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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. |
- Nilsson, Jonna, et al.
(författare)
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Associations of cardiorespiratory fitness and moderate-to-vigorous physical activity with latent cognitive abilities in older adults
- 2022
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Ingår i: Psychology of Sport And Exercise. - : Elsevier. - 1469-0292 .- 1878-5476. ; 60, s. 102171-102171
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Tidskriftsartikel (refereegranskat)abstract
- It has been demonstrated that physical activity has a small but positive effect on cognition in old age, which suggests that it may be possible to alter the trajectory of age-related cognitive decline. However, our understanding of which aspects of physical activity that are important for modifying cognition remains incomplete. Adopting an exploratory approach in a sample of 115 healthy older adults (65–75 years), the present cross-sectional study used structural equation modelling to investigate the dissociable associations of physical activity (moderate-to-vigorous activity, derived from 7-day accelerometry) and cardiorespiratory fitness (VO2 max, derived from maximal treadmill ergometer test) with multiple latent cognitive abilities (working memory, episodic memory, spatial and verbal reasoning). The results showed a significant positive association between fitness and working memory, when physical activity was statistically controlled for, and a positive association of similar point magnitude between physical activity and episodic memory, when fitness was statistically controlled for, although the latter association did not reach statistical significance. The results add to the foundation for a more careful investigation of the dissociable associations of moderate-to-vigorous physical activity and fitness with cognition in old age, and encourages future research to test the hypothesis that cardiorespiratory fitness benefits working memory via general cerebrovascular effects on grey matter volume, whilst moderate-to-vigorous physical activity benefits episodic memory via effects on neuroplastic processes.
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| 4. |
- Wang, Rui, et al.
(författare)
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MRI load of cerebral microvascular lesions and neurodegeneration, cognitive decline, and dementia
- 2018
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Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 91:16, s. 1487-1497
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Tidskriftsartikel (refereegranskat)abstract
- Objective To explore the differential associations of neurodegeneration and microvascular lesion load with cognitive decline and dementia in older people and the modifying effect of the APOE genotype on these associations. Methods A sample of 436 participants (age >= 60 years) was derived from the population-based Swedish National study on Aging and Care in Kungsholmen, Stockholm, and clinically examined at baseline (2001-2003) and 3 occasions during the 9-year follow-up. At baseline, we assessed microvascular lesion load using a summary score for MRI markers of lacunes, white matter hyperintensities (WMHs), and perivascular spaces and neurodegeneration load for markers of enlarged ventricles, smaller hippocampus, and smaller gray matter. We assessed cognitive function using the Mini-Mental State Examination (MMSE) test and diagnosed dementia following the Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria. We analyzed data using linear mixed-effects, mediation, and random-effects Cox models. Results During the follow-up, 46 participants were diagnosed with dementia. Per 1-point increase in microvascular lesion and neurodegeneration score (range 0-3) was associated with multiple adjusted beta-coefficients of -0.35 (95% confidence interval, -0.51 to -0.20) and -0.44 (-0.56 to -0.32), respectively, for the MMSE score and multiple adjusted hazard ratios of 1.68 (1.12-2.51) and 2.35 (1.58-3.52), respectively, for dementia; carrying APOE epsilon 4 reinforced the associations with MMSE decline. WMH volume changes during the follow-up mediated 66.9% and 12.7% of the total association of MMSE decline with the baseline microvascular score and neurodegeneration score, respectively. Conclusions Both cerebral microvascular lesion and neurodegeneration loads are strongly associated with cognitive decline and dementia. The cognitive decline due to microvascular lesions is exacerbated by APOE epsilon 4 and is largely attributed to progression and development of microvascular lesions.
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| 5. |
- Mattsson, C. Mikael
(författare)
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Konditionsträning för lagbollsidrottare
- 2012
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Ingår i: Idrott & kunskap. - 1652-6961. ; :1, s. 46-49
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Vilka konditionstestvärden har elitspelare i fotboll, ishockey och basket? Och hur tränar man effektivast sinkondition om man är bollidrottare? Mikael Mattson, doktor i fysiologi vid GIH, reder ut begreppen.
