| 1. |
- Connolly, L. J., et al.
(författare)
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Effects of small-volume soccer and vibration training on body composition, aerobic fitness, and muscular PCr kinetics for inactive women aged 20-45
- 2014
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Ingår i: Journal of Sport and Health Science. - : Elsevier BV. - 2095-2546. ; 3:4, s. 284-292
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The present study investigated the effects of 16 weeks of small-volume, small-sided soccer training soccer group (SG, n = 13) and oscillating whole-body vibration training vibration group (VG, n = 17) on body composition, aerobic fitness, and muscle PCr kinetics in healthy inactive premenopausal women in comparison with an inactive control group (CO, n = 14). Methods: Training for SG and VG consisted of twice-weekly 15-min sessions with average heart rates (HRs) of similar to 155 and 90 bpm respectively. Pre- and post-measurements of body composition (DXA), phosphocreatine (PCr) on-and off-kinetics, and HR measurements during standardised submaximal exercise were performed. Results: After 16 weeks of training in SG, fat percentage was lowered (p = 0.03) by 1.7% +/- 2.4% from 37.5% +/- 6.9% to 35.8% +/- 6.2% and the PCr decrease in the quadriceps during knee-extension ramp exercise was attenuated (4% +/- 8%, p = 0.04), with no changes in VG or CO (time-group effect: p = 0.03 and p = 0.03). Submaximal exercise HR was also reduced in SG after 16 weeks of training (6% +/- 5% of HRmax, p = 0.01). Conclusion: Short duration soccer training for 16 weeks appears to be sufficient to induce favourable changes in body composition and indicators of aerobic fitness and muscle oxidative capacity in untrained premenopausal women. Copyright (C) 2014, Shanghai University of Sport. Production and hosting by Elsevier B.V. All rights reserved.
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| 2. |
- Vanhatalo, A., et al.
(författare)
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The mechanistic bases of the power–time relationship: muscle metabolic responses and relationships to muscle fibre type
- 2016
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Ingår i: Journal of Physiology. - 0022-3751. ; 594:15, s. 4407-4423
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Tidskriftsartikel (refereegranskat)abstract
- Key points: The power-asymptote (critical power; CP) of the hyperbolic power–time relationship for high-intensity exercise defines a threshold between steady-state and non-steady-state exercise intensities and the curvature constant (W′) indicates a fixed capacity for work >CP that is related to a loss of muscular efficiency. The present study reports novel evidence on the muscle metabolic underpinnings of CP and W′ during whole-body exercise and their relationships to muscle fibre type. We show that the W′ is not correlated with muscle fibre type distribution and that it represents an elevated energy contribution from both oxidative and glycolytic/glycogenolytic metabolism. We show that there is a positive correlation between CP and highly oxidative type I muscle fibres and that muscle metabolic steady-state is attainable CP. Our findings indicate a mechanistic link between the bioenergetic characteristics of muscle fibre types and the power–time relationship for high-intensity exercise. Abstract: We hypothesized that: (1) the critical power (CP) will represent a boundary separating steady-state from non-steady-state muscle metabolic responses during whole-body exercise and (2) that the CP and the curvature constant (W′) of the power–time relationship for high-intensity exercise will be correlated with type I and type IIx muscle fibre distributions, respectively. Four men and four women performed a 3min all-out cycling test for the estimation of CP and constant work rate (CWR) tests slightly >CP until exhaustion (Tlim), slightly CP Tlim isotime to test the first hypothesis. Eleven men performed 3min all-out tests and donated muscle biopsies to test the second hypothesis. Below CP, muscle [PCr] [42.6±7.1vs. 49.4±6.9mmol(kgd.w.)−1], [La−] [34.8±12.6vs. 35.5±13.2mmol(kgd.w.)−1] and pH (7.11±0.08 vs. 7.10±0.11) remained stable between ∼12 and 24min (P>0.05 for all), whereas these variables changed with time >CP such that they were greater [[La−] 95.6±14.1mmol(kgd.w.)−1] and lower [[PCr] 24.2±3.9mmol(kgd.w.)−1; pH 6.84±0.06] (P<0.05) at Tlim (740±186s) than during the
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| 3. |
- Bendiksen, M., et al.
