| 1. |
- Andersson, Helena M, et al.
(författare)
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Elite football on artificial turf versus natural grass : movement patterns, technical standards, and player impressions
- 2008
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Ingår i: Journal of Sports Sciences. - : Informa UK Limited. - 0264-0414 .- 1466-447X. ; 26:2, s. 113-22
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to examine the movement patterns, ball skills, and the impressions of Swedish elite football players during competitive games on artificial turf and natural grass. Time - motion analyses (36 observations) and technical analyses (16 team observations) were performed and 72 male and 21 female players completed a questionnaire. No differences were observed between artificial turf and natural grass in terms of total distance covered (mean 10.19 km, s = 0.19 vs. 10.33 km, s = 0.23), high-intensity running (1.86 km, s = 0.10 vs. 1.87 km, s = 0.14), number of sprints (21, s = 1 vs. 22, s = 2), standing tackles (10, s = 1 vs. 11, s = 1) or headers per game (8, s = 1 vs. 8, s = 1), whereas there were fewer sliding tackles (P < 0.05) on artificial turf than natural grass (2.1, s = 0.5 vs. 4.3, s = 0.6). There were more short passes (218, s = 14 vs. 167, s = 12) and midfield-to-midfield passes (148, s = 11 vs. 107, s = 8) (both P < 0.05) on artificial turf than natural grass. On a scale of 0-10, where 0 = "better than", 5 = "equal to", and 10 = "worse than", the male players reported a negative overall impression (8.3, s = 0.2), poorer ball control (7.3, s = 0.3), and greater physical effort (7.2, s = 0.2) on artificial turf than natural grass. In conclusion, the running activities and technical standard were similar during games on artificial turf and natural grass. However, fewer sliding tackles and more short passes were performed during games on artificial turf. The observed change in playing style could partly explain the male players' negative impression of artificial turf.
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| 2. |
- Mascher, Henrik, et al.
(författare)
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Changes in signalling pathways regulating protein synthesis in human muscle in the recovery period after endurance exercise
- 2007
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Ingår i: Acta Physiologica. - : Blackwel. - 1748-1708 .- 1748-1716. ; 191:1, s. 67-75
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Tidskriftsartikel (refereegranskat)abstract
- AIM: Exercise induced alterations in the rate of muscle protein synthesis may be related to activity changes in signalling pathways involved in protein synthesis. The aim of the present study was to investigate whether such changes in enzyme phosphorylation occur after endurance exercise. METHODS: Six male subjects performed ergometer cycling exercise for 1 h at 75% of the maximal oxygen uptake. Muscle biopsy samples from the vastus lateralis were taken before, immediately after, 30 min, 1 h, 2 h and 3 h after exercise for the determination of protein kinase B (PKB/Akt), mammalian target of rapamycin (mTOR), glycogen synthase 3 kinase (GSK-3), p70S6 kinase (p70(S6k)) and eukaryotic elongation factor 2 (eEF2) phosphorylation. RESULTS: The phosphorylation of Akt was unchanged directly after exercise, but two- to fourfold increased 1 and 2 h after the exercise, whereas GSK-3alpha and beta phosphorylation were two- to fourfold elevated throughout most of the 3-h recovery period. Phosphorylation of mTOR was elevated threefold directly after, 30 min and 2 h after exercise and eEF2 phosphorylation was decreased by 35-75% from 30 min to 3 h-recovery. Exercise led to a five- to eightfold increase in Ser(424)/Thr(421) phosphorylation of p70(S6k) up to 30 min after exercise, but no change in Thr(389) phosphorylation. CONCLUSIONS: The marked decrease in eEF2 phosphorylation suggests an activation of translation elongation and possibly protein synthesis in the recovery period after sustained endurance exercise. The lack of p70(S6k) activation suggests that translation initiation is activated via alternative pathways, possibly via the activation of eukaryotic initiating factor 2B.
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| 3. |
- Mohr, Magni, et al.
