| 1. |
- Hegge, Ann Magdalen, et al.
(författare)
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Are Gender Differences in Upper-Body Power Generated by Elite Cross-Country Skiers Augmented by Increasing the Intensity of Exercise?
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- 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 VO(2)peak, 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.
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| 2. |
- Jonsson, Malin, et al.
(författare)
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Biomechanical differences in double poling between sexes and level of performance during a classical cross-country skiing competition
- 2019
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Ingår i: Journal of Sports Sciences. - : Informa UK Limited. - 0264-0414 .- 1466-447X. ; 37:14, s. 1582-1590
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Tidskriftsartikel (refereegranskat)abstract
- Biomechanical differences in double poling (DP) between sex and performance level were investigated in female and male cross-country skiers during a classical race (10/15 km). Skiers were divided into faster and slower on basis of race performance: females faster (n=20), females slower (n=20), males faster (n=20), and males slower (n=20). Based on video analysis while DP in a flat section of the track, joint and pole angles at pole plant (PP) and pole-off, cycle characteristics and the use and coordination pattern of heel-raise (raise of heels from the ground to have a higher body position at PP) were analysed. Faster females and males had 4.3% and 7.8% higher DP velocity than their slower counterparts (both P<0.001). Faster males had 6.5% longer cycles than slower males (P<0.001). Faster skiers stopped heel-raise later than slower skiers (females: 2.0±3.4% vs. −1.0±3.5%, P<0.05; males: 3.9±2.4% vs. 0.8±3.2% of cycle time in relation to PP, P<0.001). At PP, faster skiers and male skiers had a smaller pole angle and greater ankle to hip and ankle to shoulder angle with respect to vertical, resulting in a more distinct forward body lean. However, the majority of the differences are likely due to higher DP velocity.
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| 3. |
- Jonsson, Malin, et al.
(författare)
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Biomechanical differences in double poling (DP) for world- and national-class female elite cross-country (XC) skiers during a 10-km classical race
- 2016
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Ingår i: Proceedings ICSS in St. Christoph am Arlberg, Austria.
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Konferensbidrag (refereegranskat)abstract
- Introduction The DP technique of classical XC-skiing involves both the upper and lower body (Holmberg et al.,2005) and has become more important the last years with skiers using exclusively DP during some competitions. Our purpose was to characterize biomechanical differences in DP by world- (WC) and national-class (NC) women skiers. Methods The participants were 40 elite female XC skiers (20 WC and 20 NC) who competed in the 10-km classical race at the Norwegian National Championships, 2016. On a flat measurement section (22 m long) 0.8 km from the start, the skiers employed DP only and were video-filmed (Panasonic GH4, 96 Hz). Three DP cycles were analyzed using the Kinovea software (France, v 8.25) for joint and pole angles at pole plant (PP) and pole off (PO), as well as cycle length (CL) and rate (CR), and poling (PT) and swing times (ST). Results The total racing time for the WC-group was 10.5% faster than for the NC-skiers, with no differences in CL, CR, PT or ST. The WC-group skied faster on the flat section (6.30±0.23 vs 6.04±0.25 m/s) and exhibited a smaller ankle-shoulder angle relative to horizontal at PP (73.0±1.8 vs 75.0±1.5°) and a smaller hip angle at PO (62.7±5.2 vs 69.1±6.4°) with no difference in minimal trunk angle with respect to horizontal (19.2±3.2 vs 21.7±4.8°). 27 of the skiers (15 WC and 12 NC) used active heel raise to create force. There was a difference between the groups for when the heel raise ended, with the NC-group stopping just before PP and the WC-group after. No difference between the groups were found for when the heel raise started . There was a negative correlation between DP velocity and total racing time (r = -0.48, p<0.05) and a positive correlation between total racing time and the ankle-shoulder angle relative to horizontal at PP (r = 0.54, p<0.01), the hip angle at PO (r = 0.51, p<0.01) and minimal trunk angle relative to horizontal during the cycles (r = 0.41, p<0.01). Discussion The WC-group had 4.1% higher DP velocity which correlated with total racing time. Moreover, the finding that faster skiers have a more forward lean of the body at PP and a better timing of the ending of the heel raise, indicates that they can bring more bodyweight on their poles at PP. The WC-group had a smaller hip angle at PO which is in line with the findings of Lindinger et al.(2009). This study shows the importance of a high relative velocity during DP sections of the track and highlights the benefit of a more forward body position at PP to create higher DP velocity in female XC skiers. References Holmberg, H.C., Lindinger, S., Stöggl, T., Eitzlmair, E. & Müller, E. (2005). Biomechanical analysis of double poling in elite cross-country skiers. Med Sci Sports Exerc, 37(5), 807-818 Lindinger, S., Stöggl, T., Müller, E. & Holmberg, H.C. (2009). Control of speed during the double poling technique performed by elite cross-country skiers. Med Sci Sports Exerc, 41(1), 210-220
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| 4. |
- Mikkilä, Saija, et al.
