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Hebert-Losier, Kim
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Publications (10 of 36) Show all publications
Hebert-Losier, K., Zinner, C., Platt, S., Stöggl, T. & Holmberg, H.-C. (2017). Factors that Influence the Performance of Elite Sprint Cross-Country Skiers. Sports Medicine, 47(2), 319-342
Open this publication in new window or tab >>Factors that Influence the Performance of Elite Sprint Cross-Country Skiers
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2017 (English)In: Sports Medicine, ISSN 0112-1642, E-ISSN 1179-2035, Vol. 47, no 2, p. 319-342Article in journal (Refereed) Published
Abstract [en]

Background: Sprint events in cross-country skiing are unique not only with respect to their length (0.8–1.8 km), but also in involving four high-intensity heats of ~3 min in duration, separated by a relatively short recovery period (15–60 min). Objective: Our aim was to systematically review the scientific literature to identify factors related to the performance of elite sprint cross-country skiers. Methods: Four electronic databases were searched using relevant medical subject headings and keywords, as were reference lists, relevant journals, and key authors in the field. Only original research articles addressing physiology, biomechanics, anthropometry, or neuromuscular characteristics and elite sprint cross-country skiers and performance outcomes were included. All articles meeting inclusion criteria were quality assessed. Data were extracted from each article using a standardized form and subsequently summarized. Results: Thirty-one articles met the criteria for inclusion, were reviewed, and scored an average of 66 ± 7 % (range 56–78 %) upon quality assessment. All articles except for two were quasi-experimental, and only one had a fully-experimental research design. In total, articles comprised 567 subjects (74 % male), with only nine articles explicitly reporting their skiers’ sprint International Skiing Federation points (weighted mean 116 ± 78). A similar number of articles addressed skating and classical techniques, with more than half of the investigations involving roller-skiing assessments under laboratory conditions. A range of physiological, biomechanical, anthropometric, and neuromuscular characteristics was reported to relate to sprint skiing performance. Both aerobic and anaerobic capacities are important qualities, with the anaerobic system suggested to contribute more to the performance during the first of repeated heats; and the aerobic system during subsequent heats. A capacity for high speed in all the following instances is important for the performance of sprint cross-country skiers: at the start of the race, at any given point when required (e.g., when being challenged by a competitor), and in the final section of each heat. Although high skiing speed is suggested to rely primarily on high cycle rates, longer cycle lengths are commonly observed in faster skiers. In addition, faster skiers rely on different technical strategies when approaching peak speeds, employ more effective techniques, and use better coordinated movements to optimize generation of propulsive force from the resultant ski and pole forces. Strong uphill technique is critical to race performance since uphill segments are the most influential on race outcomes. A certain strength level is required, although more does not necessarily translate to superior sprint skiing performance, and sufficient strength-endurance capacities are also of importance to minimize the impact and accumulation of fatigue during repeated heats. Lastly, higher lean mass does appear to benefit sprint skiers’ performance, with no clear advantage conferred via body height and mass. Limitations: Generalization of findings from one study to the next is challenging considering the array of experimental tasks, variables defining performance, fundamental differences between skiing techniques, and evolution of sprint skiing competitions. Although laboratory-based measures can effectively assess on-snow skiing performance, conclusions drawn from roller-skiing investigations might not fully apply to on-snow skiing performance. A low number of subjects were females (only 17 %), warranting further studies to better understand this population. Lastly, more training studies involving high-level elite sprint skiers and investigations pertaining to the ability of skiers to maintain high-sprint speeds at the end of races are recommended to assist in understanding and improving high-level sprint skiing performance, and resilience to fatigue. Conclusions: Successful sprint cross-country skiing involves well-developed aerobic and anaerobic capacities, high speed abilities, effective biomechanical techniques, and the ability to develop high forces rapidly. A certain level of strength is required, particularly ski-specific strength, as well as the ability to withstand fatigue across the repeated heats of sprint races. Cross-country sprint skiing is demonstrably a demanding and complex sport, where high-performance skiers need to simultaneously address physiological, biomechanical, anthropometric, and neuromuscular aspects to ensure success.

