Change search
ReferencesLink to record
Permanent link

Direct link
Physiological and Biomechanical Aspects of Sprint Skiing
Norwegian University of Science and Technology, Faculty of Social Sciences and Technology Management, Department of Human Movement Science.
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Sprint cross-country skiing is a physiologically and technically complex discipline, performed as a time-trial qualification race and three subsequent knock-out heats. The racing time in a single heat is 2-4 min and is comparable to other middle-distance sports. However, sprint skiing is performed in varied terrain at constantly changing intensities using multiple techniques involving the arms and the legs to various degrees. The overall objectives of the current thesis were to examine physiological and biomechanical aspects associated with sprint skiing performance in the skating technique in elite skiers: 1) while treadmill roller skiing in the laboratory (studies I-IV), 2) during sprint competitions on snow (studies IV-V) and 3) for relationships between laboratory characteristics and performance on snow (studies IV-V).

Studies I-III are comparative studies in which physiological characteristics, mechanical efficiency and gross kinematics during treadmill roller skiing were compared between male world-class and national level sprint skiers (studies I-II), and between men and women matched for performance level (study III). Study I showed that maximal aerobic capacity, gross efficiency and high speed capacity differentiated world-class from national level sprint skiers. The study also indicated that low and moderate intensity endurance training and maximal speed training is important in attaining an international level in sprint skiing. Study II demonstrated that world-class sprint skiers had a higher gross efficiency than national level skiers. A general linear relationship between work rate and metabolic rate existed, indicating that gross efficiency at moderate and high work rates provides useful information about crosscountry skiers in standardized conditions during treadmill roller skiing. Furthermore, worldclass skiers used longer cycle lengths and lower cycle rates at a given speed and generated higher maximal speeds. In study III, men showed a 17% higher peak treadmill speed at a short and long incremental test compared to women. These gender differences were slightly greater than findings in comparable endurance sports. The majority of gender differences in performance could be explained by higher maximal oxygen uptakes and lower fat percentages in men. Men and women showed similar gross efficiency. However, women showed higher fractional utilization of maximal oxygen uptake at the anaerobic threshold.

In studies IV-V, elite male skiers were analyzed for speeds, work rates, technique choices and gross kinematics during two sprint time-trial competitions on snow. Furthermore, the skiers were tested for physiological and kinematical characteristics in the laboratory. Study IV analyzed the time-trial of an international sprint competition. The results showed that performance on uphill and flat terrain strongly determined sprint time-trial performance, and that performance in the last half of the race differentiated most between skiers. Estimated work rates on an uphill section of the race were approximately 60% higher than the capacities which the skiers are able to cover aerobically. Peak oxygen uptake, gross efficiency, peak treadmill speed and peak cycle length were strongly related to sprint time-trial performance, particularly to the uphill and flat sections during the last part of the race. Study V analyzed a simulated sprint race by using a high end differential global navigation satellite system with simultaneous tracking of both GPS and GLONASS satellites. This provided an opportunity for more detailed analysis of cross-country skiing. Skiers encompassed a large speed range (2.9–12.9 m·s-1) and multiple transitions between skiing techniques (range: 21–34 transitions). The results demonstrated that performance in the uphill sections had the strongest correlation to sprint performance, and that the faster skiers used the G3 technique to a greater extent than the slower skiers.

Thus, this provides new knowledge on physiological and biomechanical aspects of sprint skating performance, particularly that both the maximal aerobic and peak speed capacities differed between world-class and national level sprint skiers. Furthermore, gross efficiency, while treadmill roller skiing provides relevant information strongly related to sprint performance level. Better skiers also employ longer cycle lengths at the same absolute speeds and at individual peak speeds. The gender differences in performance were slightly larger than expected; however, most of these differences could be explained by a higher maximal oxygen uptake and a lower fat percentage in men. Furthermore, the variations in speeds, work rates and techniques and, especially, speed in uphill and flat terrain are important to the skiers’ total time-trial performance. Better sprint performance is related to more application of the G3 technique and to longer cycle lengths within this technique. Faster skiers showed higher peak oxygen uptake, gross efficiency and high speed capacity. These capacities were specifically correlated to the ability to maintain high speed on uphill and flat terrain throughout a sprint race.

 

Abstract [no]

Sprintlangrenn er ein fysiologisk og biomekanisk kompleks disiplin som blir utført som ein prolog og tre etterfølgjande utslagsløp. Konkurransetidene i kvart enkelt heat er 2-4 min og kan samanliknast med andre mellomdistanseidrettar. Sprintlangrenn blir imidlertid gjennomført i kupert terreng og med varierande arbeidsintensitet og innslag av ulike teknikkar som involverer underkropp og overkropp i ulik grad. Den overordna målsetjinga med denne avhandlinga var å undersøke fysiologiske og biomekaniske aspekt som er assosiert med prestasjonen i sprint skøyting hos elite langrennsløparar: 1) på rulleskitredemølle i laboratoriet (studia I-IV), 2) i sprintkonkurransar på snø (studia IV-V), og 3) for samanhengar mellom laboratorium-karakteristikkar og sprintprestasjonen på snø (studia IV-V).