(författare)
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Application of the Copenhagen Soccer Test in high-level women players - locomotor activities, physiological response and sprint performance
- 2013
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Ingår i: Human Movement Science. - : Elsevier BV. - 0167-9457. ; 32:6, s. 1430-1442
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated the physiological response, sprint performance and technical ability in various phases of the Copenhagen Soccer Test for Women (CSTw.) and investigated whether the locomotor activities of the CSTw were comparable to competitive match-play (CM). Physiological measurements and physical/technical assessments were performed during CSTw for eleven Norwegian high-level women soccer players. The activity pattern during CSTw and CM was monitored using the ZXY tracking system. No differences were observed between CSTw and CM with regards to total distance covered (10093 +/- 94 and 9674 +/- 191 m), high intensity running (1278 +/- 67 and 1193 +/- 115 m) or sprinting (422 +/- 55 and 372 +/- 46 m) (p > .05). During CSTw, average HR was 85 +/- 2%HRmax with 35 +/- 2% playing time >90%HRmax. Blood lactate increased (p < .05) from 1.4 +/- 0.3 mM at rest to an average of 4.7 +/- 0.5 mM during CSTw, with no changes during the test. Blood glucose was 5.4 +/- 0.3 mM at rest and remained unaltered during CSTw. Sprint performance (2 x 20 in) decreased (p < .05) by 3% during CSTw (8.19 +/- 0.06-8.47 +/- 0.10 s). In conclusion, the locomotor activities during CSTw were comparable to that of high-level competitive match-play. The physiological demands of the CSTw were high, with no changes in heart rate, blood lactate or technical performance during the test, but a lowered sprint performance towards the end of the test. (C) 2013 Elsevier B.V. All rights reserved.
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| 4. |
- Bangsbo, Jens, et al.
(författare)
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Copenhagen Consensus statement 2019 : physical activity and ageing
- 2019
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Ingår i: British Journal of Sports Medicine. - London : BMJ Publishing Group Ltd. - 0306-3674 .- 1473-0480. ; 53:14, s. 856-858
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Tidskriftsartikel (refereegranskat)abstract
- From 19th to 22nd November 2018, 26 researchers representing nine countries and a variety of academic disciplines met in Snekkersten, Denmark, to reach evidence-based consensus about physical activity and older adults. It was recognised that the term ‘older adults’ represents a highly heterogeneous population. It encompasses those that remain highly active and healthy throughout the life-course with a high intrinsic capacity to the very old and frail with low intrinsic capacity. The consensus is drawn from a wide range of research methodologies within epidemiology, medicine, physiology, neuroscience, psychology and sociology, recognising the strength and limitations of each of the methods. Much of the evidence presented in the statements is based on longitudinal associations from observational and randomised controlled intervention studies, as well as quantitative and qualitative social studies in relatively healthy community-dwelling older adults. Nevertheless, we also considered research with frail older adults and those with age-associated neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease, and in a few cases molecular and cellular outcome measures from animal studies. The consensus statements distinguish between physical activity and exercise. Physical activity is used as an umbrella term that includes both structured and unstructured forms of leisure, transport, domestic and work-related activities. Physical activity entails body movement that increases energy expenditure relative to rest, and is often characterised in terms of intensity from light, to moderate to vigorous. Exercise is defined as a subset of structured physical activities that are more specifically designed to improve cardiorespiratory fitness, cognitive function, flexibility balance, strength and/or power. This statement presents the consensus on the effects of physical activity on older adults’ fitness, health, cognitive functioning, functional capacity, engagement, motivation, psychological well-being and social inclusion. It also covers the consensus on physical activity implementation strategies. While it is recognised that adverse events can occur during exercise, the risk can be minimised by carefully choosing the type of activity undertaken and by consultation with the individual’s physician when warranted, for example, when the individual is frail, has a number of co-morbidities, or has exercise-related symptoms, such as chest pain, heart arrhythmia or dizziness. The consensus was obtained through an iterative process that began with the presentation of the state-of-the-science in each domain, followed by group and plenary discussions. Ultimately, the participants reached agreement on the 30-item consensus statements.
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| 5. |
- Hansen, M., et al.
