Search

Background and Aims: Winter endurance athletes have a high prevalence of exercise‐induced bronchoconstriction (EIB) and asthma, probably due to repeated and prolonged inhalation of cold and dry air. Heat‐ and moisture‐exchanging devices (HME) warm and humidify inhaled air and prevent EIB. The aim of this study was to share cross‐country skiers and biathletes' experiences of training and competition in low temperatures, views on temperature limits, usage of HME, and consequences of cold exposure on their health. Methods: Eleven Swedish World Championship or Olympic medalists in cross‐country skiing and biathlon were interviewed and transcripts were analyzed using qualitative content analysis. Results: Participants described how cold temperatures predominantly affected the airways, face, and extremities. During training, extreme cold was managed by choosing warmer clothing, modification of planned sessions, use of HME, delaying training, or changing location. In competition, participants described limited possibility for such choices and would prefer adjustment of existing rules (i.e., more conservative temperature limits), especially since they understood elite skiing in low temperatures to present an occupational hazard to their health. Participants had at times used HMEs during training in cold environments but described mixed motives for their use—that HMEs warm and humidify cold inhaled air but introduce additional resistance to breathing and can cause problems due to mucus and ice build‐up. Skiers also perceived that they had become more sensitive to cold during the latter part of their careers. Conclusions: The present study gives a unique insight into the "cold" reality of being an elite athlete in skiing and biathlon. Cold exposure results in negative health consequences that are preventable, which means that rules must be followed, and organizers should acknowledge responsibility in protecting athletes from occupational hazards. Development of evidence‐based guidelines for protection of athletes' respiratory health should be a focus for future translational research. Key points: Most former elite skiers had experience of using heat‐ and moisture‐exchanging devices and felt they were able to protect the airways from damage, but that there was potential for improved ergonomics.Skiers expressed that current competition temperature limits may be too low to protect athletes' health.Skiers cited diminished responsibility for their own health when partaking in competitions than their own training; in competitions, they were likely to participate so long as the race was going ahead.The "athletes voice" on training and competing in the cold should be considered by other stakeholders in winter sports. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the effects of aerodynamic drag and drafting on propulsive force (F PROP), drag area (C D A), oxygen cost (V˙O2), metabolic rate (E ˙), and heart rate (HR) during roller skiing on a treadmill in a wind tunnel using the double poling technique. A secondary aim was to investigate the effects of wind versus no-wind test conditions on the same physiological parameters. Methods: Ten subjects of each gender participated in the experiments. One pair of skiers of the same gender roller skied simultaneously in line with the air flow; the distance between the skiers was ~2.05 m. Each pair was tested as follows: I) with wind, leading; II) with wind, drafting; and III) without wind. The treadmill inclination was 0° throughout the tests. For the wind conditions, the air velocity was similar to the treadmill belt speed: 3 to 7 m·s−1 for men and 3 to 6 m·s−1 for women. Results: Drafting resulted in significantly (P < 0.05) lower F PROP, C D A , V˙O2, and E ˙, compared with leading, for both genders at racing speed but not at lower speeds, whereas HR was only affected for the male skiers at racing speed. The test without wind resulted in significantly lower F PROP, V˙O2, and E ˙ at all tested speeds compared with the tests with wind present, whereas HR was lower only at higher speeds. Conclusions: At racing speed, but not at lower speeds, the positive effects of drafting behind a skier during double poling were obvious and resulted in a lower F PROP, C D A , V˙O2, E ˙, and HR. Tests without wind present put even lower demands on the skiers' physiology, which was also evident at lower speeds. [ABSTRACT FROM AUTHOR]

Some of the shooting training that biathletes implements takes place indoors, even in hotel rooms or at home, through so-called “dry firing” training. It involves imitating shooting at a target with real rifle but without ammunition, when the result is evaluated by various electronic devices counting the number of virtual hits. But dry firing cannot adequately represent real shooting, as it does not produce any rifle recoil, which significantly limits its value for the training. To reach a higher realism of the dry firing training a system mimicking the weapon recoil is therefore needed. Present research aims to overcome an existing lack of data on the dynamics of small caliber rifles recoil dynamics. Present paper describes first measurement results acquired in the controlled environment of the shooting range. Two types of experiments were carried out with firing freely suspended rifle and when backed with the force measurement device (load cell). Average recoil peak force values were reaching 5 kg, rising from zero for about 10-15 ms and keeping altogether for about 30-40 ms. Corresponding energy going into the recoil motion of the rifle is found to be about 390 J. The measured values provide an adequate input for designing the devices mimicking the biathlon weapon recoil in dry firing training. [ABSTRACT FROM AUTHOR]

The article discusses research which was conducted to compare skiing economy and efficiency in recreational and elite cross-country skiers. Researchers evaluated skiers who performed roller skiing on a treadmill. They found that the elite cross country skiers had better skiing economy and higher gross efficiency than the recreational skiers and that the senior elite had better economy and higher efficiency than their junior counterparts.

The aim of this study was to test the hypothesis that a combined relaxation (applied tension release, ATR) and specific shooting training regimen may enhance shooting ability of biathlon athletes. Seven biathletes of high national level were randomized into an experimental group (age 20 ± 5 years; Vo 2max 60 ± 8 mL kg− 1 min− 1) and were asked to add this special training intervention to their regular training for 10 weeks, while five other biathletes served as controls (age 19 ± 2 years; Vo 2max 57 ± 10 mL kg− 1 min− 1). The shooting ability of the subjects was assessed before and after the intervention at rest and after roller skiing on a treadmill in a laboratory-based competition simulating assessment. After the intervention period, the experimental group demonstrated a significantly enhanced shooting performance compared to the control group. No changes in Vo 2max or in heart rate and Vo 2 responses were observed before and after the intervention in either group and there were no differences between the groups in these parameters. Thus, the preliminary conclusion is that a combination of ATR and specific shooting training seems to be instrumental in enhancing the shooting performance in biathlon. [ABSTRACT FROM AUTHOR]

A program for numerical simulation of a whole ski race, from start to finish, is developed in MATLAB. The track is modelled by a set of cubical splines in two dimensions and can be used to simulate a track in a closed loop or with the start and finish at different locations. The forces considered in the simulations are gravitational force, normal force between snow and skis, drag force from the wind, frictional force between snow and ski and driving force from the skier. The differential equations of motion are solved from start to finish with the Runge-Kutta method. Different wind situations during the race can be modelled, as well as different glide conditions on different parts of the track. It is also possible to vary the available power during the race. The simulation program's output is the total time of the race, together with the forces and speed during different parts of the race and intermediate times at selected points. Some preliminary simulations are also presented. [ABSTRACT FROM AUTHOR]

Asthma is highly prevalent among winter endurance athletes. This "occupational disease" of cross-country skiers, among others, was acknowledged during the 1990s, with the pathogenesis attributed to repeated and prolonged exposure to cold, dry air combined with high rates of ventilation during exercise. Nevertheless, more than 25 years later, the prevalence of asthma among Scandinavian cross-country skiers is unchanged, and prevention remains a primary concern for sports physicians. Heat-and-moisture-exchanging breathing devices (HMEs) prevent exercise-induced bronchoconstriction in subjects with pre-existing disease and may have potential as a preventative intervention for healthy athletes undertaking training and competition in winter endurance sports. Herein we firstly provide an overview of the influence of temperature and humidity on airway health and the implications for athletes training and competing in sub-zero temperatures. We thereafter describe the properties and effects of HMEs, identify gaps in current understanding, and suggest avenues for future research., (Copyright © 2020 Hanstock, Ainegren and Stenfors.)