The contribution from cross-country skiing and shooting variables for biathlon performance in sprint, individual and pursuit competitions

Summary Biathlon is an Olympic winter sport combining cross-country (XC) skiing in the skating technique with rifle marksmanship. Biathletes ski loops of 1.5-4 km with shooting between laps in either the prone or standing position. The cross-country (XC) skiing part of the competition is performed on XC-skiing tracks on undulating terrain differing between uphill, downhill and flat or varied terrain. The shooting takes place directly between each lap of skiing on a 50 m outdoor shooting range where the circular targets have hit areas of 45 mm in prone position and 115 mm in standing. Biathletes use 0.22 caliber rifles that the athletes carry on their back while skiing. In single-start races each shooting comprises of 5-shot-series in the prone or standing shooting. For each missed target at the shooting range, biathletes are either penalized with extra time (i.e. 60 s in the individual 15/20 km event) or a 150 m extra loop of skiing (~22s). Seven championship biathlon events exist with varying skiing distances for each shooting and penalty for missed targets across events. The overall purpose of this thesis was to study the contribution of the different race components in biathlon sprint, individual and pursuit races in both genders as well as the association between sprint race performance and laboratory measured capacities. In study I, the aim was to analyze to what degree the different race factors contributed to the overall performance in World Cup sprint races. The results revealed that course time was the most influential factor for overall performance in both sexes in sprint races explaining approximately 60% of the performance level difference. This was followed by shooting performance explaining more than 30% between a top-10 result and a result among 21st and 30th place. Shooting time and range time only contributed little or nothing to the overall performance in sprint races. In study II, we hypothesized that shooting performance would explain a larger part of the overall differences between performance groups in individual World Cup biathlon races than in sprint races due to the increased penalty time for each missed shot. Indeed, course time and penalty time contributed similarly to the performance-level differences whereas course time explained above 90% of the sex differences. In study III, the aim was to analyze the contribution of the different race components in pursuit World Cup competitions. The results show that 84% and 81% of all victories were achieved by athletes starting as number 5 or better among men and women. In most of the races investigated in men and women, 50% of the overall performance among top 30 athletes was explained by start time. In these races, penalty time was ranked as the second most important component. In a few other races, penalty time was ranked as the most important contributing component explaining on average 40% of the overall performance in these races. Penalty time was also the most contributing factor for the isolated pursuit race explaining 55-60% followed by course time explaining approximately 30% of the isolated pursuit race time. Standing shooting explained most of the variance in penalty time, but no difference in impact between the third and fourth shooting was found. Together these findings also highlight the importance of the shooting component and especially performance in the standing shooting to overall and isolated pursuit race performance. In study IV the aims were to investigate the contribution from overall XC-skiing performance, the performance in different terrain sections and shooting performance to the overall performance in a biathlon sprint race. The relationship between these variables and laboratory-measured capacities obtained during treadmill roller ski skating were also investigated. The results showed that the XC-skiing performance provided greatest impact on biathlon sprint performance, with most of the variance determined by XC-skiing performance in the uphill terrain sections. Furthermore, low rates of perceived exertion (RPE) and low relative heart rates (%HRmax) during submaximal constant speeds, as well as time-toexhaustion (TTE) during incremental roller skiing significantly predicted biathlon performance. Such laboratory-derived measures could therefore be used to distinguish biathletes of different performance levels and to track progress of their XC-skiing capacity. The overall conclusions are that course time is the most important race component for the overall performance in biathlon sprint races, that course time and penalty time are more similarly important in individual races than in sprint races and that start time explain most of the performance in pursuit races. Biathletes at World Cup level miss more targets in standing than in prone shooting but there is no sex difference in shooting performance (number of misses) except that women use more time for shooting than men. In addition, better performing athletes pace their races more evenly and gain most time in uphill sections of the race compared to lower performing athletes. Better course times in a sprint race was correlated to lower RPE, %HRmax as well as TTE from submaximal tests and a maximal test