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| 6. |
- Glas, Peter, et al.
(författare)
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Physiological requirements of elite handball – measured with a combination of local positioning system and heart rate monitoring.
- 2017
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Konferensbidrag (refereegranskat)abstract
- For all athletes, it is important to adjust training plans and competition schedule according to each individual's specific traits and situation. This is crucial in team sports, where players, despite being involved in the same sport, and even on the same team, may have very different physiological capacities and, also have completed a wide variety of work in both training and match situations. A first step towards being able to carry out individualized training is to accurately measure the amount of stress (physiological burden) for each individual. The purpose of the study was to create a comprehensive picture of the physical requirements of elite handball matches, and further investigate how the relationship between work load and physical capacity impacts performance.Heart rate measurements have since decades been used to quantify the relative work, and GPS measurement as a tool for objective values has been available for outdoor sports for about ten years, but GPS is not possible to use indoors. We have used a new technology with a similar system for indoor use called Local Positioning System (LPS) (Kinexon Precision Technologies, Münich, Germany) to record and analyze the players’ motion during games, and we have combined that technology with data from accelerometry, gyroscope and heart rate measurements.So far, 42 handball matches have been measured and analyzed, ranging from juniors (9 games U21 men's national team) to seniors, men and women, and both in Sweden’s highest league and between national teams (Women: 8 national and 7 international games; Men: 14 national and 4 international games).A first "result" is that the categorization of motion patterns need to be adapted to each sport. For example, some moves that should be counted as accelerations in handball are not recognized by the system, simply because it has been adapted to the pattern of motion on the much larger soccer field. This is similarly important to realize when comparing results for handball’s physiological requirements reached using other technologies. In this presentation, we will in part discuss the future technological opportunities, and in part report descriptive results, including how fast and far the players move, as well as differences between men and women, between national and international games, and between juniors and seniors.
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| 7. |
- 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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| 8. |
- Gilenstam, Kajsa M., 1974-, et al.
(författare)
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Physiological Correlates of Skating Performance in Women's and Men's Ice Hockey
- 2011
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Ingår i: Journal of Strength and Conditioning Research. - : National Strength and Conditioning Association. - 1064-8011 .- 1533-4287. ; 25:8, s. 2133-2142
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the current investigation was to identify relationships between physiological off-ice tests and on-ice performance in female and male ice hockey players on a comparable competitive level. Eleven women, 24 ± 3.0 years, and 10 male ice hockey players, 23 ± 2.4 years, were tested for background variables: height, body weight (BW), ice hockey history, and lean body mass (LBM) and peak torque (PT) of the thigh muscles, [latin capital V with dot above]o2peak and aerobic performance (Onset of Blood Lactate Accumulation [OBLA], respiratory exchange ratio [RER1]) during an incremental bicycle ergometer test. Four different on-ice tests were used to measure ice skating performance. For women, skating time was positively correlated (p < 0.05) to BW and negatively correlated to LBM%, PT/BW, OBLA, RER 1, and [latin capital V with dot above]o2peak (ml O2·kg-1 BW-1·min-1) in the Speed test. Acceleration test was positively correlated to BW and negatively correlated to OBLA and RER 1. For men, correlation analysis revealed only 1 significant correlation where skating time was positively correlated to [latin capital V with dot above]o2peak (L O2·min-1) in the Acceleration test. The male group had significantly higher physiological test values in all variables (absolute and relative to BW) but not in relation to LBM. Selected off-ice tests predict skating performance for women but not for men. The group of women was significantly smaller and had a lower physiological performance than the group of men and were slower in the on-ice performance tests. However, gender differences in off-ice variables were reduced or disappeared when values were related to LBM, indicating a similar capacity of producing strength and aerobic power in female and male hockey players. Skating performance in female hockey players may be improved by increasing thigh muscle strength, oxygen uptake, and relative muscle mass.