(författare)
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Protein intake during training sessions has no effect on performance and recovery during a strenuous training camp for elite cyclists
- 2016
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Ingår i: Journal of the International Society of Sports Nutrition. - : Informa UK Limited. - 1550-2783. ; 13:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Training camps for top-class endurance athletes place high physiological demands on the body. Focus on optimizing recovery between training sessions is necessary to minimize the risk of injuries and improve adaptations to the training stimuli. Carbohydrate supplementation during sessions is generally accepted as being beneficial to aid performance and recovery, whereas the effect of protein supplementation and timing is less well understood. We studied the effects of protein ingestion during training sessions on performance and recovery of elite cyclists during a strenuous training camp. Methods: In a randomized, double-blinded study, 18 elite cyclists consumed either a whey protein hydrolysate-carbohydrate beverage (PRO-CHO, 14 g protein/h and 69 g CHO/h) or an isocaloric carbohydrate beverage (CHO, 84 g/h) during each training session for six days (25-29 h cycling in total). Diet and training were standardized and supervised. The diet was energy balanced and contained 1.7 g protein/kg/day. A 10-s peak power test and a 5-min all-out performance test were conducted before and after the first training session and repeated at day 6 of the camp. Blood and saliva samples were collected in the morning after overnight fasting during the week and analyzed for biochemical markers of muscle damage, stress, and immune function. Results: In both groups, 5-min all-out performance was reduced after the first training session and at day 6 compared to before the first training session, with no difference between groups. Peak power in the sprint test did not change significantly between tests or between groups. In addition, changes in markers for muscle damage, stress, and immune function were not significantly influenced by treatment. Conclusions: Intake of protein combined with carbohydrate during cycling at a training camp for top cyclists did not result in marked performance benefits compared to intake of carbohydrates when a recovery drink containing adequate protein and carbohydrate was ingested immediately after each training session in both groups. These findings suggest that the addition of protein to a carbohydrate supplement consumed during exercise does not improve recovery or performance in elite cyclists despite high demands of daily exhaustive sessions during a one-week training camp.
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| 6. |
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| 7. |
- Krustrup, P., et al.
(författare)
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The Yo-Yo IE2 Test: Physiological Response for Untrained Men versus Trained Soccer Players
- 2015
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Ingår i: Medicine and Science in Sports and Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131. ; 47:1, s. 100-108
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Tidskriftsartikel (refereegranskat)abstract
- Purpose This study aimed to examine the physical capacity and physiological response to the Yo-Yo Intermittent Endurance level 2 test (IE2) for untrained individuals (UTR) and trained male soccer players (TR) and to investigate the determinants of intense intermittent exercise performance. Methods Thirty-four healthy UTR males and 15 age-matched TR performed a maximal incremental treadmill test and a Yo-Yo IE2 test. Muscle biopsies and blood samples were obtained, and heart rate (HR) was measured before, during, and after tests. Results UTR had a 67% lower (P < 0.01) Yo-Yo IE2 performance (665 271 vs 2027 +/- 298 m; effect size (ES), 4.8), 34% lower VO2max (P < 0.01), and 19% lower resting muscle glycogen (P < 0.05) than those of TR. Blood lactate concentration and HR during the first 560 m of the Yo-Yo IE2 test were higher (P < 0.01) in UTR than those in TR (560 m, 7.4 +/- 2.8 vs 2.4 +/- 0.8 mM; ES, 1.7-2.8; 188 +/- 11 vs 173 +/- 8 bpm; ES, 0.9-1.5), with no differences at exhaustion. Time >95% HRmax was lower (P < 0.01) in UTR than that in TR (1.0 +/- 1.1 vs 6.3 +/- 2.9 min; ES, 3.1). Mean rates of muscle creatine phosphate utilization (16.5 +/- 9.5 vs 4.3 +/- 2.7 mmolkg(-1) d.wmin(-1)), muscle lactate accumulation (16.8 +/- 9.1 vs 4.2 +/- 2.9 mmolkg(-1) d.w.min(-1)), and glycogen breakdown (29.6 +/- 14.2 vs 7.7 +/- 5.4 mmolkg(-1) d.w.min(-1)) were fourfold higher (P < 0.01; ES, 1.4-1.7) in UTR than those in TR. For UTR, correlations (P < 0.01) were observed between Yo-Yo IE2 performance and VO2max (r = 0.77), incremental treadmill test performance (r = 0.79), and muscle citrate synthase activity (r = 0.57) but not for TR (r = -0.12 to 0.50; P > 0.05). Conclusions The Yo-Yo IE2 test was shown to possess high construct validity by showing large differences in performance, HR, and anaerobic metabolism between UTR and TR. In addition, VO2max seemed to be important for intermittent exercise performance in UTR but not for TR.
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| 8. |
- Pettersen, S. A., et al.