Studia I-III undersøker forskjellar i fysiologiske karakteristikkar, mekanisk effektivitet og kinematikk mellom mannlege verdsklasse og nasjonal klasse sprintlangrennsløparar (studia III) og mellom mannlege og kvinnelege sprintlangrennsløparar på tilsvarande prestasjonsnivå (studie III). Studie I viser at maksimal aerob kapasitet, mekanisk effektivitet og hurtigheit skil verdsklasse frå nasjonal klasse sprintlangrennsløparar. Studiet indikerer også at låg- og moderat-intensiv uthaldstrening og maksimal hurtigheitstrening er viktig for å nå internasjonalt nivå i sprintlangrenn. Studie II viser at verdsklasse sprintlangrennsløparar har betre mekanisk effektivitet enn løparar på nasjonalt nivå. Studiet viser ein generell lineær samanheng mellom arbeidsratar og energiforbruk og indikerer at målingar av mekanisk effektivitet gir nyttig og valid informasjon om langrennsløparar som blir samanlikna under standardiserte vilkår på rulleskitredemøller. Studiet demonstrerer også at verdsklasse løparane har lengre sykluslengder og lågare syklusfrekvens på ei gitt fart. Studie III viser at menn oppnår 17 % høgre fart enn kvinner både på ein kort og ein lang prestasjonstest med trinnvis aukande fart på rulleskitredemølla. Resultata indikerer at prestasjonsforskjellane mellom kjønna hovudsakleg kan forklarast av høgare maksimalt oksygenopptak og lågare feittprosent hos menn, og at forskjellane er noko større enn det litteraturen viser i andre tilsvarande uthaldsidrettar. Kvinner og menn har lik effektivitet, mens kvinner har høgare prosentvis utnytting av maksimalt oksygenopptak ved anaerob terskel.

I studia IV-V vart fart, arbeidsratar, teknikkval og kinematikk undervegs i sprintkonkurransar undersøkt. Vidare blei samanhengar mellom fysiologiske og kinematiske karakteristikkar i laboratoriet og sprintprestasjonen på snø undersøkt. I studie IV vart prologen i ein internasjonal sprintkonkurranse analysert. Resultata viser at prestasjonen i motbakke og i flatt terreng er sterke forklaringsvariablar for den totale prologprestasjonen. Studiet indikerer også at prestasjonen i siste halvdelen av løypa skil løparane mest. Estimerte arbeidsratar i motbakke indikerer eit totalt arbeid omlag 60% høgare enn det løparane klarer å dekke med aerob energi. Maksimalt oksygenopptak, mekaniske effektivitet, fartskapasitet og sykluslengde var sterkt relatert til sprintprestasjonen, og spesielt til farta i flatt terreng og motbakkar i siste halvdelen av løpet. I studie V vart ein simulert sprintprolog analysert ved bruk av ein høgteknologisk differensial GPS, med svært høg samplingsfrekvens og nøyaktigheit, som hadde samtidig mottak av GPS- og GLONASS-satellittar. Løparane gjennomførte sprintkonkurransen i variert terreng, noko som førte til eit spenn i hastigheiter frå 2.9 til 12.9 m·s-1 og som inkluderte 21–34 teknikkendringar. Motbakkeprestasjonen var høgast korrelert til total prestasjon, og betre skiløparar brukte dobbeldansteknikken i større grad, samanlikna med mindre gode løparar.

Samanfatta så bidreg denne avhandlinga med ny kunnskap om fysiologiske og biomekaniske aspekt av sprintlangrenn i skøyting. Det viser at både maksimal aerob kapasitet og fartskapasitet skil verdsklasse frå nasjonal klasse sprintlangrennsløparar. Det er også vist at målingar av mekanisk effektivitet på rulleskitredemølle gir valid informasjon og er sterkt relatert til prestasjonsnivået til løparane. Dei beste løparane bruker lengre sykluslengder både på same submaksimale fart og på si høgste individuelle fart. Forskjellane mellom mannlege og kvinnelege sprintløparar i prestasjon er noko større enn forventa. Det meste av desse kjønnsforskjellane kan forklarast av at menn har høgare maksimalt oksygenopptak og lågare feittprosent. Undervegs i sprintprologar viser løparane store variasjonar i fart, arbeidsratar og vekslar stadig mellom ulike teknikkar. Spesielt er farta i motbakkar og flatt terreng mot slutten av løpa betydningsfull for prologprestasjonen. Betre prologprestasjon er linka til meir bruk av dobbeldansteknikken og lengre sykluslengder innan denne teknikken. Betre utøvarar har også høgare maksimalt oksygenopptak, effektivitet og fartskapasiet, noko som vart relatert til evna til å oppretthalde høg fart i motbakkar og flatt terreng gjennom eit sprintløp.

