Changes in Player Activity Profiles After the 2015 FIH Rule Changes in Elite Women's Hockey.

McMahon, GE and Kennedy, RA. Changes in player activity profiles after the 2015 FIH rule changes in elite women's hockey. J Strength Cond Res 33(11): 3114-3122, 2019-The aim of this study was to compare the player activity profiles of elite international women's hockey players before (2014) and after (2015) the 2015 the International Hockey Federation (FIH) match rule changes at team and positional levels. The match activity profiles (n = 400) of 19 female hockey players (age 23 ± 4 years, mass 63.6 ± 5.5 kg, VO2max 57 ± 6 ml·kg·min in 2014, 58 ± 6 ml·kg·min in 2015) were recorded during competitive international matches in 2014 (match n = 12) and 2015 (match n = 13) using 10-Hz global positioning system units. The practical utility of an effect was only classified as substantial when there was a >75% likelihood that the ±90% confidence interval of the effect size (ES) was equal to or greater than the small (ES ± 0.2) reference value. Mean match time decreased by over 2 minutes from 71.72 ± 1.38 to 69.40 ± 4.72 minutes. There were increases at the team level in relative substitutions (SUB), relative distance (RD), high-speed running (HSR: 3.08-5.27 m·s), and surges (S), with a fall in low-speed running (LSR: 0-3.05 m·s) between 2014 and 2015. There were no changes in the between-position differences observed from 2014 to 2015. Within positions, there were relative increases in RD for all positions, HSR and S for midfield, and in SUB and S in forwards. The 2015 FIH rule changes seem to have increased the general intensity of international women's hockey. However, the different facets of physical performance did not change uniformly across team positions. Therefore, specific modifications to conditioning practices for each position may be warranted to more accurately reflect match demands.

La cafeína y su efecto ergogénico en el deporte (primera parte) / Caffeine and its ergogenic effect in sport (first part)

Los efectos de la cafeína sobre el organismo humano han sido estudiados desde hace tiempo y, a día de hoy, ya conocemos gran parte de sus características. En el mundo del deporte, la cafeína es una de las ayudas ergogénicas más populares y empleadas por entrenadores y atletas. Debido a su importancia, en este trabajo nos hemos propuesto el objetivo de analizar los efectos ergogénicos de la cafeína sobre el rendimiento deportivo y todo lo que rodea a esta acción, a través de una revisión de la literatura científica más actual. Hemos seleccionado aquellos estudios que incluyeran sujetos bien entrenados realizando una actividad física que reflejara las actuales prácticas en el deporte, prestando mucha atención a la metodología empleada, esto es la dosis, el momento y la forma de administración de la cafeína, para conseguir alcanzar nuestra meta de constituir una guía actualizada sobre todo lo que rodea a la cafeína como ayuda ergogénica en el deporte. Los resultados obtenidos nos han mostrado una gran variedad de estudios que han investigado acerca de la cafeína y el ejercicio físico siguiendo diferentes metodologías, lo que provoca una imposibilidad de generalizar sobre el asunto. Sin embargo, hemos podido extraer valiosas conclusiones como la clara tendencia hacia la efectividad de la cafeína como ayuda ergogénica en situaciones determinadas, nuevos hallazgos que tienen que ver con el uso de la cafeína en días consecutivos de actividad física, el mejor momento del día para el consumo de la sustancia o la administración estratégica de cafeína para contrarrestar la falta de sueño, y hacia dónde se dirigen las últimas tendencias en investigación dentro de la materia

The effects of caffeine on the human body have been studied for some time and much is now known about its characteristics. In the sports world, caffeine is one of the most popular ergogenic aids and is widely used by coaches and athletes. Given its importance, in this paper we analyze the ergogenic effects of caffeine on athletic performance and related actions, through a review of the latest scientific literature. We selected studies that included well-trained subjects performing a physical activity that reflects current practices in sport. Close attention was given to the methodology used, including the dose, timing and administration method of the caffeine, with the aim of establishing an updated guide to caffeine as an ergogenic aid in sport. The results show there are a variety of studies that have investigated the effects of caffeine on exercise using different methodologies, making it impossible to reach a general assumption. Nevertheless, we are able to draw valuable conclusions including the clear trend towards the effectiveness of caffeine as an ergogenic aid in certain situations, new findings that deal with the use of caffeine on consecutive days of physical activity, the best time of day to take the substance, the strategic management of caffeine to counteract sleep deprivation, and in what direction the latest research trends in this field are moving

Emergency department surveillance of injuries and head injuries associated with baseball, football, soccer and ice hockey, children and youth, ages 5 to 18 years, 2004 to 2014.

TITRE: Surveillance aux services d'urgence des blessures à la tête et de l'ensemble des blessures provoquées par le baseball, le football, le soccer ou le hockey sur glace chez les enfants et les jeunes de 5 à 18 ans, 2004 à 2014.

