Mid Sweden University

Three dominant techniques are used for downhill turning in cross-country skiing. In this study, kinematic, kinetic, and temporal characteristics of these techniques are described and related to skier strength and power. Twelve elite female cross-country skiers performed six consecutive turns of standardized geometry while being monitored by a Global Navigation Satellite System. Overall time was used as an indicator of performance. Skiing and turning parameters were determined from skier trajectories; the proportional use of each technique was determined from video analysis. Leg strength and power were determined by isometric squats and countermovement jumps on a force plate. Snow plowing, parallel skidding, and step turning were utilized for all turns. Faster skiers employed less snow plowing and more step turning, more rapid deceleration and earlier initiation of step turning at higher speed (r = 0.80–0.93; all P < 0.01). Better performance was significantly correlated to higher mean speed and shorter trajectory (r

= 0.99/0.65; both P < 0.05) and to countermovement jump characteristics of peak force, time to peak force, and rate of force development (r  = -0.71/0.78/-0.83; all P < 0.05). In conclusion, faster skiers used step turning to a greater extent and exhibited higher maximal leg power, which enabled them to combine high speeds with shorter trajectories during turns.

The present study investigated the physiological characteristics of eight world class (WC) and eight national class (NC) Norwegian sprint cross-country skiers. To measure 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 FIS points, and the training distribution was quantified. WC skiers showed 8%higher VO_2peak and twice as long VO₂ plateau time at the VO_2peak test, and higher gross efficiency (GE) 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 indicate that aerobic capacity, efficiency and high speed capacity differentiate WC and NC sprint skiers and are strong determinants of sprint performance.

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 (Vmax) performed using G3 skating, (2) Vmax test performed using double poling (DP) technique and (3) a STT over 1,425 m. Additional measurements of VO2max 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 Vmax (r = -0.71, P < 0.05). The velocity decrease in the uphills from lap 1 to lap 2 was correlated with VO2max (r = -0.78, P < 0.05). Vmax 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, VO2max 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.

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. Metabolic rate 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.

Idrettsutøvere, mosjonister og pasienter trener mye med fysioterapeuter som sentrale støttespillere. Hensikten med denne fagkronikken er å gi en nyansert tilnærming til trening som metode. Trening forstås som en veksling mellom spesifikk Artikkelens eksempel er fra utholdenhetsstrening. Følgende faktorer presenteres og diskuteres opp mot å forbedre prestasjonsevnen: 1) Prestasjonsbegrensende faktorer som grunnlag for prioriteringsområder. 2) Innholdet i treningsopplegget. 3) Praktisk gjennomføring av treningen basert på individuelle egenskaper og livsstil. Artikkelen bruker analogien om å legge et puslespill, et spill med flere biter fra de tre nevnte faktorene som innvirker på å forbedre prestasjon. Eksempler på plan for løsninger er fire praktiske treningsprogrammer for en toppidrettsutøver og en mosjonist. Det vil si, en ukeplan og en dagsplan for hver av dem. I sum er oppgaven til fysioterapeuten og treningsopplegget å bidra til å klargjøre prioriteringene og arbeidsoppgavene for utøvere og pasienter. Opplegget baseres på vitenskaplige prinsipper, mens gjennomføringen er selve kunsten. aktivitetsbelastning og hvile av de funksjonene i kroppen som skal tilpasse seg og oppnå forbedret funksjon over tid. Spesifikk betyr at treningen rettes direkte mot de faktorene som begrenser prestasjonen eller funksjonen.

Top athletes, exercisers and patients do a lot of training with physiotherapists as key supporters. The aim of this debate article is to give a nuanced approach to training as a method. Training is here seen as an alternation between specific activity loading and rest of the bodily functions that need to be adjusted, and to improve function over time. Specific means that the training is aimed directly at the factors limiting the performance or function. The example used in this article is endurance training. The following factors are presented and discussed towards improving performance: 1) Performance restricting factors as a base for priorities. 2) The content of the training program. 3) The practical execution of training, based on individual characteristics and lifestyle. The article uses the analogy of solving a jigsaw-puzzle, a puzzle including several bits from the three mentioned factors for improving performance. Examples of plans for solving puzzles are four practical training schedules for a top athlete and an exerciser. That is, one week schedule and one day schedule for both of them. In sum, the task of the physiotherapist and the training program is to assist in clarifying priorities and tasks for athletes and patients. The program is based on scientific principles, while it’s execution is the main challenge.

Målsetningen med denne artikkelen er å belyse ulike faktorer som påvirker utholdenhetsprestasjonen, samt presentere treningsmetoder for å utvikle prestasjonen videre. Vi mener at en bedret forståelse for hvordan treningen spesifikt påvirker de ulike faktorene, øker forutsetningene for å legge opp treningen optimalt.