(författare)
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Match activities of elite women soccer players at different performance levels
- 2008
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Ingår i: Journal of Strength and Conditioning Research. - : Wolters Kluwer. - 1064-8011 .- 1533-4287. ; 22:2, s. 341-349
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Tidskriftsartikel (refereegranskat)abstract
- We sought to study the physical demands and match performance of women soccer players. Nineteen top-class and 15 high-level players were individually videotaped in competitive matches, and time-motion analysis were performed. The players changed locomotor activity >1,300 times in a game corresponding to every ~4 seconds and covered 9-11 km in total. The top-class players ran 28% longer (P < 0.05) at high intensities than high-level players (1.68 +/- 0.09 and 1.33 +/- 0.10 km, respectively) and sprinted 24% longer (P < 0.05). The top-class group had a decrease (P < 0.05) of 25-57% in high intensity running in the final 15 minutes compared with the first four 15-minutes intervals, whereas the high-level group performed less (P < 0.05) high-intensity running in the last 15 minutes of each half in comparison with the 2 previous 15-minute periods in the respective half. Peak distance covered by high intensity running in a 5-minute interval was 33% longer (P < 0.05) for the top-class players than the high-level players. In the following 5 minutes immediately after the peak interval top-class players covered 17% less (P < 0.05) high-intensity running than the game average. Defenders performed fewer (P < 0.05) intervals of high-intensity running than midfielders and attackers, as well as fewer (P < 0.05) sprints than the attackers. In conclusion, for women soccer players (1) top-class international players perform more intervals of high-intensity running than elite players at a lower level, (2) fatigue develops temporarily during and towards the end of a game, and (3) defenders have lower work rates than midfielders and attackers. The difference in high-intensity running between the 2 levels demonstrates the importance of intense intermittent exercise for match performance in women soccer. Thus, these aspects should be trained intensively in women soccer.
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| 4. |
- Almqvist, Jonas, et al.
(författare)
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Pragmatic investigation : studies of meaning-making in educational practices
- 2008
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Konferensbidrag (populärvet., debatt m.m.)abstract
- The overall aim of this paper is to present and discuss a pragmatic approach for studies of meaning-making in different educational practices. The approach – built on a framework developed within the SMED-group (Studies of Meaning-making in Educational Discourses) at the universities of Uppsala and Örebro – is illustrated in a number of empirical studies. The main point of departure in the studies is taken in pragmatic curriculum theory and sociocultural perspectives on learning, and is inspired mainly by John Dewey, Ludwig Wittgenstein and Michel Foucault. A special focus is directed to communication practices and content selection within Physical education, Environmental education and Science education. A common ambition is to offer a language that enables studies and discussions on questions concerning how meanings are made in people’s actions. Another ambition is to make these investigations beyond assumptions of dualisms, essentialism, causality and determinism. In this perspective learning and socialisation is viewed in communicative perspective. Therefore, many of the studies are built on video recorded classroom conversations, but also on analysis of various kinds of written texts. We argue in the paper that this approach makes it possible to study meaning-making – learning and socialisation – in different kinds of educational practices.
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| 5. |
- Ambrosio, Fabrisia, et al.
(författare)
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The effect of muscle loading on skeletal muscle regenerative potential : an update of current research findings relating to aging and neuromuscular pathology
- 2009
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Ingår i: American Journal of Physical Medicine & Rehabilitation. - Baltimore : Lippincott Williams & Wilkins. - 0894-9115 .- 1537-7385. ; 88:2, s. 145-155
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Forskningsöversikt (refereegranskat)abstract
- Skeletal muscle is a dynamic tissue with a remarkable ability to continuously respond to environmental stimuli. Among its adaptive responses is the widely investigated ability of skeletal muscle to regenerate after loading or injury or both. Although significant basic science efforts have been dedicated to better understand the underlying mechanism controlling skeletal muscle regeneration, there has been relatively little impact in the clinical approaches used to treat skeletal muscle injuries and wasting. The purpose of this review article is to provide an overview of the basic biology of satellite cell function in response to muscle loading and to relate these findings in the context of aging and neuromuscular pathology for the rehabilitation medicine specialist.
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| 6. |
- Andersson, Helena M., et al.
