Nordic Skiers Research Articles

Ventilatory response pattern of Nordic skiers during simulated poling

Cross-country ski poling is a distinctive exercise imposed by biomechanical motion which may influence the breathing pattern. To examine the ventilatory patterns of competitive cross-country skiers, the pulmonary function of nine male master level skiers was studied during simulated bilateral synchronous and asynchronous arm poling and upright leg cycling. Physiological and ventilatory responses during arm and leg exercise were compared on a Biokinetic arm ergometer and Monark bicycle. At similar levels of oxygen consumption, minute ventilation (VE) was lower for leg cycling than for the arm exercise modes. Heart rate was significantly higher (P < 0.05) during bilateral synchronous poling than for either bilateral asynchronous poling or leg cycling. Leg cycling elicited a higher tidal volume (VT) than either of the arm poling modes (1.8 vs 1.7 and 1.6 l). Breathing frequency (fR) was significantly higher (P < 0.05) for both arm exercise modes when compared to leg cycling (41 and 42 vs 27 breaths min-1). Frequency of strokes per breath (fS/fR) was significantly higher (P < 0.01) while cycling compared to synchronous arm work. The mean ratio of fS/fR per minute was 1.1:1 and 1.7:1 for arm exercise and leg cycling, respectively. Bilateral synchronous arm poling invoked a similar VE, lower VT and higher fR than bilateral asynchronous poling or leg cycling. These results demonstrate that ventilatory responses to arm poling are different from those to upright cycle exercise. There was a greater reliance during poling upon fR to maintain VE.

Mechanical Power Output and Estimated Metabolic Rates of Nordic Skiers During Olympic Competition

This paper explores whether there may be useful information in estimates of metabolic rates obtained from biomechanical calculations of mechanical power output. Thirteen men were analyzed as they passed a camera on each of three laps on an 11.8° uphill in the 30-km classical technique Olympic Nordic ski event. A 15-segment model was constructed; velocity, stride length, stride rate, mechanical power output, and from this latter measure an estimate of oxygen consumption, were obtained. The average lap velocity was 5.65 m•s−1 (20 km•hr−1), the film site velocity was 2.58 m•s−1, and the correlation between them was 0.75. There were no significant differences from lap to lap in any variable, nor were there dramatic differences between the skiers in the top 14 compared with those finishing in 35th place or slower in stride length or stride rate. However, the faster skiers had estimated VO2 from 80 to 112 ml•kg−1 • min−1 on most laps while the slower skiers had values from 53 to 77. If a VO2 estimated from biomechanical data can ultimately be shown to be accurate, a rather useful tool may have been identified for coaches, athletes, and sport scientists that can be used during competition in endurance events.

Body composition, body size estimation, and attitudes towards eating in male college athletes.

A number of different parameters relating to eating history and body composition were examined in male college athletes during the course of an athletic season. Wrestlers, who often lose weight to meet the requirements of the sport, were compared with other athletes (swimmers, nordic skiers) who typically maintain weight during vigorous training. By the end of the athletic season, the wrestlers had reduced body weights and reported a reduction in caloric intakes. Wrestlers scored higher than swimmers and nordic skiers on scales measuring dietary restraint and attitudes towards eating (EAT). The groups differed primarily on items dealing with fluctuations in body weight and with dieting behaviors. There were no significant differences between groups on the estimates of body size and no effect of seasonal training. However, a small subsample of the wrestlers who scored high on the restraint and EAT scales also showed distortions in estimates of body size. Wrestlers may represent a population at risk for the newly reported sports-induced disturbances in eating.

Nutrient Intake of Elite Male and Female Nordic Skiers.

In brief: This study of 13 male and 14 female members of the US Nordic Ski Team was conducted to analyze the nutrient content of their diet. The skiers recorded four sets of three-day dietary data during a year of training and competition. The results showed high calorie intake, as expected. However, fat intake was higher and carbohydrate intake lower than recommended amounts for optimal health and athletic performance. Iron intake by female skiers consistently failed to meet recommended levels, while cholesterol intake exceeded levels considered optimal. Intake of other nutrients reviewed in this report easily met recommended levels.

Immune parameters in athletes before and after strenuous exercise

Secretory IgA levels were studied in nationally ranked Nordic skiers before and after the national cross-country races held in February 1981. Comparing the skiers with age-matched controls, there was significantly lower level of salivary IgA before the race. Concentrations of IgA decreased further following the competition (50 kn for males; 20 km for females) to very low levels. There also were a significant increase in the percentage of B lymphocytes and a decrease in the null population (non-T, non-B) in the athletes after the race compared with the controls. The mechanism responsible for these changes is unknown, but the low salivary IgA levels may result from depletion of nasal fluid and/or malfunction of the mucosal plasma cells due to a decrease temperature in the mucous membranes. We speculated that a temporary antibody deficiency on the mucosal surface might lead to a susceptibility to acquiring viral and bacterial infections, especially during the interval immediately following strenuous exercise.

Cross-Country Skiing

<h3>To the Editor.—</h3> Nordic skiing is an enjoyable sport, but as it becomes more popular, people who are less experienced and in poorer physical condition will be involved with an expected increase in physical injury and death. The report by Lyons and Porter (239:334, 1978) dealt with a variety of injuries that were the result of falls while skiing. Perhaps as important are the serious problems of hypothermia, frostbite, and avalanche. Nordic skiers are generally not well enough aware of potential avalanche hazards, and with long enough exposure, even the most experienced skier can have some close calls. Unlike the avalanche victim at a populated ski resort, the Nordic skier who is buried must rely on his companions to find him in time. Frostbite and hypothermia can affect even experienced skiers. Two physician friends of mine, both experienced mountaineers and skiers, were caught in a whiteout while on a day

Body Composition and Somatotype of Male and Female Nordic Skiers

Abstract Body composition and somatotype characteristics were determined from measurements taken on 11 men and 5 women who were members of the U. S. Nordic Ski Team and in summer training during the summer of 1975. Mean body composition characteristics for men were height, 179.0 cm; weight, 71.8 kg; density, 1.085 g/ml; relative fat, 7.2%; and lean body weight (LBW), 67.1 kg. Respective means for women were 164.5 cm, 56.9 kg, 1.062 g/ml, 16.1%, and 48.6 kg. Both groups were very lean in comparison with nonathletic populations and were comparable to the leanest athletes of both sexes. Anthropometric measurements for both sexes showed small values for measures of variance (SD, range, coefficient of variation) suggesting that the subjects represented a select body type. Mean somatotypes (Heath-Carter anthropometric method) for men and women were 1.95-4.45-3.00 (ectomorphic mesomorph) and 3.5-4.3-2.3 (endomorphic mesomorph). Somatotypes for each sex were confined to a small area of the somatochart, again sugg...