National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-29766 (URN)10.1007/s40279-016-0573-2 (DOI)000393332100009 ()27334280 (PubMedID)2-s2.0-84975493645 (Scopus ID)
Note

First Online: 22 June 2016

Available from: 2016-12-22 Created: 2016-12-22 Last updated: 2017-12-14Bibliographically approved
Lussiana, T., Hebert-Losier, K., Millet, G. P. & Mourot, L. (2016). Biomechanical Changes During a 50-minute Run in Different Footwear and on Various Slopes. Journal of Applied Biomechanics, 32(1), 40-49
Open this publication in new window or tab >>Biomechanical Changes During a 50-minute Run in Different Footwear and on Various Slopes
2016 (English)In: Journal of Applied Biomechanics, ISSN 1065-8483, E-ISSN 1543-2688, Vol. 32, no 1, p. 40-49Article in journal (Refereed) Published
Abstract [en]

The effects of footwear and inclination on running biomechanics over short intervals are well documented. Although recognized that exercise duration can impact running biomechanics, it remains unclear how biomechanics change over time when running in minimalist shoes and on slopes. Our aims were to describe these biomechanical changes during a 50-minute run and compare them to those observed in standard shoes. Thirteen trained recreational male runners ran 50 minutes at 65% of their maximal aerobic velocity on a treadmill, once in minimalist shoes and once in standard shoes, 1 week apart in a random order. The 50-minute trial was divided into 5-minute segments of running at 0%, + 5%, and -5% of treadmill incline sequentially. Data were collected using photocells, high-speed video cameras, and plantar-pressure insoles. At 0% incline, runners exhibited reduced leg stiffness and plantar flexion angles at foot strike and lower plantar pressure at the forefoot and toes in minimalist shoes from minute 34 of the protocol onward. However, only reduced plantar pressure at the toes was observed in standard shoes. Overall, similar biomechanical changes with increased exercise time were observed on the uphill and downhill inclines. The results might be due to the unfamiliarity of subjects to running in minimalist shoes.

Keywords
barefoot running, fatigue, kinematics, plantar pressure, inclination
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-27253 (URN)10.1123/jab.2015-0108 (DOI)000368518000006 ()26367201 (PubMedID)2-s2.0-84955288382 (Scopus ID)
Available from: 2016-03-21 Created: 2016-03-17 Last updated: 2017-11-30Bibliographically approved
Hébert-Losier, K., Mourot, L. & Holmberg, H.-C. (2015). Elite and amateur orienteers' running biomechanics on three surfaces at three speeds. Medicine & Science in Sports & Exercise, 47(2), 381-389
Open this publication in new window or tab >>Elite and amateur orienteers' running biomechanics on three surfaces at three speeds
2015 (English)In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 2, p. 381-389Article in journal (Refereed) Published
Abstract [en]

PURPOSE: Orienteering athletes must adapt to running on various surfaces, with biomechanics likely contributing to performance. Here, our aims were to identify the effect of athletic status and of surface on the running biomechanics of orienteers. METHODS: Seven elite and seven amateur male orienteers ran 20 m on road, path, and forest surfaces at maximal, 3.8 m·s, and 85% of maximal speeds. A three-dimensional motion capturing system monitored temporal gait and lower extremity kinematic parameters. Data were analyzed using mixed effects models that considered surface (road-path-forest), group (elite-amateur), and surface-group interaction effects. RESULTS: Forest running at maximal speed was slower and involved longer step and cycle times, greater knee extension at foot strike, smaller peak hip flexion and dorsiflexion during stance, and increased ranges of vertical pelvis motion compared with those observed on the road. Elites specifically exhibited greater hip extension at foot strike, larger dorsiflexion at toe-off, and lower pelvis at foot strike and toe-off, whereas amateurs displayed longer stance, greater plantarflexion at foot strike, and greater knee with lesser ankle motion. At the slowest speed, subjects exhibited greater knee flexion at foot strike, greater dorsiflexion at toe-off, shorter strides, smaller peak dorsiflexion during stance, and greater hip, knee, and vertical pelvis motions on forest than on road surfaces. Elites specifically demonstrated shorter stance, step, and cycle times whereas amateurs did not. CONCLUSIONS: Orienteering athletes adjusted their running biomechanics when off-road, with distinct adaptations observed in elite versus amateur competitors. The vertical pelvis motion was consistently greater when running off-road, coherent with reported increases in energy expenditure. However, our athletes did not exhibit more crouched lower limb postures when sprinting in the forest, indicating alternative responses to off-road running to that previously proposed by "Groucho" running.