Serum Tau Fragments Predict Return to Play in Concussed Professional Ice Hockey Players.

The diagnosis of sports-related concussion is mainly based on subjective clinical symptoms and neuropsychological tests. Therefore, reliable brain injury biomarkers to assess when it is safe to return to play are highly desirable. The overall objective of this study was to evaluate the utility of two newly described tau fragments for diagnosis and prognosis of sports-related concussions. This multi-center prospective cohort study involved all 12 teams of the top professional ice hockey league in Sweden. A total of 288 players consented to participate in the study. Thirty-five players sustained concussions, of whom 28 underwent repeated blood samplings at 1, 12, 36, and 144 h after the trauma, or when the player returned to play (7 to >90 days). There was no significant increase in the levels of Tau-A in post-concussion samples compared with preseason values. However, serum levels of Tau-C were significantly higher in post-concussion samples compared with preseason. Further, levels of Tau-A correlated with the duration of post-concussive symptoms. Tau-A in serum, which is newly discovered biomarker, could be used to predict when it is safe to return to play after a sports-related concussion.

Ice hockey injuries among United States high school athletes from 2008/2009-2012/2013.

BACKGROUND: The popularity of ice hockey has grown in recent years and injuries are a concern given the physical nature of the sport. We sought to report the rates, mechanisms, and severity of boys' US high school ice hockey injuries. We hypothesized that body checking would be a major source of injury and that concussions would be common. We also expected to find that competition would have a higher rate of injury than practice. DESIGN: Descriptive epidemiology study. METHODS: Boys' US high school ice hockey injury data from 2008/2009 through 2012/2013 academic years were obtained from the National High School Sports-Related Injury Surveillance System, High School Reporting Information Online database. The primary outcome was rate of injury per 10,000 athlete exposures (AEs). RESULTS: Overall, 724 boys ice hockey injuries occurred during 311,817 AEs for an injury rate of 23.2 per 10,000 AEs. Injury rates were significantly higher during competition compared to practice (rate ratio = 7.8, 95% confidence interval: 6.5-9.4). Concussion was the most frequent injury reported at a rate of 6.4 per 10,000 AEs. Body checking was the mechanism of injury in over 46% of injuries. The head/face/neck region (33.8%) and upper arm/shoulder region (20.6%) were the most commonly injured body sites. Just over 6% of injuries resulted in surgical intervention. CONCLUSION: Injuries among high school ice hockey athletes are common. Increases in the number of high school ice hockey injuries will likely parallel the increase in high school ice hockey participation in the United States.

Does size of one's community affect likelihood of being drafted into the NHL? Analysis of 25 years of data.

The consistency of community size effects in North American contexts but not elsewhere, reinforces the notion that the effect is driven by socio-cultural factors specific to the country under examination. In order to identify and understand the various forces driving the community size effect, it is important to determine whether the effect has changed over time. Stability or instability over time would assist researchers in identifying the specific socio-cultural mechanisms driving these effects. This study compared the influence of community size on the likelihood of being drafted into the National Hockey League (NHL) among Canadian ice hockey players drafted to play in the NHL between 1985 and 2009. Although there was some variability over the timespan examined, most notably in communities with between 250,000 and 499,999 inhabitants and over 1,000,000 inhabitants, trends were generally stable over time, suggesting that the socio-cultural mechanisms may have also been relatively stable, although further work is necessary to confirm this assumption.

Secular trend: morphology and performance.

In a context of morphological expansion of the general population, how do athletes follow such a pattern of anthropometric growth? Is there any relation to performance? Biometric data including mass, height, body mass index (BMI) and age were collected for 50,376 American athletes representing 249,336 annual performers playing in professional baseball, football, ice hockey and basketball. Distributions by mass in National Football League (NFL) players are described by periods. Field goals have been studied in relation to players' height in the National Basketball Association (NBA). Between 1871 and 2011, athletes from the four sports have increased significantly in mass, height and BMI, following a multi-exponential function series. Consequently, biometric differences between athletes and the general population are increasing gradually. Changes in the mass distribution within the NFL show the emergence of a biometrical specificity in relation to the field position. At the professional level, performance remains structured around precise biometric values. In the NBA, a height-attractor at 201.3 ± 6.3 cm for the best scorers is invariant, regardless of the level of play. These results suggest that laws of growth and biometrics drive high-level sport and organise performance around the specific constraint of each field position. Discrepancies between some mass and height developments question the (disproportionate) large mass increase (relative to the height increase) during the 1980s and 1990s.

Subjective, but not objective, lingering effects of multiple past concussions in adolescents.