Place, publisher, year, edition, pages
NTNU, 2011.
Series
Doctoral theses at NTNU, ISSN 1503-8181 ; 2011:36
Identifiers
URN: urn:nbn:no:ntnu:diva-12139ISBN: 978-82-471-2592-2 (Printed version)ISBN: 978-82-471-2593-9 (Electronic verison)OAI: oai:DiVA.org:ntnu-12139DiVA: diva2:403578
Public defence
2011-02-11, 00:00
Available from: 2011-03-14 Created: 2011-02-28 Last updated: 2011-03-14Bibliographically approved
List of papers
1. The physiology of world-class sprint skiers.
Open this publication in new window or tab >>The physiology of world-class sprint skiers.
2010 (English)In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838Article in journal (Refereed) Epub ahead of print
Abstract [en]

The present study investigated the physiological characteristics of eight world-class (WC) and eight national-class (NC) Norwegian sprint cross country skiers. To measure the physiological response and treadmill performance, the skiers performed a submaximal test, a peak aerobic capacity (VO(2peak) ) test, and a peak treadmill speed (V(peak) ) test in the skating G3 technique. Moreover, the skiers were tested for G3 acceleration outdoors on asphalt and maximal strength in the lab. The standard of sprint skating performance level on snow was determined by International Ski Federation points, and the training distribution was quantified. WC skiers showed 8% higher VO(2peak) and twice as long a VO(2) plateau time at the VO(2peak) test, and a higher gross efficiency at the submaximal test (all P<0.05). Furthermore, WC skiers showed 8% higher V(peak) (P<0.05), but did not differ from NC skiers in acceleration and maximal strength. WC skiers performed more low- and moderate-intensity endurance training and speed training (both P<0.05). The current results show that aerobic capacity, efficiency, and high speed capacity differentiate WC and NC sprint skiers and it is suggested that these variables determine sprint skiing performance.

Place, publisher, year, edition, pages
Wiley, 2010
Identifiers
urn:nbn:no:ntnu:diva-12135 (URN)10.1111/j.1600-0838.2010.01117.x (DOI)20500558 (PubMedID)
Available from: 2011-02-28 Created: 2011-02-28 Last updated: 2011-03-14Bibliographically approved
2. Metabolic rate and gross efficiency at high work rates in world class and national level sprint skiers.
Open this publication in new window or tab >>Metabolic rate and gross efficiency at high work rates in world class and national level sprint skiers.
2010 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 109, no 3, 473-81 p.Article in journal (Refereed) Published
Abstract [en]

The present study investigated metabolic rate (MR) and gross efficiency (GE) at moderate and high work rates, and the relationships to gross kinematics and physical characteristics in elite cross-country skiers. Eight world class (WC) and eight national level (NL) male sprint cross-country skiers performed three 5-min stages using the skating G3 technique, whilst roller skiing on a treadmill. GE was calculated by dividing work rate by MR. Work rate was calculated as the sum of power against gravity and frictional rolling forces. MR was calculated using gas exchange and blood lactate values. Gross kinematics, i.e. cycle length (CL) and cycle rate (CR) were measured by video analysis. Furthermore, the skiers were tested for time to exhaustion (TTE), peak oxygen uptake (VO(2peak)), and maximal speed (V(max)) on the treadmill, and maximal strength in the laboratory. Individual performance level in sprint skating was determined by FIS points. WC skiers did not differ in aerobic MR, but showed lower anaerobic MR and higher GE than NL skiers at a given speed (all P < 0.05). Moreover, WC skiers skated with longer CL and had higher V(max) and TTE (all P < 0.05). In conclusion, the present study shows that WC skiers are more efficient than NL skiers, and it is proposed that this might be due to a better technique and to technique-specific power.