(författare)
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A 15-year follow-up study of hip bone mineral density and associations with leisure time physical activity : the Tromsø Study 2001-2016
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The aim was to investigate the long-term association between leisure time physical activity and hip areal bone mineral density (aBMD), in addition to change in hip aBMD over time, in 32-86 years old women and men.Methods: Data were retrieved from the 2001, 2007-2008, and 2015-2016 surveys of the Tromsø Study, a longitudinal population study in Norway. Leisure time physical activity was assessed by the four-level Saltin-Grimby Physical Activity Level Scale which refers to physical exertion in the past twelve months. Hip aBMD was assessed by Dual-Energy X-ray Absorptiometry. Linear Mixed Model analysis was used to examine long-term associations between physical activity and hip aBMD (n = 6324). In addition, the annual change in hip aBMD was analyzed in a subsample of 3199 participants.Results: Physical activity was significantly and positively associated with total hip aBMD in the overall cohort (p<0.005). Participants who reported vigorous activity had 28.20 mg/cm2 higher aBMD than those who were inactive (95% CI 14.71; 41.69, controlled for confounders), and even light physical activity was associated with higher aBMD than inactivity (8.32 mg/cm2, 95% CI 4.89; 11.76). Associations between physical activity and femoral neck aBMD yielded similar results. Hip aBMD decreased with age in both sexes, although more prominently in women. From 2001 to 2007-2008, aBMD changed by -5.76 mg/cm2 per year (95% CI - 6.08; -5.44) in women, and -2.31 mg/cm2 (95% CI -2.69; -1.93), in men. From 2007-2008 to 2015-2016, the change was -4.45 mg/cm2 per year (95% CI -4.84; -4.06) in women, and -1.45 mg/cm2 (95% CI -1.92; -0.98) in men.Conclusions: In this cohort of adult men and women, physical activity levels were positively associated with hip aBMD in a dose-response relationship. Hip aBMD decreased with age, although more pronounced in women than men. Copyright:
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| 5. |
- Osborne, John O., et al.
(författare)
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Annual Volume and Distribution of Physical Training in Norwegian Female Cross-Country Skiers and Biathletes : A Comparison Between Sports, Competition Levels, and Age Categories- The FENDURA Project
- 2024
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Ingår i: International Journal of Sports Physiology and Performance. - : Human Kinetics. - 1555-0265 .- 1555-0273. ; 19:1, s. 19-27
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe and compare the annual physical training characteristics between Norwegian female cross-country (XC) skiers and biathletes across competition levels and age categories. Methods: Daily training sessions for 1 year were recorded for 45 XC skiers and 26 biathletes, comprising international/national team (inter[national]) and nonnational/regional team members (nonnational) of both junior and senior age. Endurance, strength, flexibility, speed, and power training sessions were recorded. Data included exercise modality, intensity, and duration. Data were analyzed using linear mixed-effects models. Results: The total annual physical training volume consisted of -90% endurance training for both groups, although XC skiers had significantly higher total volumes (-10%; P = .003; d= 0.78) than biathletes. Senior XC skiers performed more training hours of skiing and/or roller skiing compared with biathletes over the season. However, biathletes compensated for this lower volume by more skating and a higher proportion of endurance training as skiing (81% [17%]) compared with XC skiers (68% [16%]; P < .001; d= 0.94). Overall, (inter)national-level athletes completed a higher annual training volume than non-national-level athletes (740 [90] h vs 649 [95] h; P= .004;d = 0.81). Although juniors reported less endurance volume than seniors, they maintained a relatively stable level of endurance training across the preparatory and competition period, unlike senior athletes. Conclusions: The higher annual physical training volume by XC skiers compared with biathletes is likely caused by the different demands of the 2 sports; XC skiing necessitates training for 2 skiing styles, while biathlon requires additional shooting practice. However, biathletes compensate with a higher proportion of ski training, particularly in the skating technique.
