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- Fransson, Dan, 1980, et al.
(author)
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Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game
- 2018
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In: Journal of Human Kinetics. - : Walter de Gruyter GmbH. - 1640-5544 .- 1899-7562. ; 61, s. 85-97
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Journal article (peer-reviewed)abstract
- We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12) participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement (p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip abductors (6 ± 1%) demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery.
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- Fransson, Dan, 1980, et al.
(author)
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Skeletal muscle and performance adaptations to high-intensity training in elite male soccer players : speed endurance runs versus small-sided game training
- 2018
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In: European Journal of Applied Physiology. - : Springer. - 1439-6319 .- 1439-6327. ; 118:1, s. 111-121
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Journal article (peer-reviewed)abstract
- To examine the skeletal muscle and performance responses across two different exercise training modalities which are highly applied in soccer training. Using an RCT design, 39 well-trained male soccer players were randomized into either a speed endurance training (SET; n = 21) or a small-sided game group (SSG; n = 18). Over 4 weeks, thrice weekly, SET performed 6-10 x 30-s all-out runs with 3-min recovery, while SSG completed 2 x 7-9-min small-sided games with 2-min recovery. Muscle biopsies were obtained from m. vastus lateralis pre and post intervention and were subsequently analysed for metabolic enzyme activity and muscle protein expression. Moreover, the Yo-Yo Intermittent Recovery level 2 test (Yo-Yo IR2) was performed. Muscle CS maximal activity increased (P < 0.05) by 18% in SET only, demonstrating larger (P < 0.05) improvement than SSG, while HAD activity increased (P < 0.05) by 24% in both groups. Na+-K+ ATPase alpha(1) subunit protein expression increased (P < 0.05) in SET and SSG (19 and 37%, respectively), while MCT4 protein expression rose (P < 0.05) by 30 and 61% in SET and SSG, respectively. SOD2 protein expression increased (P < 0.05) by 28 and 37% in SET and SSG, respectively, while GLUT-4 protein expression increased (P < 0.05) by 40% in SSG only. Finally, SET displayed 39% greater improvement (P < 0.05) in Yo-Yo IR2 performance than SSG. Speed endurance training improved muscle oxidative capacity and exercise performance more pronouncedly than small-sided game training, but comparable responses were in muscle ion transporters and antioxidative capacity in well-trained male soccer players.
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- Lignell, Erik, et al.
(author)
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Analysis of high-intensity skating in top-class ice-hockey match-play in relation to training status and muscle damage.
- 2018
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In: Journal of Strength and Conditioning Research. - 1064-8011. ; 32:5, s. 1303-1310
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Journal article (peer-reviewed)abstract
- Lignell, E, Fransson, D, Krustrup, P, and Mohr, M. Analysis of high-intensity skating in top-class ice hockey match-play in relation to training status and muscle damage. J Strength Cond Res 32(5): 1303-1310, 2018-We examined high-intensity activities in a top-class ice-hockey game and the effect of training status. Male ice-hockey players (n = 36) from the National Hockey League participated. Match analysis was performed during a game and physical capacity was assessed by a submaximal Yo-Yo Intermittent Recovery Ice-hockey test, level 1 (YYIR1-IHSUB). Venous blood samples were collected 24-hour post-game to determine markers of muscle damage. Players performed 119 ± 8 and 31 ± 3 m·min of high intensity and sprint skating, respectively, during a game. Total distance covered was 4,606 ± 219 m (2,260-6,749 m), of which high-intensity distance was 2042 ± 97 m (757-3,026 m). Sprint-skating speed was 5-8% higher (p ≤ 0.05) in periods 1 and 2 vs. period 3 and overtime. Defensemen (D) covered 29% more (p ≤ 0.05) skating in total than forwards (F) and were on the ice 47% longer. However, F performed 54% more (p ≤ 0.05) high-intensity skating per minute than defensemen. Plasma creatine kinase (CK) was 338 ± 45 (78-757) U·L 24-hour post-game. Heart rate loading during YYIR1-IHSUB correlated inversely (p ≤ 0.05) to the frequency of high-intensity skating bouts (r = -0.55) and V[Combining Dot Above]O2max (r = -0.85) and positively to post-game CK (r = 0.49; p ≤ 0.05). In conclusion, ice hockey is a multiple-sprint sport that provokes fatigue in the latter half of a game. Forwards perform more intense skating than defensemen. Moreover, high-intensity game activities during top-class ice hockey are correlated with cardiovascular loading during a submaximal skating test. Taken together, training of elite ice-hockey players should improve the ability for repeated high-intensity skating, and testing should include the YYIR1-IHSUB test as an indicator for ice-hockey-specific physical match performance.
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- Redfors, Björn, et al.
(author)
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Prognosis is similar for patients who undergo primary PCI during regular-hours and off-hours: A report from SCAAR.
- 2018
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In: Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions. - : Wiley. - 1522-726X. ; 91:7, s. 1240-1249
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Journal article (peer-reviewed)abstract
- Timely percutaneous coronary intervention (PCI) improves prognosis in ST-elevation myocardial infarction (STEMI). However, recent reports indicate that patients with STEMI who present during non-regular working hours (off-hours) have a worse prognosis. The aim of this study was to compare outcome between patients with STEMI who underwent primary PCI during off-hours and regular hours.We retrieved data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) for all patients who underwent primary PCI in Region Västra Götaland due to STEMI between January 2004 and May 2013. We modeled unadjusted and adjusted Cox proportional-hazards regression and logistic regression models for the outcomes death, cardiogenic shock, stent thrombosis and in-stent restenosis. A propensity score-adjusted Cox proportional-hazards model, which adjusted for traditional cardiovascular risk factors was predefined as the primary statistical model. Death at any time during the study period was pre-specified as primary end-point.During the study period 4.611 (65%) patients underwent primary PCI due to STEMI during off-hours and 2,525 (35%) during regular hours. The risk of dying was similar among the groups for the primary endpoint death at any time during the study period (HR 1.00, 95% CI 0.89-1.12, P=0.991) and for secondary end-point death within 30 days (HR 1.03; 95% CI 0.85-1.25, P=0.735). The risks of developing cardiogenic shock, stent thrombosis, or in-stent restenosis were similar between the groups.In our region, short- and long-term prognosis for patients with STEMI who undergo primary PCI is similar for patients presenting during off-hours and regular hours.
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