more than a perfect wax. Problem 2 - they never are fixed values but ranges, particularly over the developments in the 90s. Speaking of waxing (also see trond‘s and wch posts), even at the elite level, the difference may exceed 5% in extreme cases as was illustrated by northug vs. legkov times in the individual 15 k skate in val di fiemme. A perfectly gliding northug was 7% faster than legkov who (as we now know for a fact) was skating on bare plastic bases starting at km 2. If northug was fitter that day than anyone by 1-2% (which he probably was), the rest of the difference must have been in the skis. Problem 3 is that the factors above are RANDOM variables. the elementary common sense and statistics tell us that they can NOT always line up in the direction beneficial to norway only , much less for over 10 years ! There are days when even norwegian servicemen make mistakes. besides, even if we assume that Norway somehow held a stone-grinding + waxing secret for a while, it can not be permanent in the era of hyper communication/mobile professional/cross-hiring. thinking otherwise is fitting facts to a forgone conclusion.

all these considerations make your simple natural selection theory.. well, a convenient unproven theory. all that, while new questions about the norwegian 90's are either shoved aside, ignored or met with threat of court action.

 

[Trond Vidar]

Indeed, one of the early anecdotes about the greatness of Dählie was that he held the world record of VO2Max 96 ml/kg/min. Later, after the widespread missuse of EPO came to public knowledge, we heard from the Norwegians that something was wrong with the test and that his VO2Max was significantly lower.

A good read. Long lost, but the webarchive still has it.

http://web.archive.org/web/19990209200527/http://www.krs.hia.no/~stephens/bjorn.htm

 

[Discgear]

A good read. Long lost, but the webarchive still has it.

http://web.archive.org/web/19990209200527/http://www.krs.hia.no/~stephens/bjorn.htm

Indeed a good read, thanks! Back in the days, I really enjoyed reading about the great northern ski heroes. After Lahti, not so much anymore, since you really don't know what to think about outstanding achievements in endurance sports. Dählie was never my favorit, a little bit to narcissistic. Also his skiing techniques wasn't at all as impressive as Myllylä, Mogren or Alsgaard.
Myllylä was a real hero, almost in comparison with Wassberg. A silent, grumpy, tenacious northern man that always went his own way. Especially remember pictures from Myllyläs summer training with weights hanging around his chest, running with mud up to his belly button in swamps clouded by mosquitos.
That Myllyllä was doped, killed all illusions.

By the way, the Norwegians just announced they are not going to publish the blood values as the Swedes did last week.
Strange since Erik Roste - the day after the Swedish team went public and published highs and lows from the last three years for the swedish elite - announced that the Norwegian team would soon follow.

And just in this moment the Swedish Ski Federation announced that they are collecting all the values from the 90s to be released for the Swedish team.

 

[Mr. Brooks]

I find this discussion very interesting, and even if I am a new poster I have been following this thread (and quite a few others, bike related) for a long time.

I notice that some tend to question the impact of ski grinding and waxing techniques. While most nations today share more or less the same knowledge (generally speaking, there are still noteable exceptions), this was certainly not the case during a number of years in the nineties. The effect can be easily observed by the bare eye, by watching, say, how Sture Sivertsen glides away from the front of the field during the 1997 Trondheim WSC relay (ref. Youtube).

The glide differences have been studied more scientifically as well. One publicly available study is Street and Gregory’s article “Relationship Between Glide Speed and Olympic Cross-Country Ski Performance”:
“The purpose of this study was to determine whether glide speed was related to Olympic race performance. Male competitors in the 50-km freestyle event were videotaped during the 1992 Winter Olympic Games. Glide speeds of the entire field were measured through a 20-m flat section at the bottom of a 150-m, 12" downhill. A significant correlation (r = -.73) was found between finish time and glide speed, showing that the more successful competitors tended to have faster glide speeds through this section of the course. A predictive model of glide speed suggested that the faster glide speeds were due primarily to differences in friction.”

The quote above may seem obvious. The figures are amazing, though. Dæhlie’s skis were close to 4 pct faster than 2nd place de Zolt’s and more than 10 pct faster than 4th place finisher Prokurorov’s.

1. Dæhlie, glide speed 16,4 m/s
2. de Zolt, glide speed 15,8 m/s (-3,7%)
3. Vanzetta, glide speed 15,1 m/s (-7,9%)
4. Prokurorov, glide speed14,7 m/s (-10,4%)

1. Dæhlie, finish time 2.03.41,5
2. de Zolt, finish time 2.04.39,1 (+0,8%)
3. Vanzetta, finish time 2.06.42,1 (+2,4%)
4. Prokurorov, finish time 2.07.06,1 (+2,8%)

The above does not prove anything regarding who was or who wasn’t doping in the nineties. Whatever fast skis do, they do not produce more red blood cells. But as equipment is so vital in skiing, having consistently much better skis than your competitors will take a nice chunk out of the advantages others might have. Who knows, it might even be possible to win clean.