OBJECTIVE: There is widespread public concern about fairness in sports. Blood doping undermines fairness and places athletes' health at risk. The purpose of this study was to examine the prevalence of abnormal hematologic profiles in elite cross-country skiers, which may indicate a high probability of blood doping. SETTING AND PARTICIPANTS: Samples were obtained as part of routine International Ski Federation blood testing procedures from participants at the World Ski Championships. Sixty-eight percent of all skiers and 92% of those finishing in the top 10 places were tested. MAIN OUTCOME MEASURES: Using flow cytometry, we analyzed erythrocyte and reticulocyte indices. Reference values were from the 1989 Nordic Ski World Championships data set and the International Olympic Committee Erythropoietin 2000 project. RESULTS: Of the skiers tested and finishing within the top 50 places in the competitions, 17% had "highly abnormal" hematologic profiles, 19% had "abnormal" values, and 64% were normal. Fifty percent of medal winners and 33% of those finishing from 4th to 10th place had highly abnormal hematologic profiles. In contrast, only 3% of skiers finishing from 41st to 50th place had highly abnormal values. CONCLUSIONS: These data suggest that blood doping is both prevalent and effective in cross-country ski racing, and current testing programs for blood doping are ineffective. It is unlikely that blood doping is less common in other endurance sports. Ramifications of doping affect not only elite athletes who may feel compelled to risk their health but also the general population, particularly young people.
We studied 12 highly trained athletes, 6 male ice-hockey players and 6 cross-country skiers (2 females, 4 males). All of them participated in a maximal electrically braked bicycle ergometer test in a hypobaric chamber at the simulated altitude of 3000m (520 mmHg) and in normobaric conditions two days apart in random order. The maximal oxygen uptake was 57.4 +/- 7.1 (SD) ml/kg/min in normobaria (VO2maxnorm) and 46.6 +/- 4.9 (SD) ml/kg/min in hypobaric hypoxia (VO2maxhyp). The decrease in maximal oxygen uptake (delta VO2max) at the simulated altitude of 3000m correlated significantly (p
This investigation was designed to (a) develop an individualized mechanical model for measuring aerodynamic drag (F(d) ) while ski racing through multiple gates, (b) estimate energy dissipation (E(d) ) caused by F(d) and compare this to the total energy loss (E(t) ), and (c) investigate the relative contribution of E(d) /E(t) to performance during giant slalom skiing (GS). Nine elite skiers were monitored in different positions and with different wind velocities in a wind tunnel, as well as during GS and straight downhill skiing employing a Global Navigation Satellite System. On the basis of the wind tunnel measurements, a linear regression model of drag coefficient multiplied by cross-sectional area as a function of shoulder height was established for each skier (r > 0.94, all P
To evaluate the occurrence of arrhythmias and silent ischaemia during a prolonged exhaustive exercise in cold climate conditions, we monitored 37 healthy middle-aged men (age 40-56 years) who were randomly selected from participants of a ski marathon. Completing the 75-90 km race took 7-12 h. The highest and lowest mean hourly heart rates during skiing were 150 +/- 9 (mean +/- SD) and 138 +/- 11 beats.min-1. The maximum heart rate was 161 +/- 9 beats.min-1, and occurred in most skiers during the first hour. Ventricular premature complexes (VPCs) were present in 33 of 37 men (89%) with a median frequency of five beats during skiing (range 0-425). Complex forms occurred in eight men (22%), and atrial ectopics appeared in 33 of 35 participants (94%). The frequency of the arrhythmias did not increase over the skiing period. At control monitoring during a representative period the highest mean hourly heart rate was 74 +/- 12 beats.min-1 and VPCs were seen in 21 men (57%) at a median frequency of one beat during the control period (range 0-338) and complex forms occurred in three men (8%). Three men had asymptomatic ST segment depression of 0.2-0.3 mV lasting 2-10 min during the first hour of skiing. One of them had marginal ST segment depression (0.1 mV) at exercise electrocardiography, but all had normal results at exercise thallium scintigraphy and echocardiography. Thus, arrhythmias were significantly (P
This study compared overuse injuries, small abnormalities, and pain alone in different types of skiing and activity levels. Subjects were 45 ski high school athletes aged 15-19 years. We found the back and knees significantly more prone to activity-related injuries and pain than other body regions. Thirty subjects (67%) had low back pain on the first examination, and 17 had pain caused by overuse of the back. This was more frequent among active, young competitive boys in the cross-country skiing group, with mature height less than 99%, than among noncompetitive boys in the same group or among the alpine skiers. Neck pain was reported only by girls. Eight subjects had low back pain related to small abnormalities. The subjects were given counseling about training and physiotherapy. The 1-year follow-up found a significant reduction in back pain due to overuse injuries (from 17 to 3 subjects) and indistinct neck pain (from 10 to 2) but no reduction in pain in those with small abnormalities in the low back. Low back pain was common in young athletes, particularly in cross-country skiers. Excessively rapid progression of training and faulty technique increased back pain complaints from 36% when entering the school to 67% at the first examination. A proper evaluation and treatment of overuse injuries and accurate counseling of training types, volume, and progression reduced the low back pain problems to 29% of subjects 1 year later in spite of a maintained high activity level. A minimum entrance requirement to conditioning seems mandatory for students attending a ski high school.
