13 research outputs found

    Iron Supplementation Effects on Redox Status following Aseptic Skeletal Muscle Trauma in Adults and Children.

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    Exercise-induced skeletal muscle microtrauma is characterized by loss of muscle cell integrity, marked aseptic inflammatory response, and oxidative stress. We examined if iron supplementation would alter redox status after eccentric exercise. In a randomized, double blind crossover study, that was conducted in two cycles, healthy adults (n = 14) and children (n = 11) received daily either 37 mg of elemental iron or placebo for 3 weeks prior to and up to 72 h after an acute eccentric exercise bout. Blood was drawn at baseline, before exercise, and 72 h after exercise for the assessment of iron status, creatine kinase activity (CK), and redox status. Iron supplementation at rest increased iron concentration and transferrin saturation (p < 0.01). In adults, CK activity increased at 72 h after exercise, while no changes occurred in children. Iron supplementation increased TBARS at 72 h after exercise in both adults and children; no changes occurred under placebo condition. Eccentric exercise decreased bilirubin concentration at 72 h in all groups. Iron supplementation can alter redox responses after muscle-damaging exercise in both adults and children. This could be of great importance not only for healthy exercising individuals, but also in clinical conditions which are characterized by skeletal muscle injury and inflammation, yet iron supplementation is crucial for maintaining iron homeostasis. This study was registered at Clinicaltrials.gov Identifier: NCT02374619

    The effects of acute low-volume HIIT and aerobic exercise on leukocyte count and redox status

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    A single bout of exercise can result in inflammatory responses, increased oxidative stress and upregulation of enzymatic antioxidant mechanisms. Although low-volume high-intensity interval training (HIIT) has become popular, its acute responses on the above mechanisms have not been adequately studied. The present study evaluated the effects of HIIT on hematological profile and redox status compared with those following traditional continuous aerobic exercise (CET). Twelve healthy young men participated in a randomized crossover design under HIIT and CET. In HIIT session, participants performed four 30-sec sprints on a cycle-ergometer with 4 min of recovery against a resistance of 0.375 kg/kg of body mass. CET consisted of 30-min cycling on a cycle-ergometer at 70% of their VO2max. Blood was drawn at baseline, immediately post, 24h, 48h and 72h post-exercise and was analyzed for complete blood count and redox status (thiobarbituric acid reactive substances, [TBARS]; protein carbonyls, [PC]; total antioxidant capacity, [TAC]; catalase and uric acid). White blood cells (WBC) increased after both exercise protocols immediately post-exercise (HIIT: 50% and CET: 31%, respectively). HIIT increased (+22%) PC post-exercise compared to baseline and CET (p 0.05) for TBARS and catalase following either exercise protocol. Low-volume HIIT is associated with a greater acute phase leukocyte count and redox response than low-volume CET, and this should be considered when an exercise training program is developed and complete blood count is performed for health purposes

    Evaluating the Effects of Match-Induced Fatigue on Landing Ability; the Case of the Basketball Game

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    International Journal of Exercise Science 14(6): 768-778, 2021. This paper examines the effect of match–induced fatigue on lower limb biomechanics, in the case of a basketball game. For this purpose, sixteen male basketball athletes, ages 18 to 22, performed a jump-landing task prior and post a recreational basketball game. The Landing Error Scoring System (LESS) was used to examine the biomechanics of landing. The Vertical jump (VJ) and the Borg Rating of Perceived Exertion (RPE) scale pre- and post-game were employed to assess the level of fatigue induced by the basketball game. In order to compare pre and post measurements, t-tests for dependent samples were used. The performance of the VJ test post-game was found to be significantly lower (t (15) = 3.83, p = 0.002) showing a large effect (Cohen’s d = 0.9) compared to pre-game measurements. Further, the LESS scores were significantly (t (15) = 2.33, p = 0.034) higher post-game with a medium effect (d = 0.5). The differences in LESS scores were due to errors in the landing technique which is bound to be influenced by biomechanics. Moreover, the Borg RPE scale was found to be significantly higher (t (15) = 10.77, p \u3c 0.001) post-game showing a very large effect (d =2.6). It is important to note, that these significant differences occurred with a merely medium level of fatigue (6.6 ± 0.3 pre-game vs 11.9 ± 1.0 post-game). The results of this study would be of great benefit to sports science teams and coaches for formulating effective strategies to improve athletes’ performance and reduce the likelihood of injury

    The Effect of Ball Heading and Subclinical Concussion On the Neuromuscular Control Of The Lower Limb: A Systematic Review

