| 1. |
- Ainegren, Mats, 1963-, et al.
(author)
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A portable roller ski rolling resistance measurement system
- 2013
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In: The Impact of Technology on Sport V. - : Elsevier. ; , s. 79-83
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Conference paper (peer-reviewed)abstract
- Roller skis are used by cross-country skiers, biathletes and ski-orienteers for their snow-free training and in roller ski competitions. Additionally, much of the current sports research into the physiology and biomechanics of crosscountry skiing is conducted indoors on treadmills using roller skis. For elite athletes, the differences in performance are quite small, thus emphasising the importance of knowing the roller skis' rolling resistance coefficient, especially in connection to research and roller ski competitions. The purpose of this study was to develop a roller ski rolling resistance measurement system (P-RRMS) that is portable and therefore useful in different contexts and locations. The P-RRMS was designed as a small treadmill, equipped with roller ski stabilizing lateral supports and a screwed bar for applying different vertical loads on the roller ski. The design uses only one force sensor, with possible measurements of three directions of force and torque around three axes. The weight of the P-RRMS is 100 kg and it is equipped with wheels to facilitate transportation.
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| 2. |
- Ainegren, Mats, et al.
(author)
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An experimental study to compare the grip of classical style roller skis with on-snow skiing
- 2013
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In: Sports Engineering. - : Springer Science and Business Media LLC. - 1369-7072 .- 1460-2687. ; 16:2, s. 115-122
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Journal article (peer-reviewed)abstract
- Cross-country skiers use roller skis for their snow-free training with the aim of imitating skiing on snow. Also, exercise laboratories evaluate the biomechanics and physiology of cross-country skiing using roller skis on a treadmill. The roller skis on the market that are constructed for use in the classical style are equipped with a front and a back wheel, one of which has a ratchet to enable it to grip the surface when diagonal striding and kick double poling (static friction). The aim of this study was to investigate static friction coefficients (μS) of ratcheted wheel roller skis, and compare the results to the μS reported from skiing on snow with grip-waxed cross-country skis. Also, a new type of roller ski with a camber and adjustable grip function was evaluated. The results showed that ratcheted wheel roller skis, on a treadmill rubber mat and on dry and wet asphalt surfaces, reached μS values that were five to eight times greater than the values reported from on-snow skiing with grip-waxed cross-country skis. For the roller skis with a camber and adjustable grip function, the μs could be varied from no grip at all up to the level of the tested ratcheted wheel roller skis.
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| 3. |
- Ainegren, Mats, et al.
(author)
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Classical style constructed roller skis and grip functionality
- 2011
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In: Procedia Engineering. - : Elsevier. ; , s. 4-9
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Conference paper (peer-reviewed)abstract
- Roller skis are used by cross-country skiers for snow-free training, with the aim of imitating skiing on snow. The roller skis on the market that are constructed for use in the classical style are equipped with a front and a back wheel, one of which has a ratchet to enable it to grip the surface when diagonal striding and kick double poling.A new type of roller ski was constructed with a function which makes it necessary to use the same kick technique as that used on snow, i.e. the ski has a camber that must be pushed down to obtain grip. Its stiffness can be adjusted based on factors that influence grip, i.e. the skier’s bodyweight and technical skiing skills.Thus, our aim was to make comparative measurements as regards grip between ratcheted roller skis and the roller ski with a camber and compare with previous published results for grip waxed skis during cross-country skiing on snow. The measurements were carried out using specially developed equipment, with a bottom plate and an overlying rubber mat of the same type as used on many treadmills and a function for applying different loads and generating traction on the back of the roller ski.
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| 4. |
- Ainegren, Mats, 1963-, et al.
(author)
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Roller ski rolling resistance and its effects on elite athletes’ performance
- 2009
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In: Sports Engineering. - Paris : Springer. - 1369-7072 .- 1460-2687. - 9782287990564 - 9782287990557 ; 11:3, s. 143-157
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Journal article (peer-reviewed)abstract
- Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes, the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study, the roller skis’ rolling resistance was measured on the ski-treadmill’s surface using a roller ski rolling resistance measurement system specially produced for this purpose. The study investigated the influence of significant changes in rolling resistance on physiological variables. The results showed that during submaximal exercise, power, oxygen uptake, heart rate and blood lactate were significantly changed by different rolling resistances, while there were no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed by different rolling resistances and this occurred without significant changes in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion were insignificant or small.