The existing literature on lingering effects from concussions in children and adolescents is limited and mixed, and there are no clear answers for patients, clinicians, researchers, or policy makers. The purpose of this study was to examine whether there are lingering effects of past concussions in adolescent athletes. Participants in this study included 643 competitive Bantam and Midget hockey players (most elite 20% by division of play) between 13 and 17 years of age (mean age=15.5, SD=1.2). Concussion history at baseline assessment was retrospectively documented using a pre-season questionnaire (PSQ), which was completed at home by parents and players in advance of baseline testing. Players with English as a second language, self-reported attention or learning disorders, a concussion within 6 months of baseline, or suspected invalid test profiles were excluded from these analyses. Demographically adjusted standard scores for the five composites/domains and raw symptom ratings from the brief Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) computerized battery were analyzed. Adolescent athletes with one or two or more prior concussions did not have significantly worse neurocognitive functioning on ImPACT than did those with no previous concussions. There were significantly more symptoms reported in those with two or more prior concussions than in those with no or one prior concussion. Adolescents with multiple previous concussions had higher levels of baseline symptoms, but there were not group differences in neurocognitive functioning using this brief computerized battery.

Effects of changing body-checking rules on rates of injury in minor hockey.

OBJECTIVE: In this study we explored the effects of the 2002 rule change in Ontario minor hockey, in which body-checking was introduced at the atom (ages 9-10) instead of the peewee (previously ages 12-13) age level. It was hypothesized that the introduction of body-checking at younger ages would result in higher overall rates of injury to minor hockey players, with concomitant increases in neurotraumatic injuries. PATIENTS AND METHODS: Participants included injured minor hockey players between the ages of 7 and 14 years in the Kingston area of Ontario, Canada. The Kingston sites of the Canadian Hospitals Injury Reporting and Prevention Program were used to identify injuries that presented to the only 2 emergency departments in this community. In our analyses, we compared rates and patterns of injury that required hospital-based emergency medicine care before (1997-1998 to 2001-2002 seasons) and after (2002-2003 to 2006-2007 seasons) implementation of the body-checking rule change. RESULTS: Overall rates of injury to minor hockey players declined in the years after the rule change. Rates of injury attributable to body-checking, as well as the natures and anatomic sites of injury caused by body-checking, remained consistent in the 2 study periods. CONCLUSIONS: In this historical study, we did not observe an increase in the overall rates of injury and concomitant neurotraumatic events. Increased enforcement of playing rules as well as temporal declines in emergency department use may have contributed to these findings.

Concussion incidence and time lost from play in the NHL during the past ten years.

BACKGROUND: The problem of concussions in professional hockey has attracted much recent attention. To evaluate the current state of this injury in the National Hockey League (NHL), we analyzed the concussion incidence and time lost from play due to concussions during the past ten NHL seasons. METHODS: Data were obtained from a complete review of injury reports in two different sports media sources covering the NHL seasons 1997-98 through 2007-08. Time lost from play was measured in missed games per concussion. RESULTS: The incidence of concussions reported in the regular season ranged from a high of 1.81/1000 athlete exposures in 1998-99 to a low of 1.04/1000 athlete exposures in 2005-06. There was a downward trend in the number of concussions reported per season during the past ten years (p=0.01). However, average time lost from play per concussion increased over the same period (p<0.0005). Forwards suffered a disproportionately high percentage of concussions (p<0.0001). CONCLUSIONS: Possibly related to injury reduction efforts, the number of concussions reported per season in the NHL has trended downward in recent years. However, the incidence of concussion remains high and the average time lost from play per concussion has increased. This may reflect increased injury severity in recent years or, alternatively, increased adherence to modern management guidelines preventing premature return to play.

Relative age and fast tracking of elite major junior ice hockey players.

Investigations in a variety of chronologically grouped team sports have reported that elite young athletes were more likely born in the early months of the selection year, a phenomenon known as the relative age effect. The present study investigated the birth dates and developmental paths of 238 (15 to 20 years old) Major Junior 'A' hockey players from the Ontario Hockey League to determine if a relative age effect still exists in elite junior hockey and if the path to elite sport was accelerated (i.e., fast tracked). The results identified a relative age effect in elite hockey although it is only apparent among individuals who fast track.

Developmental contexts and sporting success: birth date and birthplace effects in national hockey league draftees 2000-2005.

OBJECTIVES: To examine relative age and birth place effects in hockey players drafted to play in the National Hockey League (NHL) between 2000 and 2005 and determine whether these factors influenced when players were chosen in the draft. METHODS: 1013 North American draftees were evaluated from the official NHL website, which provided birthplace, date of birth and selection order in the draft. Population size was collected from Canadian and American census information. Athletes were divided into four quartiles on the basis of selection date to define age cohorts in hockey. Data between the Canadian and American players were also compared to see if the optimal city sizes differed between the two nations. RESULTS: Relative age and birthplace effects were found, although the optimal city size found was dissimilar to that found in previous studies. Further, there were inconsistencies between the Canadian and American data. CONCLUSION: Contextual factors such as relative age and size of birthplace have a significant effect on likelihood of being selected in the NHL draft.