Place, publisher, year, edition, pages
Springer, 2010
Identifiers
urn:nbn:no:ntnu:diva-12136 (URN)10.1007/s00421-010-1372-3 (DOI)20151149 (PubMedID)
Available from: 2011-02-28 Created: 2011-02-28 Last updated: 2011-03-14Bibliographically approved
3. Which physiological and kinematic variables determine gender differences in sprint skiing performance?
Open this publication in new window or tab >>Which physiological and kinematic variables determine gender differences in sprint skiing performance?
(English)Manuscript (preprint) (Other academic)
Identifiers
urn:nbn:no:ntnu:diva-12137 (URN)
Available from: 2011-02-28 Created: 2011-02-28 Last updated: 2011-03-14Bibliographically approved
4. Analysis of a sprint ski race and associated laboratory determinants of world-class performance.
Open this publication in new window or tab >>Analysis of a sprint ski race and associated laboratory determinants of world-class performance.
Show others...
2010 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327Article in journal (Refereed) Epub ahead of print
Abstract [en]

This investigation was designed to analyze the time-trial (STT) in an international cross-country skiing sprint skating competition for (1) overall STT performance and relative contributions of time spent in different sections of terrain, (2) work rate and kinematics on uphill terrain, and (3) relationships to physiological and kinematic parameters while treadmill roller ski skating. Total time and times in nine different sections of terrain by 12 world-class male sprint skiers were determined, along with work rate and kinematics for one specific uphill section. In addition, peak oxygen uptake (VO(2peak)), gross efficiency (GE), peak speed (V(peak)), and kinematics in skating were measured. Times on the last two uphill and two final flat sections were correlated to overall STT performance (r = ~-0.80, P < 0.001). For the selected uphill section, speed was correlated to cycle length (r = -0.75, P < 0.01) and the estimated work rate was approximately 160% of peak aerobic power. VO(2peak), GE, V(peak), and peak cycle length were all correlated to STT performance (r = ~-0.85, P < 0.001). More specifically, VO(2peak) and GE were correlated to the last two uphill and two final flat section times, whereas V(peak) and peak cycle length were correlated to times in all uphill, flat, and curved sections except for the initial section (r = ~-0.80, P < 0.01). Performances on uphill and flat terrain in the latter part were the most significant determinants of overall STT performance. Peak oxygen uptake, efficiency, peak speed, and peak cycle length were strongly correlated to overall STT performance, as well as to performance in different sections of the race.

Place, publisher, year, edition, pages
Springer, 2010
Identifiers
urn:nbn:no:ntnu:diva-12133 (URN)10.1007/s00421-010-1719-9 (DOI)21079989 (PubMedID)
Available from: 2011-02-28 Created: 2011-02-28 Last updated: 2011-03-14Bibliographically approved
5. Analysis of sprint cross-country skiing using a differential global navigation satellite system.
Open this publication in new window or tab >>Analysis of sprint cross-country skiing using a differential global navigation satellite system.
Show others...
2010 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 110, no 3, 585-95 p.Article in journal (Refereed) Published
Abstract [en]

The purpose was to examine skiing velocities, gear choice (G2-7) and cycle rates during a skating sprint time trial (STT) and their relationships to performance, as well as to examine relationships between aerobic power, body composition and maximal skiing velocity versus STT performance. Nine male elite cross-country skiers performed three tests on snow: (1) Maximum velocity test (V (max)) performed using G3 skating, (2) V (max) test performed using double poling (DP) technique and (3) a STT over 1,425 m. Additional measurements of VO(2max) during roller skiing and body composition using iDXA were made. Differential global navigation satellite system data were used for position and velocity and synchronized with video during STT. The STT encompassed a large velocity range (2.9-12.9 m s(-1)) and multiple transitions (21-34) between skiing gears. Skiing velocity in the uphill sections was related to gear selection between G2 and G3. STT performance was most strongly correlated to uphill time (r = 0.92, P < 0.05), the percentage use of G2 (r = -0.72, P < 0.05), and DP V (max) (r = -0.71, P < 0.05). The velocity decrease in the uphills from lap 1 to lap 2 was correlated with VO(2max) (r = -0.78, P < 0.05). V (max) in DP and G3 were related to percent of racing time using G3. In conclusion, the sprint skiing performance was mainly related to uphill performance, greater use of the G3 technique, and higher DP and G3 maximum velocities. Additionally, VO(2max) was related to the ability to maintain racing velocity in the uphills and lean body mass was related to starting velocity and DP maximal speed.

Place, publisher, year, edition, pages
Springer, 2010
Identifiers
urn:nbn:no:ntnu:diva-12134 (URN)10.1007/s00421-010-1535-2 (DOI)20571822 (PubMedID)
Available from: 2011-02-28 Created: 2011-02-28 Last updated: 2011-03-14Bibliographically approved

Open Access in DiVA

fulltext(4029 kB)2354 downloads
File information
File name FULLTEXT02.pdfFile size 4029 kBChecksum SHA-512
9872a7b9c6ec18f2d37dcb6e8fec84b520e1d12c3321f4db8317ec59413090e91cb7bc0683315b8c0be19aa72ced1d87f16f036b3520e893e5b0404a9c1ccaae
Type fulltextMimetype application/pdf

By organisation
Department of Human Movement Science

Search outside of DiVA

GoogleGoogle Scholar
Total: 2354 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 391 hits
ReferencesLink to record
Permanent link

Direct link