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| 6. |
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| 7. |
- Sandbakk, Oyvind, et al.
(författare)
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Endurance Training and Sprint Performance in Elite Junior Cross-Country Skiers
- 2011
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Ingår i: Journal of Strength and Conditioning Research. - 1064-8011 .- 1533-4287. ; 25:5, s. 1299-1305
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present study was to investigate the relationship between aerobic characteristics and sprint performance, and the effects of high-intensity endurance training in cross-country skiing. Ten male and five female elite junior cross-country skiers performed an 8-week intervention training period. The intervention group (IG, n = 7) increased the volume of high-intensity endurance training performed in level terrain, whereas the control group (CG, n = 8) continued their baseline training. Before and after the intervention period, the skiers were tested for 1.5 km time-trial performance on roller skis outdoors in the skating technique. Maximal oxygen uptake (VO2max) and oxygen uptake at the ventilatory threshold (VO2VT) were measured during treadmill running. VO2max and VO2VT were closely related to sprint performance (r = ~0.75, both p < 0.008). The IG improved sprint performance, VO2max and VO2VT from pre to post-testing, and improved sprint performance and VO2VT when compared to the CG (all p < 0.01). This study shows a close relationship between aerobic power and sprint performance in cross-country skiing, and highlights the positive effects of high-intensity endurance training in level terrain.
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| 8. |
- Stoeggl, Thomas L., et al.
(författare)
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Pacing, Exercise Intensity, and Technique by Performance Level in Long-Distance Cross-Country Skiing
- 2020
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Long-distance cross-country skiing (XCS) has gained increased popularity within the past decades. However, research about long-distance XCS is limited; therefore, the aim of this study was to analyze the intensity distribution, technique application, and pacing strategies during long-distance XCS racing. Methods Heart rate (HR) and section skiing speeds of 9 elite (ranked 1-100) and 10 amateur skiers (ranked 101-1,500) during the 90-km Vasaloppet race were collected. In addition, during the first uphill, the first 1,000 skiers were video-recorded to analyze the applied skiing strategy (e.g. grip-waxed skis versus exclusive double poling). Results Mean race intensity was 82% of maximal HR and was not different between performance groups even though elite skiers skied similar to 15% faster than amateurs. There was an interaction effect of section x group with a pronounced decrease in HR in amateurs compared with more even pacing in elite skiers (0.13 vs. 0.04% decrease/km) and skiing at higher percentage in the high-intensity zones in elite compared with amateurs (46 vs. 24%). Ninety-eight percent of the top 100 skiers and 59% of the first 1,000 skiers used exclusively double poling. Conclusion Elite and amateur skiers ski at comparable mean race exercise intensity, but they have clear differences in skiing speed. The difference in the pacing profiles between elite and amateur skiers (more even vs. distinct positive pacing) demonstrate the greater capacity of the former with respect to physiological capacity and highlights that amateurs seem to start too fast according to their capacities. The exclusive application of the double poling technique is no longer a phenomenon of elite skiers but is widely used among the top 1,000 ranked skiers.
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| 9. |
- Stöggl, Thomas, et al.