Keywords
Athletic Performance, Foot Orienteer, Kinematics, Running Off-Road, Three-Dimensional Motion Analysis
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-24605 (URN)10.1249/MSS.0000000000000413 (DOI)000348100800021 ()2-s2.0-84922018026 (Scopus ID)
Note

CODEN: MSCSB

Available from: 2015-08-28 Created: 2015-03-17 Last updated: 2017-12-04Bibliographically approved
Hébert-Losier, K. & Holmberg, H.-C. (2015). Exercise prescription to prevent injuries during recreational skiing and snowboarding. Paper presented at World Confederation for Physical Therapy Congress 2015, Singapore, 1-4 May 2015. Physiotherapy, 101(Suppl. 1), e552
Open this publication in new window or tab >>Exercise prescription to prevent injuries during recreational skiing and snowboarding
2015 (English)In: Physiotherapy, ISSN 0031-9406, E-ISSN 1873-1465, Vol. 101, no Suppl. 1, p. e552-Article in journal, Meeting abstract (Refereed) Published
Place, publisher, year, edition, pages
Elsevier, 2015
National Category
Physiotherapy
Identifiers
urn:nbn:se:miun:diva-26810 (URN)10.1016/j.physio.2015.03.3366 (DOI)
Conference
World Confederation for Physical Therapy Congress 2015, Singapore, 1-4 May 2015
Available from: 2016-01-04 Created: 2016-01-04 Last updated: 2017-12-01Bibliographically approved
Supej, M., Hebert-Losier, K. & Holmberg, H.-C. (2015). Impact of the Steepness of the Slope on the Biomechanics of World Cup Slalom Skiers. International Journal of Sports Physiology and Performance, 10(3), 361-368
Open this publication in new window or tab >>Impact of the Steepness of the Slope on the Biomechanics of World Cup Slalom Skiers
2015 (English)In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273, Vol. 10, no 3, p. 361-368Article in journal (Refereed) Published
Abstract [en]

Purpose: Numerous environmental factors can affect alpine-ski-racing performance, including the steepness of the slope. However, little research has focused on this factor. Accordingly, the authors' aim was to determine the impact of the steepness of the slope on the biomechanics of World Cup slalom ski racers. Methods: The authors collected 3-dimensional kinematic data during a World Cup race from 10 male slalom skiers throughout turns performed on a relatively flat (19.8 degrees) and steep (25.2 degrees) slope under otherwise similar course conditions. Results: Kinematic data revealed differences between the 2 slopes regarding the turn radii of the skis and center of gravity, velocity, acceleration, and differential specific mechanical energy (all P < .001). Ground-reaction forces (GRFs) also tended toward differences (P = .06). Examining the time-course behaviors of variables during turn cycles indicated that steeper slopes were associated with slower velocities but greater accelerations during turn initiation, narrower turns with peak GRFs concentrated at the midpoint of steering, more pronounced lateral angulations of the knees and hips at the start of steering that later became less pronounced, and overall slower turns that involved deceleration at completion. Consequently, distinct energy-dissipation-patterns were apparent on the 2 slope inclines, with greater pregate and lesser postgate dissipation on the steeper slope. The steepness of the slope also affected the relationships between mechanical skiing variables. Conclusions: The findings suggest that specific considerations during training and preparation would benefit the race performance of slalom skiers on courses involving sections of varying steepness.