(författare)
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Differences in the inflammatory plasma cytokine response following two elite female soccer games separated by a 72-h recovery
- 2010
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - Malden, USA : Wiley-Blackwell. - 0905-7188 .- 1600-0838. ; 20:5, s. 740-747
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Tidskriftsartikel (refereegranskat)abstract
- We investigated changes in a large battery of pro- and anti-inflammatory cytokines in elite female soccer players following two 90-min games separated by a 72-h active or passive recovery. Blood samples were taken from 10 players before, within 15-20 min, 21, 45 and 69 h after the first game and within 15-20 min after the second game. The leukocyte count was analyzed, together with several plasma pro- and anti-inflammatory cytokines, using a multiplex bead array system. After the first and second game, the total leukocytes and neutrophils increased significantly. Likewise, increases (P<0.05) in pro-inflammatory cytokines [interleukin (IL)-12, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (INF-gamma), IL-17], chemokines [monocyte chemotactic protein-1 (MCP-1), IL-8 and monokine induced by gamma interferon (MIG)], anti-inflammatory cytokines (IL-2R, IL-4, IL-5, IL-7, IL-10, IL-13, INF-alpha) and the mixed cytokine IL-6 were observed. Leukocyte and cytokine levels were normalized within 21 h. Active recovery (low-intensity exercises) did not affect the cytokine responses. A dampened cytokine response was observed after the second game as only IL-12, IL-6, MCP-1, IL-8 and MIG increased (P<0.05). In conclusion, a robust pro- and anti-inflammatory cytokine response occurs after the first but not the second soccer game. The implications of the dampened cytokine response in female players after the second game are unknown.
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| 7. |
- Andersson, Helena M., et al.
(författare)
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Neuromuscular fatigue and recovery in elite female soccer : effects of active recovery
- 2008
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Ingår i: Medicine & Science in Sports & Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131 .- 1530-0315. ; 40:2, s. 372-380
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate the time course of recovery from neuromuscular fatigue and some biochemical changes between two female soccer matches separated by an active or passive recovery regime. METHODS: Countermovement jump (CMJ), sprint performance, maximal isokinetic knee flexion and extension, creatine kinase (CK), urea, uric acid, and perceived muscle soreness were measured in 17 elite female soccer players before, immediately after, 5, 21, 45, 51, and 69 h after a first match, and immediately after a second match. Eight players performed active recovery (submaximal cycling at 60% of HRpeak and low-intensity resistance training at < 50% 1RM) 22 and 46 h after the first match. RESULTS: In response to the first match, a significant decrease in sprint performance (-3.0 +/- 0.5%), CMJ (-4.4 +/- 0.8%), peak torque in knee extension (-7.1 +/- 1.9%) and flexion (-9.4 +/- 1.8%), and an increase in CK (+ 152 +/- 28%), urea (15 +/- 2), uric acid (+ 11 +/- 2%), and muscle soreness occurred. Sprint ability was first to return to baseline (5 h) followed by urea and uric acid (21 h), isokinetic knee extension (27 h) and flexion (51 h), CK, and muscle soreness (69 h), whereas CMJ was still reduced at the beginning of the second match. There were no significant differences in the recovery pattern between the active and passive recovery groups. The magnitude of the neuromuscular and biochemical changes after the second match was similar to that observed after the first match. CONCLUSION: The present study reveals differences in the recovery pattern of the various neuromuscular and biochemical parameters in response to a female soccer match. The active recovery had no effects on the recovery pattern of the four neuromuscular and three biochemical parameters.
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| 8. |
- Andersson, Helena M., et al.
