159 research outputs found
Out-Of-Field Teaching by High School Science Teachers in the Wenatchee Valley
The purpose of this study was to heighten the awareness and draw attention to the level of out-of-field teachiug by high school science teachers in the Wenatchee Valley. This study was compared to the national average of out-of-field teachiug of science. High school science teachers from four school districts in the Wenatchee Valley were surveyed to determine the level of out-of-field teachiug. The results showed an increase in out-offield teachiug in the Wenatchee Valley compared to the national average. Recommendations were given to inform prospective science teachers about the necessary level of education needed to better prepare themselves for out-of-field teachiug
Repeated high-speed running in elite female soccer players during international competition
The purpose of the present study was to provide a detailed analysis of the repeated high-speed demands of competitive international female soccer match-play. A total of 148 individual match observations were undertaken on 107 outfield players in competitive international matches during the 2011-2012 and 2012-2013 seasons, using a computerized tracking system (STATS, Leeds, England). High-speed activity was classified as either sprint activity (SA) or high-speed running (HSR), with thresholds of >25.1 km.h-1 or >19.8 km.h-1 applied respectively. Repeated sprint activity (RSA) was defined as a minimum of two sprints with 20 s or less recovery between sprints and repeated high-speed activity (RHSA) was defined as a minimum of two high-speed runs or sprints with 20 s or less recovery between efforts. HSR bouts occurred ~5 times more frequently than SA bouts. Central defenders completed 50-80 fewer HSR bouts (moderate count ratio (CR): range 0.61-0.70) and 10-20 fewer SA bouts (moderate CR: range 0.53-0.69) than all other playing positions. RSA bouts occurred less frequently than RHSA bouts (33 ± 10 v 1.1 ± 1.1) with 37 % of players failing to complete any RSA bouts. Central defenders completed fewer RHSA bouts compared to all other playing positions (moderate CR: range 0.57-0.69). Consideration of both RHSA and RSA bouts is necessary to ensure a comprehensive understanding of the demands of female match-play. Practitioners can utilise this information to construct position-specific training and testing programmes which are aligned to the RHSA demands of match-play for elite female players
The Effects of Evening Bright Light Exposure on Subsequent Morning Exercise Performance
We investigated the effects of evening bright light on the circadian timing of core temperature and morning exercise performance under conditions of high thermal stress. At 20:00 h, 8 males were exposed to a standardised light protocol and thereafter to either polychromatic bright light (2 500 lux at 50 cm, BL) or no light (0 lux, NL) for 30 min. The following morning, intermittent cycling exercise was undertaken followed by a 10 km time-trial in an environmental chamber set to 35°C and 60% relative humidity. Core body temperature was measured throughout. Data were analysed using a within-subjects model and presented as mean±SD. Time of the sleep-trough in core temperature occurred ~1.75 h later following BL (P=0.07). Prior to time-trial, core temperature was 0.27±0.42°C lower in BL (95%CI: −0.02 to 0.57, P=0.07). The time-trial was completed 1.43±0.63 min (0.98–1.87) faster in BL (P=0.001). Post time-trial, intestinal temperature was 38.21±0.56°C (37.84–38.57) in BL compared to 38.64±0.42°C (38.34–38.93) in NL (P=0.10). These data provide the first evidence that a 30-min exposure to bright light prior to sleep can influence exercise performance under hot conditions during the subsequent early morning
Quantification of training and match-load distribution across a season in elite English Premier League soccer players
Objective: To examine training and match loads undertaken by soccer players competing in the English Premier League. Methods: Using a retrospective design, external (GPS) and internal training loads (sessions ratings of perceived exertion [sRPE-TL]) were examined in 26 players across the competition phase of the 2012–2013 English Premier League season. Within-subject linear mixed-models estimated the mean effects (95% confidence interval [CI]) for load data across 6-week mesocycles and 1-week microcycles. Results: Daily sRPE-TL (95% CI range, 15 to 111 AU) and total distance (95% CI range, 179 to 949 AU) were higher during the early stages (mesocycle 1 and 2) of the competition period. Overall, high-speed activity was similar between mesocycles. Across the training week, load was greater on match day and lower pre match-day (G-1) vs. all other days, respectively (p < 0.001). sRPE-TL (~70–90 AU per day) and total distance (~700–800 m per day) progressively declined over the 3 days before a match (p < 0.001). High-speed distance was greater 3 days (G-3) before a game vs. G-1 (95% CI, 140 to 336 m) while very high-speed distance was greater on G-3 and G-2 than G-1 (95% CI range, 8 to 62 m; p < 0.001). Conclusion: Periodisation of in-season training load is mainly evident across the weekly microcycle reflecting the recovery and preparation for matches.</p
Whole-body biomechanical load in running-based sports:the validity of estimating ground reaction forces from segmental accelerations
Applied physiology of female soccer: an update
The popularity and professionalism of female soccer has increased markedly in recent years, with elite players now employed on either a professional or semiprofessional 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 (>18 km·h-1). Elite players complete 28 % more high-speed running and 24 % more sprinting than moderate-level players. Decrements in highspeed 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
Exploring growth, maturity, and age as injury risk factors in high-level youth football
Rapid somatic growth and biological maturity status may affect injury patterns in youth football, yet firm conclusions cannot be drawn from the existing research. We aimed to explore growth velocity, maturity, and age as injury risk factors in 95 academy players (11.9-15.0 years), using anthropometric (height and body mass), maturity (skeletal age), injury, and football exposure data collected prospectively over three seasons (2016/17-2018/19). We compared the relative quality of mixed-effects logistic regression models with growth velocity for 223 growth intervals (average 113 days) included as fixed effects and adjusted for age (chronological or skeletal) plus load (hours/week). Associations were considered practically relevant based on the confidence interval for odds ratios, using thresholds of 0.90 and 1.11 to define small beneficial and harmful effects, respectively. We observed harmful effects of older age on overall (OR: 2.61, 95% CI: 1.15-5.91) and sudden onset (1.98, 1.17-3.37) injury risk. Significant associations (p<0.05) were observed for higher body mass change and greater maturity on sudden onset injuries, and for higher hours/week on gradual onset, bone tissue, and physis injuries. Future studies should include larger samples, monitoring athletes from pre-adolescence through maturation, to enable within-subject analyses and better understand the relationship between growth, maturation, and injuries
Monitoring Fatigue During the In-Season Competitive Phase in Elite Soccer Players.
Purpose:To quantify the relationship between daily training load and a range of potential measures of fatigue in elite soccer players during an in-season competitive phase (17 d).Methods:Total high-intensity-running (THIR) distance, perceived ratings of wellness (fatigue, muscle soreness, sleep quality), countermovement-jump height (CMJ), postexercise heart-rate recovery (HRR), and heart-rate variability (Ln rMSSD) were analyzed during an in-season competitive period (17 d). General linear models were used to evaluate the influence of daily fluctuation in THIR distance on potential fatigue variables.Results:Fluctuations in fatigue (r = −.51, large, P < .001), Ln rMSSD (r = −.24, small, P = .04), and CMJ (r = .23, small, P = .04) were significantly correlated with fluctuations in THIR distance. Correlations between variability in muscle soreness, sleep quality, and HRR and THIR distance were negligible and not statistically significant.Conclusions:Perceived ratings of fatigue and Ln rMSSD were sensitive to daily fluctuations in THIR distance in a sample of elite soccer players. Therefore, these particular markers show promise as simple, noninvasive assessments of fatigue status in elite soccer players during a short in-season competitive phase.</jats:sec
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