Keywords
Alpine skiing, Athletic performance, Kinematics, Kinetics, Winter sports
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-25688 (URN)10.1123/ijspp.2014-0200 (DOI)000352335500014 ()25229249 (PubMedID)2-s2.0-84929027637 (Scopus ID)
Available from: 2015-08-27 Created: 2015-08-18 Last updated: 2017-12-04Bibliographically approved
Hébert-Losier, K., Platt, S. & Hopkins, W. G. (2015). Sources of Variability in Performance Times at the World Orienteering Championships. Medicine & Science in Sports & Exercise, 47(7), 1523-1530
Open this publication in new window or tab >>Sources of Variability in Performance Times at the World Orienteering Championships
2015 (English)In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 7, p. 1523-1530Article in journal (Refereed) Published
Abstract [en]

Purpose An improvement equal to 0.3 of the typical variation in an elite athlete's race-to-race performance estimates the smallest worthwhile enhancement, which has not yet been determined for orienteers. Moreover, much of the research in high-performance orienteering has focused on physical and cognitive aspects, although course characteristics might influence race performance. Analysis of race data provides insights into environmental effects and other aspects of competitive performance. Our aim was to examine such factors in relation to World Orienteering Championships performances. Methods We used mixed linear modelling to analyze finishing times from the three qualification rounds and final round of the sprint, middle-distance, and long-distance disciplines of World Orienteering Championships from 2006 to 2013. Models accounted for race length, distance climbed, number of controls, home advantage, venue identity, round (qualification final), athlete identity, and athlete age. Results Within-athlete variability (coefficient of variation, mean SD) was lower in the final (4.9% +/- 1.4%) than in the qualification (7.3% +/- 2.4%) rounds and provided estimates of smallest worthwhile enhancements of 1.0%-3.5%. The home advantage was clear in most disciplines, with distance climbed particularly impacting sprint performances. Small to very large between-venue differences were apparent. Performance predictability expressed as intraclass correlation coefficients was extremely high within years and was high to very high between years. Age of peak performance ranged from 27 to 31 yr. Conclusions Our results suggest that elite orienteers should focus on training and strategies that enhance performance by at least 1.0%-3.5% for smallest worthwhile enhancement. Moreover, as greater familiarity with the terrain likely mediated the home advantage, foreign athletes would benefit from training in nations hosting the World Orienteering Championships for familiarization.

Keywords
ATHLETIC PERFORMANCE, FOOT ORIENTEER, LINEAR MODELS, STATISTICS, RELIABILITY
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-25659 (URN)10.1249/MSS.0000000000000558 (DOI)000356493300024 ()25373484 (PubMedID)2-s2.0-84942834228 (Scopus ID)
Available from: 2015-08-28 Created: 2015-08-18 Last updated: 2017-12-04Bibliographically approved
Hébert-Losier, K., Supej, M. & Holmberg, H.-C. (2014). Biomechanical Factors Influencing the Performance of Elite Alpine Ski Racers. Sports Medicine, 44(4), 519-533
Open this publication in new window or tab >>Biomechanical Factors Influencing the Performance of Elite Alpine Ski Racers
2014 (English)In: Sports Medicine, ISSN 0112-1642, E-ISSN 1179-2035, Vol. 44, no 4, p. 519-533Article, review/survey (Refereed) Published
Abstract [en]

BackgroundAlpine ski racing is a popular international winter sport that is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of scientific literature focusing on this sport, including topical reviews on physiology, ski-snow friction, and injuries, no review has yet addressed the biomechanics of elite alpine ski racers and which factors influence performance. In World Cup events, winning margins are often mere fractions of a second and biomechanics may well be a determining factor in podium place finishes.