(författare)
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Plasma antioxidant responses and oxidative stress following a soccer game in elite female players
- 2010
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - Malden, USA : Wiley-Blackwell. - 0905-7188 .- 1600-0838. ; 20:4, s. 600-608
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to investigate markers of oxidative stress and levels of endogenous and dietary antioxidants in 16 elite female soccer players in response to a 90-min game (average intensity 82+/-3% HRpeak). Blood samples were taken before, immediately and 21 h after the game. Plasma-oxidized glutathione, the ratio of reduced to oxidized glutathione (GSH:GSSG) and lipid peroxidation measured by d-ROMs were used as markers of oxidative stress. Plasma endogenous [uric acid, total glutathione (TGSH)] and dietary antioxidants (alpha-tocopherol, ascorbic acid, total carotenoids and polyphenols) were analyzed using liquid chromatography and the Folin-Ciocalteu method. Exercise induced an acute increase (P<0.05) in GSSG, uric acid, TGSH, alpha-tocopherol, and ascorbic acid. In parallel, the GSH:GSSG ratio and polyphenols decreased (P<0.05). GSSG, GSH:GSSG ratio, uric acid, TGSH, and ascorbic acid returned to baseline at 21 h, while polyphenols and alpha-tocopherol remained altered. Total carotenoids increased above baseline only at 21 h (P<0.05). Lipid peroxidation, measured by d-ROMs, remained unchanged throughout the study. Thus, intermittent exercise in well-trained female athletes induces a transient increase in GSSG and a decrease in the GSH:GSSG ratio, which is effectively balanced by the recruitment of both endogenous and dietary antioxidants, resulting in the absence of lipid peroxidation measured by d-ROMs.
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| 9. |
- Andersson, Helena M., 1973-
(författare)
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The physiological impact of soccer on elite female players and the effects of active recovery training
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Female soccer is becoming more popular and professional in the world. There are, however, limited scientific data available on how elite female players respond to physical stress during soccer games. An effective recovery strategy following a game is important, because there are few recovery days between the games in international tournaments. The present thesis, which was designed to mirror a competitive situation, aimed to investigate changes in several physiological systems occurring in female elite players in response to two soccer games. It also aimed to investigate the effects of active recovery training on the recovery of several physiological systems. METHODS: Two elite female soccer teams played two 90-min games separated by 72 h active or passive recovery. The active recovery training (cycling at 60% HRpeak, resistance training at <50% 1RM) lasted one hour and was performed 22 and 46 h after the first game. Countermovement jump (CMJ), 20-m sprint time and isokinetic knee strength were measured before, immediately, 5, 21, 45, 51, and 69 h after the first game, and immediately after the second game. The physical stress markers (CK, urea), oxidative stress markers (e.g., GSSG, lipid peroxidation), endogenous (e.g., UA, thiols) and dietary antioxidants (e.g., tocopherols, carotenoids) and a large battery of cytokines (e.g., IL-6, TNF-α) were analysed in blood. RESULTS: No significant differences were observed in the performance parameters, oxidative stress and antioxidant levels or inflammatory response between the active and passive recovery groups. Sprint and isokinetic knee strength were reduced by the same extent after both games. CMJ decreased after the first game and remained reduced throughout the study period. Blood physical stress markers, GSSG and endogenous antioxidants increased with similar amplitude after both games together with unchanged lipid peroxidation. The dietary antioxidants showed either a rapid and persistent change (e.g., tocopherols) or a delayed rise (carotenoids) after the first game. A transient increase occurred in several pro- (e.g., IL-12, TNF-a, MCP-1), anti-inflammatory (e.g., IL-4, IL-10, INF-a) and mixed (IL-6) cytokines after the first game. Fewer cytokines increased in response to the second game. CONCLUSION: Two repeated elite female soccer games separated by 72 h induced similar acute changes in several physiological parameters. After the first game, differences in the recovery pattern of the neuromuscular parameters occurred. In particular, the slow recovery of CMJ indicates that special attention should be devoted to the training of explosive force. Furthermore, the recruitment of antioxidants in response to the transient increase in GSSG resulted in the maintenance of the redox-balance in female players. Similarly, a strong and balanced pro- and anti-inflammatory cytokine response occurred after one single female soccer game. The consequences of the dampened cytokine response during repeated soccer games are, however, unknown. In general, the majority of the parameters had recovered prior to the second game and the physiological alterations induced by the first game did not affect the performance of players in the second game. Finally, active recovery training conducted after a soccer game does not accelerate the recovery time for neuromuscular, oxidative stress, antioxidant and inflammatory responses in elite female players.
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| 10. |
- Corder, Kirsten, et al.
(författare)
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Physical activity
- 2008. - 2
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Ingår i: Paediatric exercise science and medicine. - Oxford : Oxford University Press. - 9780199232482 ; , s. 129-144
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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