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| 5. |
- Ainegren, Mats, 1963-, et al.
(author)
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Roller ski rolling resistance and its effects on elite athletes’ performance
- 2008
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In: ENGINEERING OF SPORT 7, VOL 2. - 9782287094125 ; , s. 393-400
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Conference paper (peer-reviewed)abstract
- Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study the roller skis’ rolling resistance has been measured using equipment on the ski-treadmill. The study investigates the influence of significant changes in rolling resistance on physiological variables. The results show that during submaximal exercise, heart rate, blood lactate, power and oxygen uptake are significantly changed by different rolling resistances, while there are no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests show that time to exhaustion is significantly changed by different rolling resistances and this occurred without significant changes in maximal oxygen uptake and heart rate, and the influence on maximal power and ratings of perceived exertion were insignificant or small.
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| 6. |
- Ainegren, Mats, 1963-, et al.
(author)
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Rolling resistance for treadmill roller skiing
- 2008
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In: Sports Engineering. - : Springer. - 1369-7072 .- 1460-2687. ; 11:1, s. 23-29
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Journal article (peer-reviewed)abstract
- Modern treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance under laboratory conditions using classical and freestyle techniques on roller skis. The differences in performance between tests are quite small for elite athletes, and it is therefore of great importance to control the rolling resistance of the roller skis. Otherwise different physiological tests cannot be accurately compared.This study shows that during a warm-up period of 30 minutes the coefficient of rolling resistance (µR) decreases to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively.Simultaneous measurements of temperature and µR shows that stabilized rolling resistance corresponds to a certain running temperature for a given normal force on the roller ski.Tests were also performed on the influence on µR of normal force, velocity and inclination. Normal forces produced significant influence on µR , while different velocities and inclinations of the treadmill only resulted in small changes in µR.
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| 7. |
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| 8. |
- Ainegren, Mats, et al.
(author)
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Skiing economy and efficiency in recreational and elite cross-country skiers
- 2013
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In: Journal of Strength and Conditioning Research. - 1064-8011 .- 1533-4287. ; 27:5, s. 1239-1252
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Journal article (peer-reviewed)abstract
- The purpose of this study was to investigate and compare skiing economy and gross efficiency in cross-country skiers of different performance levels, ages and genders; male recreational skiers and elite senior and junior cross-country skiers of both genders. The skiers performed tests involving roller skiing on a treadmill using the gear 3 and diagonal stride techniques. The elite crosscountry skiers were found to have better skiing economy and higher gross efficiency (5-18%) compared with the recreational skiers (p < 0.05) and the senior elite had better economy and higher efficiency (4-5%) than their junior counterparts (p < 0.05), whereas no differences could be found between the genders. Also, large ranges in economy and gross efficiency were found in all groups. It was concluded that, in addition to v̇O2peak, skiing economy and gross efficiency have a great influence on the differences in performance times between recreational and junior and senior elite cross-country skiers, as well as between individual skiers within the different categories. Thus, we recommend crosscountry skiers at all performance levels to test not only v̇O2peak, but also skiing economy and efficiency.
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| 9. |
- Ainegren, Mats, et al.
(author)
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The influence of grip on oxygen consumption and leg forces when using classical style roller skis
- 2014
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In: Scandinavian Journal of Medicine and Science in Sports. - : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 24:2, s. 301-310
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Journal article (peer-reviewed)abstract
- The purpose of this study was to investigate the influence of classical style roller skis' grip (static friction coefficients, μ S) on cross-country skiers' oxygen consumption and leg forces during treadmill roller skiing, when using the diagonal stride and kick double poling techniques. The study used ratcheted wheel roller skis from the open market and a uniquely designed roller ski with an adjustable camber and grip function. The results showed significantly (P≤0.05) higher oxygen consumption (∼14%), heart rate (∼7%), and lower propulsive forces from the legs during submaximal exercise and a shorter time to exhaustion (∼30%) in incremental maximal tests when using roller skis with a μ S similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a similar, higher μ S. Thus, we concluded that oxygen consumption (skiing economy), propulsive leg forces, and performance time are highly changed for the worse when using roller skis with a lower μ S, such as for on-snow skiing with grip-waxed cross-country skis, in comparison to ratcheted wheel roller skis with several times higher μ S.
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| 10. |
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