Objective The aim of this paper was to systematically review the scientific literature to identify the biomechanical factors that influence the performance of elite alpine ski racers, with an emphasis on slalom, giant slalom, super-G, and downhill events.

Methods Four electronic databases were searched using relevant medical subject headings and key words, with an additional manual search of reference lists, relevant journals, and key authors in the field. Articles were included if they addressed human biomechanics, elite alpine skiing, and performance. Only original research articles published in peer-reviewed journals and in the English language were reviewed. Articles that focused on skiing disciplines other than the four of primary interest were excluded (e.g., mogul, ski-cross and freestyle skiing). The articles subsequently included for review were quality assessed using a modified version of a validated quality assessment checklist. Data on the study population, design, location, and findings relating biomechanics to performance in alpine ski racers were extracted from each article using a standard data extraction form.

Results A total of 12 articles met the inclusion criteria, were reviewed, and scored an average of 69 ± 13 % (range 40–89 %) upon quality assessment. Five of the studies focused on giant slalom, four on slalom, and three on downhill disciplines, although these latter three articles were also relevant to super-G events. Investigations on speed skiing (i.e., downhill and super-G) primarily examined the effect of aerodynamic drag on performance, whereas the others examined turn characteristics, energetic principles, technical and tactical skills, and individual traits of high-performing skiers. The range of biomechanical factors reported to influence performance included energy dissipation and conservation, aerodynamic drag and frictional forces, ground reaction force, turn radius, and trajectory of the skis and/or centre of mass. The biomechanical differences between turn techniques, inter-dependency of turns, and abilities of individuals were also identified as influential factors in skiing performance. In the case of slalom and giant slalom events, performance could be enhanced by steering the skis in such a manner to reduce the ski-snow friction and thereby energy dissipated. This was accomplished by earlier initiation of turns, longer path length and trajectory, earlier and smoother application of ground reaction forces, and carving (rather than skidding). During speed skiing, minimizing the exposed frontal area and positioning the arms close to the body were shown to reduce the energy loss due to aerodynamic drag and thereby decrease run times. In actual races, a consistently good performance (i.e., fast time) on different sections of the course, terrains, and snow conditions was a characteristic feature of winners during technical events because these skiers could maximize gains from their individual strengths and minimize losses from their respective weaknesses.

Limitations Most of the articles reviewed were limited to investigating a relatively small sample size, which is a usual limitation in research on elite athletes. Of further concern was the low number of females studied, representing less than 4 % of all the subjects examined in the articles reviewed. In addition, although overall run time is the ultimate measure of performance in alpine ski racing, several other measures of instantaneous performance were also employed to compare skiers, including the aerodynamic drag coefficient, velocity, section time, time lost per change in elevation, and mechanical energy behaviours, which makes cross-study inferences problematic. Moreover, most studies examined performance through a limited number of gates (i.e., 2–4 gates), presumably because the most commonly used measurement systems can only capture small volumes on a ski field with a reasonable accuracy for positional data. Whether the biomechanical measures defining high instantaneous performance can be maintained throughout an entire race course remains to be determined for both male and female skiers.

Conclusions Effective alpine skiing performance involves the efficient use of potential energy, the ability to minimize ski-snow friction and aerodynamic drag, maintain high velocities, and choose the optimal trajectory. Individual tactics and techniques should also be considered in both training and competition. To achieve better run times, consistency in performance across numerous sections and varied terrains should be emphasized over excellence in individual sections and specific conditions.

