Ann Magdalen Hegge’s research while affiliated with Mid Sweden University and other places

The present study investigated the contribution of performance on uphill, flat, and downhill sections to overall performance in an international 10-km classical time-trial in elite female cross-country skiers, as well as the relationships between performance on snow and laboratory-measured physiological variables in the double poling (DP) and diagonal (DIA) techniques. Ten elite female cross-country skiers were continuously measured by a global positioning system device during an international 10-km cross-country skiing time-trial in the classical technique. One month prior to the race, all skiers performed a 5-min submaximal and 3-min self-paced performance test while roller skiing on a treadmill, both in the DP and DIA techniques. The time spent on uphill (r = 0.98) and flat (r = 0.91) sections of the race correlated most strongly with the overall 10-km performance (both p < 0.05). Approximately 56% of the racing time was spent uphill, and stepwise multiple regression revealed that uphill time explained 95.5% of the variance in overall performance (p < 0.001). Distance covered during the 3-min roller-skiing test and body-mass normalized peak oxygen uptake (VO2peak) in both techniques showed the strongest correlations with overall time-trial performance (r = 0.66–0.78), with DP capacity tending to have greatest impact on the flat and DIA capacity on uphill terrain (all p < 0.05). Our present findings reveal that the time spent uphill most strongly determine classical time-trial performance, and that the major portion of the performance differences among elite female cross-country skiers can be explained by variations in technique-specific aerobic power.

Purpose: To characterize gender differences in power output, energetic capacity and exercise efficiency during whole-body (WP), upper-body (UP), and arm poling (AP). Methods: Ten male and ten female elite cross-country skiers, matched for international performance level, completed three incremental submaximal tests and a 3-min self-paced performance test on a Concept2 SkiErg. Power output, cardiorespiratory and kinematic variables were monitored. Body composition was determined by dual-energy X-ray absorptiometry. Results: The men demonstrated 87, 97 and 103 % higher power output, and 51, 65 and 71 % higher VO2peak (L min(-1)) than the women during WP, UP and AP, respectively, while utilizing ~10 % more of their running VO2max in all modes (all P < 0.001). The men had 35, 38 and 59 % more lean mass in the whole body, upper body and arms (all P < 0.001). The men exhibited greater shoulder and elbow extension at the start of poling and greater trunk flexion at the end of poling (all P < 0.05). The relationship between VO2 and power output did not differ between the men and women. Conclusions: Gender differences in power production and peak aerobic capacity increased sequentially from WP to UP to AP, coinciding with a greater portion of the muscle mass in the arms of the men. Although the men and women employed each poling technique differently, the estimated efficiency of double poling was independent of gender.

Purpose: To compare the physiological capacity and training characteristics of the world's six highest ranked female cross-country skiers (WC) with those of six competitors of national class (NC). Methods: Immediately before the start of the competition season, all skiers performed three 5-min submaximal stages of roller skiing on a treadmill for measurement of oxygen cost, as well as a 3-min self-paced performance test employing both the double poling (DP) and diagonal stride (DIA) techniques. During the 3-min performance tests, the total distance covered, peak oxygen uptake (VO2peak) and accumulated oxygen deficit were determined. Each skier documented the intensity and mode of their training during the preceding 6 months in a diary. Results: There were no differences between the groups with respect to oxygen cost or gross efficiency at the submaximal speeds. The WC skiers covered 6-7% longer distances during the 3-min tests and exhibited average VO2peak values of ~70 and ~65 mL·min·kg with DIA and DP, respectively, which were 10 and 7% higher than the NC skiers (all P<0.05). However, the accumulated oxygen deficit did not differ between groups. From May to October, the WC skiers trained a total of 532±73 hours (270±26 sessions) versus 411±62 hours (240±27 sessions) for the NC skiers. In addition, the WC skiers performed 26% more low-intensity and almost twice as much moderate-intensity endurance and speed training (all P<0.05). Conclusions: This study highlights the importance of a high oxygen uptake and the ability to utilize this while performing the different skiing techniques on varying terrain for female cross-country skiers to win international races. In addition, the training data documented here provide benchmark values for female endurance athletes aiming for medals.

Introduction: The anthropometric and physical differences between men and women should not only influence the capacity to generate power and energy, but may also lead to differences in technique in a whole-body endurance sport like cross-country skiing. Since the upper body plays a crucial role in this sport, specific training of the arms and trunk is of importance. However, little is presently known concerning gender differences in the technical execution of the double-poling movement and how this coincide with variations in exercise efficiency. Purpose: To characterize gender differences in the technical execution of upper body poling and exercise efficiency between whole-body (WP), upper-body (UP) and arm poling (AP) among elite cross-country skiers. Methods: Ten male and ten female elite cross-country skiers, matched for international performance level, completed three incremental submaximal tests and a 3-min all-out test on a Concept2 SkiErg in all poling modes. Power output was measured with the ergometer’s internal software. Respiratory variables were assessed employing open-circuit indirect calorimetry. Movement data from eleven passive reflective markers on the ergometer and body was captured by the Qualisys motion capture system. The regression lines of submaximal oxygen uptake on power output were used to compare exercise efficiency. Results: To produce the 87% (152±28 vs 285±34W in WP), 97% (110±19 vs 216±34W in UP) and 103% (69±12 vs 140±20W in AP) higher power outputs during the 3-min test, men exhibited shorter poling times and used greater shoulder and elbow extension at the start of poling (all P<0.05). There were no gender differences in the shoulder and elbow angles at the end of the poling phase. The hip angles did not differ between the men and women at the start of poling, but were significantly smaller for the men at the end of the poling phase, resulting in a larger trunk range of motion for the men (all P<0.05). The relationship between oxygen uptake and power output during the three submaximal sessions did not differ between the men and women for any of the poling modes. Conclusions: The higher power outputs of the men coincided with significant gender variability in the technical execution of all poling modes and a favourable distribution of muscle mass in arms. The tendency towards greater angular range of motion of the trunk shoulder and elbow joints executed over relatively less time among men indicate a more explosive poling technique compared with female skiers. However, the energetic cost of a given power was independent of gender for all modes.