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    # Background Soccer is unique among sports because it is the only sport that involves purposeful use of the head to control, pass, or shoot the ball. Over the previous five years, a relationship between lower extremity (LE) injury and sports related concussion (SRC) has been established in various sporting populations. Athletes at the high school, collegiate, and professional levels have demonstrated a greater risk for sustaining a LE injury post SRC. The purpose of this systematic review was to examine the relationship of the SRC with the incidence of LE injuries. # Methods Ten databases were searched with the following keywords: Lower limb, ball heading, neuromuscular control, concussion, MEDLINE, Ovid MEDLINE(R) Daily, and Ovid MEDLINE(R), EMBASE, and Scopus. The search was limited to English-language and peer-reviewed publications, until 15/12/2022. The PEDro scale was used for the assessment of the risk of bias among the included studies. All included papers were qualitatively analyzed. # Results A total of 834 studies were identified and 10 articles (four concussion-MSK biomechanics, six concussion-MSK injury) were included in the qualitative analyses. Included papers ranged from low to high quality. Due to the heterogeneous nature of the included study designs, quantitative meta-analysis was unable to be performed. All four of the included concussion-MSK biomechanics studies demonstrated, to some degree, that worse cognitive performance was associated with lower extremity MSK biomechanical patterns suggestive of greater risk for MSK injury. Among the six injury related studies, two investigations failed to determine group differences in cognitive performance between subsequently injured and non-injured athletes. # Conclusion More research is needed to better understand the relationship of SRC and lower extremity injuries and the extent to which they are related to concussions and/or repetitive neurotrauma after ball heading sustained in soccer. # Level of Evidence

    Investigation of the Impacts of Climate Variability and Land Use Changes on the Hydrology of the Geul River Catchment

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    The Geul river, a tributary of the Meuse located in the south Netherlands, Belgium, and part of Germany, is vulnerable to extreme hydrological events, such as floods, droughts, and erosion. There is evidence that these conditions are exacerbated by land use and climate changes. This thesis focuses on investigating the temporal variability and trends of hydrometeorological variables, as well as the main land use changes in the Geul river catchment. Accordingly, this thesis aims to improve understanding of the impacts of climate change and human intervention on the hydrological response of the Geul. In the first part of the thesis, temporal changes in (extreme) precipitation regimes for the period 1951-2021 and potential evaporation for the period 1965-2021, are identified by calculating trends for each 30-year moving period within the available time frames. The main land use changes are evaluated using CORINE annual land cover maps for the period 1990-2018. Changes in discharge regimes are investigated using a multi-temporal approach in which trends are evaluated in every possible combination of start and end years. In the second part of the thesis, the effects of climate variability and land use changes on the variability of runoff patterns are assessed. This is achieved by correlating the rates of change between extreme precipitation and maximum discharges all over the moving periods. The work also includes the use of a water balance separation framework to estimate the attribution of alterations in mean stream flows to land use and climate changes. A statistically significant increase in very wet days is reported in the area that mainly derives from the winter period. The extreme summer precipitationshows a relatively strong increase since the 1980s. The trend analysis in the potential evaporation time series suggests a very strong and stable increase. The main land use changes dominated before the 1970s, while there do not appear to be significant changes in the catchment from 1990 to 2018. Extreme annual discharges show an increasing insignificant tendency, while mean stream flows are decreasing. Results suggest that the variability of extreme and mean flows is mainly driven by climate variability, while at the same time the effects of land use changes on runoff patterns are not visible for the period 1970-2021. This study emphasizes that climate change should be incorporated into flood designs and climate adaptation strategies should be provided.Water Managemen

    The effects of a single bout of exercise on resting energy expenditure and respiratory exchange ratio.

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    We investigated the effects of a single bout of aerobic and resistance exercise of similar relative intensity and duration on resting energy expenditure (REE) and substrate utilisation. Ten young healthy males volunteered [age 22 (1.8) years, weight 76 (7.9) kg, height 176 (4.1) cm, percentage body fat 10.5 (4.0)%; mean (SEM)]. They randomly underwent three conditions in which they either lifted weights for 60 min at 70-75% of 1-RM (WL), ran for 60 min at 70-75% of maximal oxygen intake (R) or did not exercise (C). REE and substrate utilisation, determined via respiratory exchange ratio ( R), were measured prior to exercise, and 10, 24, 48 and 72 h post-exercise. It was revealed that REE was significantly elevated ( P<0.05) 10 and 24 h after the end of WL [2,124 (78) and 2,081 (76) kcal, respectively] compared to pre-exercise [1,972 (82) kcal]. REE was also significantly increased ( P<0.05) 10 and 48 h after the completion of R [2,150 (73) and 1,995 (74) kcal, respectively] compared to pre-exercise data [1,862 (70) kcal]. R was lower 10 and 24 h following either WL or R [0.813 (0.043); 0.843 (0.040) and 0.818 (0.021); 0.832 (0.021), respectively] compared to baseline measurements [0.870 (0.025) and 0.876 (0.04), respectively]. Creatine kinase was significantly elevated ( P<0.05) 24 h after both WL and R, whereas delayed onset muscle soreness became significantly elevated ( P<0.05) 24 h after only WL. There were no significant changes for any treatment in thyroid hormones (T(3) and T(4)). These results suggest that a single bout of either WL or R exercise, characterised by the same relative intensity and duration, increase REE and fat oxidation for at least 24 h post-exercise