(författare)
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Impact of incline, sex and level of performance on kinematics during a distance race in classical cross-country skiing
- 2018
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Ingår i: Journal of Sports Science and Medicine (JSSM). - 1303-2968. ; 17:1, s. 124-133
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Tidskriftsartikel (refereegranskat)abstract
- Here, female and male elite cross-country (XC) skiers were compared on varying terrain during an official 10-km (women) and 15-km (men) Norwegian championship race. On the basis of race performance, 82 skiers were classified as fast (FS) (20 women, 20 men) or slower (SS) (21, 21) skiers. All were video recorded on flat (0°), intermediate (3.5°), uphill (7.1°) and steep uphill (11°) terrain during the race at a distance of 0.8, 1.2, 2.1 and 7.1 km from the start, respectively. All skiers employed exclusively double-poling (DP) on the flat section and, except for the male winner, exclusively diagonal stride (DIA) on the uphill sections. On the intermediate section, more men than women utilized DP and fewer DIA (p = 0.001), with no difference in kick double-poling (DPK). More FS than SS utilized DPK and fewer DIA (p = 0.001), with similar usage of DP. Males skied with faster and longer cycles but lower cycle rate compared with females (p < 0.001), with largest absolute sex differences on flat terrain (p < 0.001) and largest relative differences for cycle velocity and length on intermediate and uphill terrain. External power output rose with increasing incline, being higher for men and FS (p < 0.001). Cycle velocity on flat terrain was the best predictor of mean race velocity for the men, while cycle velocity on steep uphill was the best predictor for the women (both p < 0.001). In conclusion, incline, sex and level of performance influenced cycle characteristics and power output. Greatest absolute sex gap was on flat terrain, whereas the relative difference was greatest on intermediate and steep uphill terrain. We recommend usage of more DP and/or DPK, and less DIA and fewer transitions between techniques on intermediate terrain. Predictors of race performance are sex specific with greatest potential for enhancing performance on flat terrain for men and on steep uphill terrain for women.
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| 10. |
- Welde, Boye, et al.
(författare)
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The pacing strategy and technique of male cross-country skiers with different levels of performance during a 15-km classical race
- 2017
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- In this study the pacing strategy, cycle characteristics and choice of technique of elite male cross-country (XC) skiers during a three-lap, 15-km classical race with interval start were measured. During the Norwegian Championships in 2016, fast (n = 18, age: 26±4 yr; height: 182±4 cm; body mass: 78±3 kg (means±SD)) and slow skiers (n = 18, age: 22±2 yr; height: 183±5 cm; body mass: 78±6 kg) were video recorded on flat (0), intermediate (3.5) and uphill sections (7.1) of the first and final laps. All skiers adopted a positive pacing strategy, skiing more slowly (11.8%) with shorter cycles (11.7%) on the final than first lap (both p<0.001; pη2 = 0.93 and 0.87, respectively). The fast skiers were 7.0% faster overall (p<0.001, d = 4.20), and 6.1% (p<0.001, d = 3.32) and 7.0% (p<0.001, d = 3.68) faster on the first and final laps, respectively, compared to slower skiers. On all sections of both laps, the fast skiers exhibited 9.5% more rapid (pη2 = 0.74) and 8.9% (pη2 = 0.48) longer cycles (both p<0.001). On intermediate terrain, the fast skiers employed primarily double poling (DP, 38.9% on the first lap) and double poling with a kick (DPKICK, 50% on the final lap). In contrast, the slow skiers utilized for the most part DP alone (lap 1: 33.3%, lap 3: 38.9%) or in combination with other techniques (lap 1: 33.3%, lap 3: 38.9%) and decreased their usage of DPKICK from 27.8% on the first to 16.7% on the final lap. Skiing velocity on flat and intermediate terrain proved to be the best predictor of race performance (p<0.001). In conclusion, during a 15-km classical XC skiing race, velocity and cycle length decreased from the first to the final lap, most extensively on flat terrain and least uphill. Moreover, on the intermediate sections the fast and slow skiers chose to use different techniques.
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