Stephen Seiler

Every well-read exercise physiologist knows that cross-country skiers are at the top of the table for maximum oxygen consumption. Even back in the 1970s, Scandinavian physiologists reported values of over 90 ml/min/kg. But with mere meters deciding world-cup placings in events over tens of kilometers, the drive for ever higher oxidative capacity is relentless. Has it now become deadly?

Altitude training, despite all the controversies regarding its effectiveness, has been used for decades to increase oxidative capacity. Recently the approach has become more sophisticated. A single three-week altitude camp in the early Fall has been replaced by repeated excursions to altitude lasting 7-21 days interspersed throughout the world-cup schedule. It gets more complicated. The hypoxic conditions generated by training at altitude stimulates erythropoetin production and an increase in hemoglobin concentration. But, if you train very high, the absolute work intensity is compromised and the muscular system may become relatively detrained. So, now the athletes "live high and train low", or at least come down the mountain enough during a camp to do high-intensity training bouts under near normal oxygen partial pressures. But this traveling from country to country in search of early season snow and thin air, and then up and down the mountain regularly when you get there, is both expensive and stressful. So, "altitude houses" have emerged to bring the mountains to the athletes. Then this year, in Norway, the altitude house was given a set of wheels. Two camping trailers were custom outfitted with oxygen and CO2 scrubbing systems, plus humidity and temperature controls to "put the Alps inside a Winnebago". Inside, "chosen" athletes can eat and sleep at an effective altitude of 3,500 meters. Do everything right, and you can end up in peak condition and with a "supernormal" 16.5 to, in rare cases, 17+ grams of oxygen carrying hemoglobin in every 100 milliliters of blood (15.5 to 16 g/dl for the females). The result is perhaps 2-3 ml/min/kg higher VO2 max in the positive responders, a slightly higher pH buffering capacity, and crucial 10s of seconds in a 10 k race. There are some skiers who are looking for even more.

Beginning at the world championships in 1989 and continuing through to the "trial worlds" in Trondheim, Norway in February 1996, the International Ski Federation (FIS) began randomly drawing blood samples from male and female skiers to monitor hemoglobin levels. In 89, the average values were actually just under normal population levels (15 g/dl). By 1996 they were far over normal levels. The athletes could have pointed defensively to better use of altitude training except for a more alarming finding. Some individual measurements revealed hemoglobin concentrations of over 19 g/dl, even in females! A few skiers were walking around with a combination of extreme training induced bradycardia and ultra-high hematocrit that was unnatural by any definition and deemed "deadly" due to the resulting risk of embolism. This same pattern has been implicated in the deaths of dozens of professional cyclists over the last decade. Altitude training is not potent enough to induce these changes. The problem is DNA-recombinant erythropoetin (RhEPO). The athletes are clever, but they didn't discover this on their own. They got help from the field of medicine and from "medical support" who choose to give athletes drugs.

Recombinant erythropoetin became available in 1985, and is used to treat patients with impaired EPO production. Benefactors of this breakthrough included patients with renal disease who suffer from EPO deficient anemia. Shortly after, it was demonstrated the EPO administration to healthy subjects for 6-8 weeks resulted in increased VO2 max and performance time to exhaustion. RhEPO was immediately recognized as a threat to fair competition in endurance sports. It was quickly classified as a doping substance by the FIS in 1988 and by the IOC in 1990. This ban was made despite the fact that no methods for precise detection of RhEPO in blood or urine had been developed. With no way to enforce the ban, all FIS could do was measure the drug's impact.

In October of this year, the conservative FIS made a very aggressive decision. Beginning during the 96/97 Word Cup season male and female skiers will be subject to blood testing. Based on medical data and the six years of testing, it was determined that hemoglobin levels of 16.5 g/dl for women and 18.5 g/dl were upper-limit legal levels. Was this decision premature? Initially, athletes testing over the legal limit before the race would be disqualified from race participation. Then FIS changed their mind and decided to test after races and disqualify the results of positive tested skiers. Other punitive actions are unknown. FIS has presumably acted in the interest of safety and fair-play. But are the new rules doomed to result in further controversy? I think so, and here is why.

First, altitude training can in rare cases, push male hemoglobin levels into the low 17s, according to unpublished measurements from elite athletes trained at 2000 meters and higher. Some females have been measured at 15.8 to 16 g/dl after altitude exposure. If FIS tests immediately after a race, could the dehydration induced plasma volume reduction result in sufficient transient hemoconcentration to push a "clean" altitude trained skier over the arbitrary limit of 18.5, or 16.5? It seems possible. The mere fact that they want to test after races suggests they haven't thought about this issue. Second, methods for detection of RhEPO have been recently developed (Wide et al., 1995) that could prove more definitive. These investigators suggest that since EPO treatment requires 6-8 weeks for effectiveness, but becomes undetectable after a week, out-of competition doping controls administered weeks before a competition might prove more effective and more decisive. Finally, given that altitude training in all its artificial varieties is not considered "doping", safety must be the overriding issue driving the FIS rules. The International Skiing Federation does not want to share the black cloud of sudden deaths attributed to RhEPO use that hangs over professional cycling. Yet if safety is the key, then why is it "unsafe" for a women to have hemoglobin levels of 16.5, a value commonly observed in altitude trained men, but "safe" for a male to come in at 18.4?

Progress at Any Cost?

The search for speed continues. The connection between XC skiing and sport science has been strong for years, beginning with the physiological studies of Åstrand and others, and progressing to the materials science and biomechanics that have helped revolutionize XC skiing in the last decade. We have much in common and we have learned from each other. As in the past, both will depend on creativity, innovation, and cooperation to continue moving forward. Sadly, both the sport of XC skiing and the science of "sport" are threatened and damaged by the cancer of drug use. In the end, we both lose when sport becomes a hazard to an athlete's health instead of a extension of it. Sports scientists are contributing to both the cancer and the cure. Which side are you playing on?


Late November marked the beginning of the World Cup Cross country ski season. With it began the blood testing controversy. The source of the controversy has not been positive test results, but the fact that there have been positively no tests. Athletes stood in line to be tested at early events, only to be turned away. Scandinavian papers have been awash with commentary and comment from athletes who have questioned the motives of International skiing authorities. Some top skiers subjected themselves to private tests before and after races, once they became aware of the dehydration issue. We would like to believe the delay was at least partly a result of telephone calls placed to FIS, explaining the concerns outlined above. New test procedures, based on same-day, pre-race testing, were finally implemented on January 18-19 at Lahti, Finland. Athletes with morning, seated hemoglobin levels above the limit values are allowed a retest 30 minutes later. Two positive tests result in exclusion from the competition. At Lahti, none of the athletes tested positive. The testing was not without suspense, however. One high ranking athlete was in the testing room for an inordinately long period, with team coach and doctors visably nervous as they waited outside the door. The athlete "passed", then sustained a freak injury while warming up, and was immediately placed on a 20 day "disabled list" by her coaches.


Wide L., Bengtsson C., Berglund B., and Ekblom B. (1995). Detection in blood and urine of recombinant erythropoetin administered to healthy men. Medicine and Science in Sports and Exercise, 27, 1569-1576.

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