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- Datson, Naomi, et al.
(författare)
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Applied physiology of female soccer : an update.
- 2014
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Ingår i: Sports Medicine. - : Springer Science and Business Media LLC. - 0112-1642 .- 1179-2035. ; 44:9, s. 1225-40
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Tidskriftsartikel (refereegranskat)abstract
- The popularity and professionalism of female soccer has increased markedly in recent years, with elite players now employed on either a professional or semi-professional basis. The previous review of the physiological demands of female soccer was undertaken two decades ago when the sport was in its relative infancy. Increased research coupled with greater training and competition demands warrants an updated review to consider the effect on physical performance and injury patterns. The physical demands of match-play along with the influence of factors such as the standard of competition, playing position and fatigue have been explored. Total distance covered for elite female players is approximately 10 km, with 1.7 km completed at high speed (>15 kmh(-1)) [corrected].Elite players complete 28% more high-speed running and 24 % more sprinting than moderate-level players. Decrements in high-speed running distance have been reported between and within halves, which may indicate an inability to maintain high-intensity activity. Although the physical capacity of female players is the most thoroughly researched area, comparisons are difficult due to differing protocols. Elite players exhibit maximal oxygen uptake (VO2max) values of 49.4-57.6 mL·kg(-1)·min(-1), Yo Yo Intermittent Endurance test level 2 (YYIE2) scores of 1,774 ± 532 m [mean ± standard deviation (SD)] and 20 m sprint times of 3.17 ± 0.03 s (mean ± SD). Reasons for the increased prevalence of anterior cruciate ligament injuries in females (2-6 times greater than males) are discussed, with anatomical, biomechanical loading and neuromuscular activation differences being cited in the literature. This review presents an in-depth contemporary examination of the applied physiology of the female soccer player.
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| 2. |
- Lundqvist, Carolina, 1977-, et al.
(författare)
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A worldwide survey of perspectives on demands, resources, and barriers influencing the youth-to-senior transition in academy football players
- 2024
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Ingår i: International journal of sports science & coaching. - : Sage Publications. - 1747-9541 .- 2048-397X. ; 19:1, s. 162-170
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Tidskriftsartikel (refereegranskat)abstract
- The youth-to-first team phase presents a number of challenges in the careers of modern football players with stagnation, inconsistent performance and dropout being reported. The aim of this study was to investigate the perception of staff involved in professional academy football clubs around the globe, with a particular focus on youth and first team transition demands, resources as well as transitions barriers and coping among male academy football players. Participants from 29 male youth academies distributed across 29 countries took part in the survey. Our main findings suggested training and match intensity reported as being greater at the senior-level and also pressure from parents. The majority of respondents indicated their clubs having long-term strategy for player development and specific roles supporting successful player transitions. Exposure to different playing styles was deemed important to prepare players for the first team. Likewise, having the academy and the first team training on the same site was perceived to ease the transition, with the majority of respondents indicating that players are able to cope with the pressure of first team training and games. Perceptions on whether staff do not have the skills/resources to prepare players for the changes in environment and culture when players move from youth-to-senior level were unclear. Collectively, our study extends previous transition research on youth football academies suggesting the importance of a club-based playing philosophy to prepare players for the first team demands and challenges.
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| 3. |
- Mawhinney, Chris, et al.
(författare)
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Cool-Water Immersion Reduces Postexercise Quadriceps Femoris Muscle Perfusion More Than Cold-Water Immersion
- 2022
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Ingår i: Medicine & Science in Sports & Exercise. - Philadelphia, PA : Lippincott Williams & Wilkins. - 0195-9131 .- 1530-0315. ; 54:7, s. 1085-1094
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The muscle perfusion response to postexercise cold-water immersion (CWI) is not well understood. We examined the effects of graded postexercise CWI upon global and regional quadriceps femoris muscle perfusion using positron emission tomography and [15O]H2O. Methods: Using a matched-group design, 30 healthy men performed cycle ergometer exercise at 70% VO2peak to a core body temperature of 38°C, followed by either 10 min of CWI at 8°C, 22°C, or seated rest (control). Quadriceps muscle perfusion; thigh and calf cutaneous vascular conductance; intestinal, muscle, and local skin temperatures; thermal comfort; mean arterial pressure; and heart rate were assessed at preexercise, postexercise, and after CWI. Results: Global quadriceps perfusion was reduced beyond the predefined minimal clinically relevant threshold (0.75 mL per 100 g·min-1) in 22°C water versus control (difference (95% confidence interval (CI)), -2.5 (-3.9 to -1.1) mL per 100 g·min-1). Clinically relevant decreases in muscle perfusion were observed in the rectus femoris (-2.0 (-3.0 to -1.0) mL per 100 g·min-1) and vastus lateralis (-3.5 (-4.9 to -2.0) mL per 100 g·min-1) in 8°C water, and in the vastus lateralis (-3.3 (-4.8 to -1.9) mL per 100 g·min-1) in 22°C water versus control. The mean effects for vastus intermedius and vastus medialis perfusion were not clinically relevant. Clinically relevant decreases in thigh and calf cutaneous vascular conductance were observed in both cooling conditions. Conclusions: The present findings revealed that less noxious CWI (22°C) promoted clinically relevant postexercise decreases in global quadriceps muscle perfusion, whereas noxious cooling (8°C) elicited no effect. © Lippincott Williams & Wilkins
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| 4. |
- Zheng, Hou-Feng, et al.
(författare)
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Whole-genome sequencing identifies EN1 as a determinant of bone density and fracture
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 526:7571, s. 112-
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Tidskriftsartikel (refereegranskat)abstract
- The extent to which low-frequency (minor allele frequency (MAF) between 1-5%) and rare (MAF <= 1%) variants contribute to complex traits and disease in the general population is mainly unknown. Bone mineral density (BMD) is highly heritable, a major predictor of osteoporotic fractures, and has been previously associated with common genetic variants(1-8), as well as rare, population specific, coding variants(9). Here we identify novel non-coding genetic variants with large effects on BMD (n(total) = 53,236) and fracture (n(total) = 508,253) in individuals of European ancestry from the general population. Associations for BMD were derived from whole-genome sequencing (n = 2,882 from UK10K (ref. 10); a population-based genome sequencing consortium), whole-exome sequencing (n = 3,549), deep imputation of genotyped samples using a combined UK10K/1000 Genomes reference panel (n = 26,534), and de novo replication genotyping (n = 20,271). We identified a low-frequency non-coding variant near a novel locus, EN1, with an effect size fourfold larger than the mean of previously reported common variants for lumbar spine BMD8 (rs11692564(T), MAF51.6%, replication effect size510.20 s.d., P-meta = 2 x 10(-14)), which was also associated with a decreased risk of fracture (odds ratio = 0.85; P = 2 x 10(-11); ncases = 98,742 and ncontrols = 409,511). Using an En1cre/flox mouse model, we observed that conditional loss of En1 results in low bone mass, probably as a consequence of high bone turnover. We also identified a novel low frequency non-coding variant with large effects on BMD near WNT16 (rs148771817(T), MAF = 1.2%, replication effect size +10.41 s.d., P-meta = 1 x 10(-11)). In general, there was an excess of association signals arising from deleterious coding and conserved non-coding variants. These findings provide evidence that low-frequency non-coding variants have large effects on BMD and fracture, thereby providing rationale for whole-genome sequencing and improved imputation reference panels to study the genetic architecture of complex traits and disease in the general population.
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