| 1. |
- Lankinen, Maria A., et al.
(författare)
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Dietary carbohydrate modification alters serum metabolic profiles in individuals with the metabolic syndrome
- 2010
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Ingår i: NMCD. Nutrition Metabolism and Cardiovascular Diseases. - : Elsevier. - 0939-4753 .- 1590-3729. ; 20:4, s. 249-57
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Whole-grain cereals and diets with a low glycemic index may protect against the development of type 2 diabetes and heart disease, but the mechanisms are poorly understood. We studied the effect of carbohydrate modification on serum metabolic profiles, including lipids and branched chain amino acids, and dependencies between these and specific gene expression pathways in adipose tissue.METHODS AND RESULTS: Twenty subjects with metabolic syndrome were selected from the larger FUNGENUT study population, randomized either to a diet high in oat and wheat bread and potato (OWP) or rye bread and pasta (RP). Serum metabolomics analyses were performed using ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry (UPLC/MS), gas chromatography (GC) and UPLC. In the OWP group multiple proinflammatory lysophosphatidylcholines increased, while in the RP group docosahexaenoic acid (DHA 22:6n-3) increased and isoleucine decreased. mRNA expression of stress reactions- and adipose tissue differentiation-related genes were up-regulated in adipose tissue in the OWP group. In the RP group, however, pathways related to stress reactions and insulin signaling and energy metabolism were down-regulated. The lipid profiles had the strongest association with the changes in the adipose tissue differentiation pathway when using the elastic net regression model of the lipidomic profiles on selected pathways.CONCLUSION: Our results suggest that the dietary carbohydrate modification alters the serum metabolic profile, especially in lysoPC species, and may, thus, contribute to proinflammatory processes which in turn promote adverse changes in insulin and glucose metabolism.
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| 2. |
- Ainegren, Mats, et al.
(författare)
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Skiing economy and efficiency in recreational and elite cross-country skiers
- 2013
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Ingår i: Journal of Strength and Conditioning Research. - 1064-8011 .- 1533-4287. ; 27:5, s. 1239-1252
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Ainegren, Mats, et al.
(författare)
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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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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 24:2, s. 301-310
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Jonsson Kårström, Malin, et al.
(författare)
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Kinematical Effects of Rifle Carriage on Roller-Skiing in Well-Trained Female and Male Biathletes
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Purpose This study aimed to investigate how rifle carriage and skiing speed during biathlon roller-skiing affect range of motion (ROM) in joint angles and equipment (skis and poles), the vertical distance between shoulders and treadmill (vertdist), as well as possible sex differences associated with rifle carriage. Methods Fourteen biathletes (6 women, 8 men) roller-skied on a treadmill at submaximal and simulated race speeds, with (WR) and without (NR) a rifle, using gears 3 and 2. Kinematical data for the whole body, poles, roller-skis, rifle and treadmill were monitored using a 3D motion capture system. Movements determined as flexion/extension (x), abduction/adduction (y) and/or internal/external rotation (z) were analyzed for the hip, shoulder, thorax, knee, ankle, elbow, poles and roller-skis. ROM (the difference between maximal and minimal angles) in joints and equipment, and vertdist were analyzed over six skiing cycles during each condition (WR and NR) and speed. Results The maximal vertdist was lower for WR compared to NR (gear 3: 1.53±0.06 vs 1.54±0.06 m; gear 2: 1.49±0.06 vs 1.51±0.06 m; both p<0.001). ROM in the upper body was altered when roller-skiing WR (movements decreased in thorax and shoulder (x) and increased in elbow (only gear 3) (x), thorax (only gear 2) and shoulder (y) and (z); all p><0.05) and increased with speed, without differences between sexes (p>0.05). Conclusion Since rifle carriage and speed appear to affect the kinematics of rollerskiing, coaches and biathletes are advised to perform skiing technique training under competition-like conditions (i.e., at race speeds while carrying the rifle).
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| 5. |
- Jonsson Kårström, Malin, et al.
(författare)
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Kinematical effects of rifle carriage on roller skiing in well-trained female and male biathletes
- 2023
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 33:4, s. 444-454
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This study aimed to investigate how rifle carriage and skiing speed during biathlon roller skiing affect range of motion (ROM) in joint angles and equipment (skis and poles), the vertical distance between shoulders and treadmill (vertdist), as well as possible sex differences associated with rifle carriage. Methods: Fourteen biathletes (6 women, 8 men) roller-skied on a treadmill at submaximal and simulated race speeds, with (WR) and without (NR) a rifle, using gears 3 and 2. Kinematical data for the whole body, poles, roller-skis, rifle, and treadmill were monitored using a 3D motion capture system. Movements determined as flexion/extension (x), abduction/adduction (y), and/or internal/external rotation (z) were analyzed for the hip, shoulder, thorax, knee, ankle, elbow, poles, and roller skis. ROM (the difference between maximal and minimal angles) in joints and equipment, and vertdist were analyzed over six skiing cycles during each condition (WR and NR) and speed. Results: The maximal vertdist was lower for WR compared with NR (gear 3: 1.53 ± 0.06 vs 1.54 ± 0.06 m; gear 2: 1.49 ± 0.06 vs 1.51 ± 0.06 m; both p < 0.001). ROM in the upper body was altered when roller skiing WR (movements decreased in thorax and shoulder (x) and increased in elbow (only gear 3) (x), thorax (only gear 2), and shoulder (y) and (z); all p < 0.05) and increased with speed, without differences between sexes (p > 0.05). Conclusion: Since rifle carriage and speed appear to affect the kinematics of roller skiing, coaches, and biathletes are advised to perform skiing technique training under competition-like conditions (i.e., at race speeds while carrying the rifle).