Place, publisher, year, edition, pages
IADIS Press, 2014
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:miun:diva-20921 (URN)10.1007/s40279-013-0132-z (DOI)000333528400008 ()2-s2.0-84897408810 (Scopus ID)
Projects
Swedish Winter Sports Research Centre
Note

Publ online 28 Dec 2013

Available from: 2014-01-01 Created: 2014-01-01 Last updated: 2017-12-06Bibliographically approved
Hébert-Losier, K. & Holmberg, H.-C. (2014). Dynamometric indicators of fatigue from repeated maximal concentric isokinetic plantar-flexion contractions are independent of knee flexion angles and age, but differ for males and females.. Journal of Strength and Conditioning Research, 28(3), 843-855
Open this publication in new window or tab >>Dynamometric indicators of fatigue from repeated maximal concentric isokinetic plantar-flexion contractions are independent of knee flexion angles and age, but differ for males and females.
2014 (English)In: Journal of Strength and Conditioning Research, ISSN 1064-8011, E-ISSN 1533-4287, Vol. 28, no 3, p. 843-855Article in journal (Refereed) Published
Abstract [en]

Sex and age are reported to influence the maximal dynamometric performance of major muscle groups, inclusive of ankle plantar-flexors. Knee flexion (KF) also impacts plantar-flexion function from where stems utilization of 0[degrees] and 45[degrees] of KF for clinical assessment of gastrocnemius and soleus, respectively. The influence of KF, sex and age on dynamometric indicators of plantar-flexion fatigue was examined in 28 males and 28 females recruited in two different age groups (above and below 40 years). Each subject performed 50 maximal concentric isokinetic plantar-flexions at 60 deg[middle dot]s-1 with 0[degrees] and 45[degrees] of KF. Maximal voluntary isometric contractions were determined before and after isokinetic trials; and maximal, minimal and normalized linear slopes of peak power during testing. Main effects of and two-way interactions between KF, sex, age and order of testing were explored using mixed-effect models and stepwise regressions. At 0[degrees] and 45[degrees], the fatigue indicators in younger and older individuals were similar and not influenced by testing order. However, peak isokinetic power and isometric torque declined to greater extents in males than females and, moreover, KF exerted greater impacts on the absolute plantar-flexion performance and maximal-to-minimal reduction in isokinetic power in males. Because KF wielded no pronounced effect on fatigue indicators, this test may perhaps be used over time with no major concern regarding the exact knee angle. Our findings indicate that sex, rather than age, should be considered when interpreting dynamometric indicators of fatigue from repeated maximal concentric isokinetic plantar-flexions, e.g., when establishing normative values or comparing outcomes.

Keywords
triceps surae muscle, fatigability, ankle, endurance, lower extremity, dynamometer
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:miun:diva-20918 (URN)10.1519/JSC.0b013e3182a993a0 (DOI)000332153100031 ()24263655 (PubMedID)2-s2.0-84898042890 (Scopus ID)
Projects
Swedish Winter Sports Research Centre
Note

Publ online nov 2013

Available from: 2014-01-01 Created: 2014-01-01 Last updated: 2017-12-06Bibliographically approved
Mourot, L., Fabre, N., Andersson, E., Willis, S. J., Hébert-Losier, K. & Holmberg, H.-C. (2014). Impact of the initial classic section during a simulated cross-country skiing skiathlon on the cardiopulmonary responses during the subsequent period of skate skiing. Applied Physiology, Nutrition and Metabolism, 39(8), 911-919
Open this publication in new window or tab >>Impact of the initial classic section during a simulated cross-country skiing skiathlon on the cardiopulmonary responses during the subsequent period of skate skiing
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2014 (English)In: Applied Physiology, Nutrition and Metabolism, ISSN 1715-5320, Vol. 39, no 8, p. 911-919Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to assess potential changes in the performance and cardiorespiratory responses of elite cross-country skiers following transition from the classic (CL) to the skating (SK) technique during a simulated skiathlon. Eight elite male skiers performed two 6 km (2 × 3 km) roller-skiing time trials on a treadmill at racing speed: one starting with the classic and switching to the skating technique (CL1-SK2) and another employing the skating technique throughout (SK1-SK2), with continuous monitoring of gas exchanges, heart rates, and kinematics (video). The overall performance times in the CL1-SK2 (21:12 ± 1:24) and SK1-SK2 (20:48 ± 2:00) trials were similar, and during the second section of each performance times and overall cardiopulmonary responses were also comparable. However, in comparison with SK1-SK2, the CL1-SK2 trial involved significantly higher increases in minute ventilation (VE, 89.8 ± 26.8 vs. 106.8 ± 17.6 L·min-1) and oxygen uptake (VO2; 3.1 ± 0.8 vs 3.5 ±0.5 L·min-1) 2 min after the transition as well as longer time constants for VE, VO2, and heart rate during the first 3 min after the transition. This higher cardiopulmonary exertion was associated with ~3% faster cycle rates. In conclusion, overall performance during the 2 time trials did not differ. The similar performance times during the second sections were achieved with comparable mean cardiopulmonary responses. However, the observation that during the initial 3-min post-transition following classic skiing cardiopulmonary responses and cycle rates were slightly higher supports the conclusion that an initial section of classic skiing exerts an impact on performance during a subsequent section of skate skiing.