    Race Pattern of Women’s 100-m Hurdles: Time Analysis of Olympic Hurdle Performance

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    Background: For control and effective management of training process in women’s 100-m hurdles event, the coaches, in addition to detailed biomechanical parameters, need also overall, more comprehensive technical parameters, called direct performance descriptors which are used for planning the distribution of an athlete’s efforts over the race. Purpose: The aim of this study was the investigation of the race behavior of elite women sprint hurdlers, on the basis of selected time parameters, and the examination of the existence of a common race pattern in high level hurdle performance. Method: The time data of the race performance between two consecutive Olympic Games were compared. The analyzing subjects consisted of all women 100-m hurdle finalists in Athens 2004 (n = 6) and all women 100-m hurdle finalists (n = 8) and semi-finalists (n = 14) in Beijing 2008. Results: No significant differences were revealed between the two competitions concerning to the means of approach run time, run-in time, intermediate touchdown times, interval times for the hurdle units and the corresponding average velocities. Significant relationship exists between the intermediate times and final performance. The time contribution of the first half of the race to the formation of the final performance is approximately equal to the second one and, generally the standardised time parameters show the existence of a common race pattern in high level hurdle performance. Conclusion: The presented biomechanical data provide coaches and athletes with valuable information about hurdle technique for effective interventions in the training process

    Race Pattern of Women’s 100-m Hurdles: Time Analysis of Olympic Hurdle Performance

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    Background: For control and effective management of training process in women’s 100-m hurdles event, the coaches, in addition to detailed biomechanical parameters, need also overall, more comprehensive technical parameters, called direct performance descriptors which are used for planning the distribution of an athlete’s efforts over the race. Purpose: The aim of this study was the investigation of the race behavior of elite women sprint hurdlers, on the basis of selected time parameters, and the examination of the existence of a common race pattern in high level hurdle performance. Method: The time data of the race performance between two consecutive Olympic Games were compared. The analyzing subjects consisted of all women 100-m hurdle finalists in Athens 2004 (n = 6) and all women 100-m hurdle finalists (n = 8) and semi-finalists (n = 14) in Beijing 2008. Results: No significant differences were revealed between the two competitions concerning to the means of approach run time, run-in time, intermediate touchdown times, interval times for the hurdle units and the corresponding average velocities. Significant relationship exists between the intermediate times and final performance. The time contribution of the first half of the race to the formation of the final performance is approximately equal to the second one and, generally the standardised time parameters show the existence of a common race pattern in high level hurdle performance. Conclusion: The presented biomechanical data provide coaches and athletes with valuable information about hurdle technique for effective interventions in the training process

    Mechanical and Contractile Properties of Knee Joint Muscles after Sports-Related Concussions in Women Footballers

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    The purpose of this study was to determine if women footballers have an increased lack of neuromuscular control of the knee joint after a concussion compared to a healthy cohort tested with tensiomyography (TMG). Forty-one female collegiate footballers were enrolled in this study from which there were 20 with a history of sports-related concussions (SRCs) and 21 control subjects. Results from the SRC group had significantly higher Tc (ms) (z = −5.478, p = 0.000) and significantly lower Dm (mm) (z = −3.835, p = 0.000) than the control group in the case of the rectus femoris muscle. The SRC group had significantly higher Tc (ms) (z = −2.348, p = 0.016) and significantly lower Dm (mm) (z = −4.776, p = 0.000) than the control group in the case of the vastus medialis muscle. The SRC group had significantly higher Tc (ms) (z = −5.400, p = 0.000) and significantly lower Dm (mm) (z = −4.971, p = 0.000) than the control group in the case of the vastus lateralis muscle. The SRC group had significantly higher Tc (ms) (z = −5.349, p = 0.000) than the control group in the case of the biceps femoris muscle response, whereas no significant difference was found in Dm (mm) (z = −0.198, p = 0.853) between the groups. The results of the current study may have implications for current practice standards regarding the evaluation and management of concussions and can add valuable information for knee prevention programs as well

    Streaming media as an alternative to direct student instruction for performing science experiments

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    In the present paper a comparison between the ideas of two groups of students, both of which were taught the same physics laboratory curriculum but using two different instruction approaches is presented. The experimental group was asked to watch some videos including the associated links to Physics theory explaining the phenomena to be observed, gather the information needed and then perform the experiments involved, while the control group followed the traditional lab teaching practice. The aim was (a) to investigate if it is feasible for students to watch a science experiment on a video clip, and then to construct and repeat in the science-lab what they have just watched on video, b) measure the extent to which students that follow this new instruction approach can achieve a similar level of understanding of the scientific topic addressed by the hands-on science experiment, as the students that were instructed how to conduct the school experiment in the traditional way. The final results of this dual educational trial are presented in this paper, while conclusions are presented and discussed
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