INTRODUCTION: Asthma is frequently reported in endurance athletes, particularly in cross-country skiers. It has been reported that an exercise field test performed with the competitive type of exercise is the better for diagnosing asthma and bronchial hyperresponsiveness in athletes than bronchial provocation with methacholine. OBJECTIVE: The main objective was to compare an exercise field test consisting of a skiing competition with methacholine bronchial provocation in the diagnosis of asthma and bronchial hyperresponsiveness among skiers. METHODS: Twenty-four elite cross-country skiers from the Norwegian national teams (males/females = 16/8) were included in the study. The cumulative dose of inhaled methacholine causing a 20% fall in forced expiratory volume in 1 s (FEV1) (PD20) was compared with reduction in lung function (FEV1) >or= 10% from before to after an exercise field test consisting of a cross-country skiing competition, 10 km (males) and 7 km (females), respectively. RESULTS: Nine out of 24 (37.5%) athletes experienced a positive methacholine test (PD20 or= 10% after the exercise field test. A significant negative correlation was found between age and bronchial responsiveness, r = -0.47, P = 0.02. CONCLUSION: The methacholine bronchial provocation test is more sensitive than a sport specific exercise field test for identifying athletes with asthma and/or bronchial hyperresponsiveness.
OBJECTIVE: To investigate change in serum sodium concentration and its potential causes during a cold weather ultradistance race. DESIGN: Descriptive research. SETTING: A 100-mile (161-km) race over a snow-packed course in the Alaskan wilderness. Athletes competed in 1 of 3 divisions: foot, bike, or ski. PARTICIPANTS: Twenty athletes (11 runners, 6 cyclists, 3 skiers) volunteered for the study. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Subjects were weighed and had blood drawn for hematocrit, serum sodium, serum aldosterone, and plasma arginine vasopressin concentrations pre- and postrace. Fluid and sodium intake were determined by race dietary analysis. RESULTS: Serum sodium concentration decreased significantly prerace (140.8 +/- 1.2 mmol/L) to postrace (138.4 +/- 2.2 mmol/L), although no athletes were classified as hyponatremic. Mean weight loss was significant during the race (-1.2 kg), although 1 athlete maintained his weight, and 3 athletes gained small amounts of weight (0.2 kg, 0.2 kg, and 0.5 kg, respectively). Hematocrit decreased significantly prerace (42.2 +/- 3.5) to postrace (40.3 +/- 4.1). Plasma arginine vasopressin and serum aldosterone increased significantly during the race (2.6 +/- 0.7 to 6.0 +/- 4.6 pg/mL and 5.1 +/- 2.6 to 40.8 +/- 25.1 ng/dL, respectively). Fluid consumption was 300 +/- 100 mL/h, and sodium intake was 310 +/- 187 mg/h. CONCLUSIONS: Decreased serum sodium concentration after a cold weather ultradistance race was due to fluid overload caused by excessive fluid consumption. Current recommendations that ultradistance athletes consume 500 to 1000 mL/h may be too high for athletes competing in the extreme cold.
Harmful cardiac events occurs frequently after exercise. However, the cardiac autonomic regulation after vigorous exercise is not well known. This study was designed to assess heart rate (HR) variability before and after a 75 km cross-country skiing race. HR variability was assessed by using standard statistical measures along with spectral and quantitative Poincarè plot analysis of HR variability in 10 healthy male subjects (age 36 +/- 11 years). The average HR was at the same level 1 day after the race as before the race, but on the second day, HR was significantly lower (P
Hemoglobin data have been available from ski teams beginning from 1987, and from 1989 to 1999 we have followed hemoglobin values in elite cross-country skiers in international competitions. The mean values at the 1989 World Nordic Ski Championships were lower than population reference values, as would be expected from plasma volume expansion associated with endurance training. However, an increase, particularly in the maximal values, became obvious in 1994 and rose further in 1996. These extreme values provide both a health risk to the individual athlete and unfair competition. After a rule limiting hemoglobin values was introduced, the drop of the highest values was remarkable: among men 15 g/l (0.23 mmol/l) and among women 42 g/l (0.65 mmol/l). It would appear that the rule had achieved its goal of limiting extreme hemoglobin values. Yet the mean hemoglobin concentrations in men and women have continued to rise, suggesting the continued use of artificial methods to increase total hemoglobin mass.
PURPOSE: Roller skiing is frequently used in Nordic disciplines during the off-season periods. Recently, in-line skating has become a potential alternative. In the present study, the responses of heart rate, oxygen uptake, respiratory exchange ratio, and lactic acid concentration to roller skiing and in-line skating were compared in competitive biathletes. METHODS: Eight male subjects performed three tests with both devices on a hilly outdoor track. They were requested to adjust their speed in such a way that the following criteria were met: intensity 1, lactate concentration about 2 mmol x L(-1); intensity 2, lactate concentration about 4 mmol x L(-1); AND intensity 3, maximal speed. RESULTS: Though the subjects were not experienced in-line skaters, all managed to adjust the required intensities. This was achieved through increased velocities during in-line skating. Independent of the exercise intensity the differences in speed ranged between 1.0 and 1.4 m x s(-1). The relationships between lactic acid concentration, oxygen uptake, respiratory exchange ratio, and heart rate were not influenced by the test device. The respiratory exchange ratio amounted to 0.88, 0.95, and 1.02 for intensities 1 to 3, respectively. CONCLUSIONS: These results show that in-line skating can be regarded as an alternative to roller skiing for off-seasonal training in Nordic disciplines. A potential advantage of in-line skating is that aerobic training intensities can be obtained at competitive velocities.