In the current study, we evaluated the impact of exercise intensity on gender differences in upper-body poling among cross-country skiers, as well as the associated differences in aerobic capacity, maximal strength, body composition, technique and extent of training. Eight male and eight female elite skiers, gender-matched for level of performance by FIS points, carried out a 4-min submaximal, and a 3-min and 30-sec maximal all-out test of isolated upper-body double poling on a Concept2 ski ergometer. Maximal upper-body power and strength (1RM) were determined with a pull-down exercise. In addition, body composition was assessed with a DXA scan and training during the previous six months quantified from diaries. Relative to the corresponding female values (defined as 100%), the power output produced by the men was 88%, 95% and 108% higher during the submaximal, 3-min and 30-sec tests, respectively, and peak power in the pull-down strength exercise was 118% higher (all P<0.001). During the ergometer tests the work performed per cycle by the men was 97%, 102% and 91% greater, respectively, and the men elevated their cycle rate to a greater extent at higher intensities (both P<0.01). Furthermore, men had a 61% higher VO2peak, 58% higher 1RM, relatively larger upper-body mass (61% vs 56%) and reported considerably more upper-body strength and endurance training (all P<0.05). In conclusion, gender differences in upper-body power among cross-country skiers augmented as the intensity of exercise increased. The gender differences observed here are greater than those reported previously for both lower- and whole-body sports and coincided with greater peak aerobic capacity and maximal upper-body strength, relatively more muscle mass in the upper-body, and more extensive training of upper-body strength and endurance among the male skiers.

To study performance, physiological and biomechanical responses during repeated upper-body sprint exercise. Twelve male elite cross-country skiers performed eight 8-s maximal poling sprints with a 22-s recovery while sitting on a modified SkiErg poling ergometer. Force, movement velocity, cycle rate, work per cycle, oxygen saturation in working muscles and pulmonary oxygen uptake were measured continuously. A 3-min all-out ergometer poling test determined VO2peak, and 1 repetition maximum (1RM) strength was determined in a movement-specific pull-down. Average sprint power was 281 ± 48 W, with the highest power on the first sprint, a progressive decline in power output over the following four sprints, and a sprint decrement of 11.7 ± 4.1 %. Cycle rate remained unchanged, whereas work per cycle progressively decreased (P < 0.05). m. triceps brachii and m. latissimus dorsi were highly desaturated already after the first sprint (all P < 0.05), whereas the response was delayed for m. biceps brachii and m. vastus lateralis. Correspondingly, increases in VO2 mainly occurred over the first two sprints (P < 0.05) and plateaued at approximately 75 % of VO2peak. 1RM correlated with power during the first four sprints and with average sprint power (r = 0.71-0.80, all P < 0.05), whereas VO2peak correlated with power in the last three sprints (r = 0.60-0.71, all P < 0.05). The main decrement in upper-body sprint performance was evident in the first five sprints, followed by highly desaturated muscles and a plateau in pulmonary oxygen uptake already after the first 2-3 sprints. While high maximal strength seems important for producing power, aerobic capacity correlates with power in the last sprints.

To compare the speed and heart rate profiles during international skating and classical competitions in male and female world-class cross-country skiers. Four male and five female skiers performed individual time-trials of 15 km (men) and 10 km (women) in the skating and classical techniques on two consecutive days. Races were performed on the same 5-km course. The course was mapped with GPS and a barometer to provide a valid course and elevation profile. Time, speed and heart rate were determined for uphill, flat and downhill terrains throughout the entire competition by wearing a GPS and a heart rate monitor. Time in uphill, flat and downhill terrain was ~55, 15-20 and 25-30% of the total race time for both techniques and genders. The average speed differences between skating and classical skiing were 9 and 11% for men and women respectively; and these values were 12 and 15% for uphill, 8 and 13% for flat (all P<0.05) and 2 and 1% for downhill terrain. The average speed for men was 9 and 11% faster than women in skating and classical respectively; with corresponding numbers of 11 and 14% for uphill, 6 and 11% for flat, and 4 and 5% for downhill terrain (all P<0.05). Heart rate profiles were relatively independent of technique and gender. The greatest performance differences between the skating and the classical technique and between the two genders were found on uphill terrain. However, these speed differences could be explained by variations in exercise intensity.