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| 6. |
- Karlsson, Øyvind, 1989-, et al.
(författare)
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Training and illness characteristics of crosscountry skiers transitioning from junior to senior level
- 2021
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:5 May
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Tidskriftsartikel (refereegranskat)abstract
- Objective This study aimed to describe the endurance training and incidence of illnesses reported by a group of well-trained cross-country (XC) skiers throughout their transition from junior to senior level. Methods Changes in self-reported training and performance, from 31 well-trained XC skiers, were analyzed from the start of the season they turned 16 y until the end of the season they turned 22 y, using linear mixed-effects models. Differences in the incidence of self-reported illness episodes were analyzed using incidence rate ratios, and the relationships between selfreported illness and training volumes were analyzed using linear mixed-effects models in a sub-group of 23 of the skiers. Results In total, 145 seasons of training data (including 85,846 h of endurance training) and 109 person- years of illness data (including 380 self-reported illness episodes) were analyzed. The athletes progressively increased their annual endurance training volume from age 16 to 22 y in a linear fashion, from ~ 470 to 730 h. Low- and high-intensity training volumes increased by 51.4 ± 2.4 h·y-1 (p < .001) and 4.9 ± 0.6 h·y-1 (p < .001), respectively. Sport-specific and non-specific training increased by 50.0 ± 2.2 h·y-1 (p < .001) and 4.6 ± 2.0 h·y-1 (p < .001), respectively. The athletes reported a median (range) of 3 (0-8) illness episodes and 17 (0- 80) days of illness per year, and there was an inverse relationship between self-reported illness days and annual training volume (-0.046 ± 0.013 d?h-1; p < .001). Conclusions This group of well-trained XC skiers increased their endurance training volume in a linear fashion by ~ 55 h annually. This was primarily achieved through an increase in low-intensity and sport-specific training. Furthermore, higher training volumes were associated with a lower number of self-reported illness days.
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| 7. |
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| 8. |
- Köykkä, Miika, et al.
(författare)
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Rifle and aiming point accelerations do not differ between the most and least accurate shots in biathlon shooting within an athlete
- 2023
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Ingår i: Biomedical Human Kinetics. - : Walter de Gruyter GmbH. - 2080-2234. ; 15:1, s. 139-147
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Tidskriftsartikel (refereegranskat)abstract
- Study aim: As studies from shooting disciplines other than biathlon have observed associations between weapon accelerations and shooting performance, this study investigated whether accelerations of the rifle stock and aiming point (the point on the target where the rifle is aimed at) are associated with shooting performance, and differences in rifle and aiming point accelerations between the most and least accurate shots. Further, associations between rifle and aiming point accelerations were studied.Materials and methods: Shooting performance (Hit(Dist), hit point distance from the center of the target) along with rifle and aiming point accelerations were measured from nine biathletes who performed 6x5 biathlon prone and standing shots.Results: In the prone posture, rifle or aiming point accelerations were neither associated with shooting performance nor with each other. In the standing posture, vertical rifle accelerations right before triggering were negatively associated with Hit(Dist) (r = -0.70, p < 0.05), whereas aiming point accelerations were not associated with Hit(Dist). Horizontal rifle accelerations were positively associated with aiming point accelerations in standing (r = 0.74, p = 0.024), whereas vertical or resultant rifle accelerations did not demonstrate associations with aiming point accelerations. In both postures, rifle accelerations were of the same magnitude in the most and least accurate shots.Conclusion: Rifle and aiming point accelerations provide limited description of the technical level in biathlon shooting. Moreover, rifle accelerations alone do not appear to provide sufficient information to deduce the aiming point movements. Angular movement would likely be required for aiming point movement estimation.
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| 9. |
- Laaksonen, Marko, et al.
(författare)
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Effects of exhaustive stretch-shortening cycle exercise on muscle blood flow during exercise
- 2006
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 186:4, s. 261-270
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Aim: The influence of exhaustive stretch-shortening cycle exercise (SSC) on skeletal muscle blood flow (BF) during exercise is currently unknown. Methods: Quadriceps femoris (QF) BF was measured in eight healthy men using positron emission tomography before and 3 days after exhaustive SSC exercise. The SSC protocol consisted of maximal and submaximal drop jumps with one leg. Needle biopsies of the vastus lateralis muscles were taken immediately and 2 days after SSC for muscle endothelial nitric oxide synthase (eNOS) and interleukin-1-beta (IL-1beta) mRNA level determinations. Results: All subjects reported subjective muscle soreness after SSC (P < 0.001), which was well in line with a decrease in maximal isometric contraction force (MVC) and increase in serum creatine kinase activity (CK) (P = 0.018). After SSC muscle BF was 25% higher in entire QF (P = 0.043) and in its deep and superficial muscle regions, whereas oxygen uptake remained unchanged (P = 0.893). Muscle biopsies revealed increased IL-1beta (30 min: 152 +/- 75%, P = 0.012 and 2 days: 108 +/- 203%, P = 0.036) but decreased or unchanged eNOS (30 min; -21 +/- 57%, P = 0.050 and 2 days: +101 +/- 204%, P = 0.779) mRNA levels after SSC. Conclusion: It was concluded that fatiguing SSC exercise induces increased muscle BF during exercise, which is likely to be associated with pro-inflammatory processes in the exercised muscle.
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| 10. |
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