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| 9. |
- Shcherbina, Anna, et al.
(författare)
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Accuracy in wrist-worn, sensor-based measurements of heart rate and energy expenditure in a diverse cohort
- 2016
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: The ability to measure activity and physiology through wrist-worn devices provides an opportunity for cardiovascular medicine. However, the accuracy of commercial devices is largely unknown. Objective: To assess the accuracy of seven commercially available wrist-worn devices in estimating heart rate (HR) and energy expenditure (EE) and to propose a wearable sensor evaluation framework. Methods: We evaluated the Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, PulseOn, and Samsung Gear S2. Participants wore devices while being simultaneously assessed with continuous telemetry and indirect calorimetry while sitting, walking, running, and cycling. Sixty volunteers (29 male, 31 female, age 38 +/- 11 years) of diverse age, height, weight, skin tone, and fitness level were selected. Error in HR and EE was computed for each subject/device/activity combination. Results: Devices reported the lowest error for cycling and the highest for walking. Device error was higher for males, greater body mass index, darker skin tone, and walking. Six of the devices achieved a median error for HR below 5% during cycling. No device achieved an error in EE below 20 percent. The Apple Watch achieved the lowest overall error in both HR and EE, while the Samsung Gear S2 reported the highest. Conclusions: Most wrist-worn devices adequately measure HR in laboratory-based activities, but poorly estimate EE, suggesting caution in the use of EE measurements as part of health improvement programs. We propose reference standards for the validation of consumer health devices (http://precision.stanford.edu/).
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| 10. |
- Mattsson, C. Mikael
(författare)
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Requirements for Soldiers’ Endurance Capacity in Prolonged Continuous Work
- 2014
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Konferensbidrag (refereegranskat)abstract
- Physiological factors that influence soldier’s ability to sustain performance level in prolonged continuous work are such as A) initial physical level; B) ability to carry; and C) ability to sustain performance level over prolonged periods of time.A) General fitness level is obviously crucial, such as strength and aerobic capacity, but so is also being completely healthy when the effort initiates. We have presented an immunological profile that might be useful to determine which soldiers that will underperform. Before a 6-day military training course expression of CD3 on CD8+ lymphocytes and percent CD8+CD3 lymphocytes was lower, whereas CD4/CD8 ratio was higher among soldiers who failed compared to those who completed the training (Ekblom et al. 2011).B) It is well know that energy expenditure increases with increased carried weight, but at heavier loads (>30 kg) we found a disproportionate increase. Our hypothesis is that this is due to inaccurate technique, caused by insufficient strength relative to the carried weight, which may lead to unusual tiredness. In our preliminary results all soldiers had a point, carried weight, above which the work economy decreased. Therefore, it would be relevant to determine each soldier’s maximum optimal weight to carry.C) Fatigue and performance in ultra-endurance exercise, such as military efforts, is determined by (in part) other factors compared to traditional endurance sports. One of the most important aspects is energy balance. The total energy expenditure for a 24-h Adventure Race can be as high as 18-20 000 kcal (Enqvist et al. 2010). One reason for fatigue is the substantial energy deficit. Partly because that the profile of amino acids in blood and muscle change (Borgenvik et al. 2012), muscle damage (Wichardt et al. 2011), hormonal changes (Berg et al 2008), and immunological responses (Wallberg et al. 2011, Marklund et al. 2013). This combined indicates that specific supplementations may be needed. We have recently examined the energy balance in military situations. Two situations were 100 h, 78 km by foot in summer alpine terrain (6200 kcal/24h), and 187 h of mixed military tasks (5600 kcal/24h). Even though the allotment of rations was sufficient to cover the energy expenditure the actual intake was substantially lower, energy deficit being approximately 50 % and 33 %, respectively. However, we see large individual differences. If possible, energy availability should be individualized so that heavier soldiers and those with heavier tasks have opportunities to get higher energy supply compared to soldiers with lighter tasks and lower weight.
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