Keywords
Heart rate, Kinematics, Lower-body, Oxygen pulse, Oxygen uptake, Performance, Skier, Upper-body, Ventilation
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-22631 (URN)10.1139/apnm-2013-0550 (DOI)000341559700007 ()2-s2.0-84905195597 (Scopus ID)
Note

Correspondence Address: Mourot, L.; EA 4660 Culture Sport Health Society and Exercise Performance, Health, Innovation Platform, University of Franche-Comté, 19 rue A Paré, Batiment Socrate - Plateforme EPSI, F-25030 Besancon, France; email: laurent.mourot@univ-fcomte.fr

Available from: 2014-09-22 Created: 2014-08-20 Last updated: 2014-10-13Bibliographically approved
Hébert-Losier, K., Jensen, K. & Holmberg, H.-C. (2014). Jumping and hopping in elite and amateur orienteering athletes and correlations to sprinting and running. International Journal of Sports Physiology and Performance, 9(6), 993-999
Open this publication in new window or tab >>Jumping and hopping in elite and amateur orienteering athletes and correlations to sprinting and running
2014 (English)In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273, Vol. 9, no 6, p. 993-999Article in journal (Refereed) Published
Abstract [en]

PURPOSE:

Jumping and hopping are used to measure lower-body muscle power, stiffness, and stretch-shortening-cycle utilization in sports, with several studies reporting correlations between such measures and sprinting and/or running abilities in athletes. Neither jumping and hopping nor correlations with sprinting and/or running have been examined in orienteering athletes.

METHODS:

The authors investigated squat jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), and hopping performed by 8 elite and 8 amateur male foot-orienteering athletes (29 ± 7 y, 183 ± 5 cm, 73 ± 7 kg) and possible correlations to road, path, and forest running and sprinting performance, as well as running economy, velocity at anaerobic threshold, and peak oxygen uptake (VO(2peak)) from treadmill assessments.

RESULTS:

During SJs and CMJs, elites demonstrated superior relative peak forces, times to peak force, and prestretch augmentation, albeit lower SJ heights and peak powers. Between-groups differences were unclear for CMJ heights, hopping stiffness, and most SLJ parameters. Large pairwise correlations were observed between relative peak and time to peak forces and sprinting velocities; time to peak forces and running velocities; and prestretch augmentation and forest-running velocities. Prestretch augmentation and time to peak forces were moderately correlated to VO(2peak). Correlations between running economy and jumping or hopping were small or trivial.

CONCLUSIONS:

Overall, the elites exhibited superior stretch-shortening-cycle utilization and rapid generation of high relative maximal forces, especially vertically. These functional measures were more closely related to sprinting and/or running abilities, indicating benefits of lower-body training in orienteering.

Keywords
athletic performance, foot orienteering, jump tests, off-road running, stiffness
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-23798 (URN)10.1123/ijspp.2013-0486 (DOI)000344834500016 ()24664965 (PubMedID)2-s2.0-84911925147 (Scopus ID)
Available from: 2014-12-16 Created: 2014-12-16 Last updated: 2017-12-05Bibliographically approved
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