(författare)
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Caffeine supplementation does not affect match activities and fatigue resistance during match play in young football players
- 2014
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Ingår i: Journal of Sports Sciences. - : Informa UK Limited. - 0264-0414 .- 1466-447X. ; 32:20, s. 1958-1965
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Tidskriftsartikel (refereegranskat)abstract
- The study examined the effect of caffeine supplementation on match activities and development of fatigue during a football match. In a randomised, double-blind cross-over design, two experimental football games separated by 7days were organised between the junior teams of two professional football clubs (17.6 +/- 1.1years (+/- s), 71.7 +/- 6.9kg, 13.9%+/- 5.0% body fat). The players ingested either a capsule of 6mg center dot kg(-1)b.w. caffeine or placebo (dextrose) 65min prior to the matches. Match activities were assessed using the ZXY match analysis system, and a Yo-Yo intermittent recovery test-level 2 (Yo-Yo IR2) was conducted immediately post-game. Heart rate was monitored throughout the game, and blood samples were obtained at baseline, half-time and after the game. There were no differences between caffeine and placebo regarding total distance covered (10,062 +/- 916 vs 9854 +/- 901m), high-intensity running (557 +/- 178 vs 642 +/- 240m), sprinting distance (109 +/- 58 vs 112 +/- 69m) or acceleration counts (123 +/- 31 vs 126 +/- 24). In both trials, players displayed lower (P<0.05) values in total distance and acceleration counts in the last 15min compared to all other 15-min periods of the matches. Post-game Yo-Yo IR2 performance was not different between game trials (caffeine: 829 +/- 322m; placebo 819 +/- 289m). In conclusion, oral caffeine administration does not appear to have an ergogenic effect in young football players during match play.
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| 9. |
- Bozek, Katarzyna, et al.
(författare)
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Exceptional evolutionary divergence of human muscle and brain metabolomes parallels human cognitive and physical uniqueness.
- 2014
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Ingår i: PLoS Biology. - : Public Library of Science (PLoS). - 1545-7885. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Metabolite concentrations reflect the physiological states of tissues and cells. However, the role of metabolic changes in species evolution is currently unknown. Here, we present a study of metabolome evolution conducted in three brain regions and two non-neural tissues from humans, chimpanzees, macaque monkeys, and mice based on over 10,000 hydrophilic compounds. While chimpanzee, macaque, and mouse metabolomes diverge following the genetic distances among species, we detect remarkable acceleration of metabolome evolution in human prefrontal cortex and skeletal muscle affecting neural and energy metabolism pathways. These metabolic changes could not be attributed to environmental conditions and were confirmed against the expression of their corresponding enzymes. We further conducted muscle strength tests in humans, chimpanzees, and macaques. The results suggest that, while humans are characterized by superior cognition, their muscular performance might be markedly inferior to that of chimpanzees and macaque monkeys.
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| 10. |
- Fernström, Maria, et al.
(författare)
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Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume
- 2009
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Ingår i: Journal of applied physiology (Bethesda, Md. : 1985). - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 106:1, s. 73-80
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Tidskriftsartikel (refereegranskat)abstract
- We studied the effect of an alteration from regular endurance to speed endurance training on muscle oxidative capacity, capillarization, as well as energy expenditure during submaximal exercise and its relationship to mitochondrial uncoupling protein 3 (UCP3) in humans. Seventeen endurance-trained runners were assigned to either a speed endurance training (SET; n = 9) or a control (Con; n = 8) group. For a 4-wk intervention (IT) period, SET replaced the ordinary training (∼45 km/wk) with frequent high-intensity sessions each consisting of 8–12 30-s sprint runs separated by 3 min of rest (5.7 ± 0.1 km/wk) with additional 9.9 ± 0.3 km/wk at low running speed, whereas Con continued the endurance training. After the IT period, oxygen uptake was 6.6, 7.6, 5.7, and 6.4% lower ( P < 0.05) at running speeds of 11, 13, 14.5, and 16 km/h, respectively, in SET, whereas remained the same in Con. No changes in blood lactate during submaximal running were observed. After the IT period, the protein expression of skeletal muscle UCP3 tended to be higher in SET (34 ± 6 vs. 47 ± 7 arbitrary units; P = 0.06). Activity of muscle citrate synthase and 3-hydroxyacyl-CoA dehydrogenase, as well as maximal oxygen uptake and 10-km performance time, remained unaltered in both groups. In SET, the capillary-to-fiber ratio was the same before and after the IT period. The present study showed that speed endurance training reduces energy expenditure during submaximal exercise, which is not mediated by lowered mitochondrial UCP3 expression. Furthermore, speed endurance training can maintain muscle oxidative capacity, capillarization, and endurance performance in already trained individuals despite significant reduction in the amount of training.
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