Parental Travel Behaviors and Children's Independent Mobility: A MultiSite Study.

PURPOSE: Children who are allowed greater independent mobility (IM) are more physically active. This study investigated associations between parents' current travel mode to work, their own IM and school travel mode as a child, and their child's IM. METHODS: Children in grades 4 to 6 (n = 1699) were recruited from urban, suburban, and rural schools in Vancouver, Ottawa, and Trois-Rivières. Parents reported their current travel mode to work, IM, and school travel mode as a child. Children self-reported their IM using Hillman's 6 mobility licenses. Multiple imputation was performed to replace missing data. Gender-stratified generalized linear mixed models were adjusted for child age, parent gender, urbanization, and socioeconomic status. RESULTS: The older a parent was allowed to travel alone as a child, the less IM their child had (boys: ß = -0.09, 95% confidence interval [CI], -0.13 to -0.04; girls: ß = -0.09, 95% CI, -0.13 to -0.06). Girls whose parents biked to work (ß = 0.45, 95% CI, 0.06-0.83) or lived in Trois-Rivières versus other sites (ß = 0.82, 95% CI, -0.43 to 1.21) had higher IM. IM increased with each year of age (boys: ß = 0.46, CI, 0.34-0.58; girls: ß = 0.38, 95% CI, 0.28-0.48). CONCLUSION: Parents who experienced IM later may be more restrictive of their child's IM. This may help explain the intergenerational decline in children's IM.

Developing an interprofessional decision support tool for diabetic foot ulcers management in primary care within the family medicine group model: a Delphi study in Canada.

BACKGROUND: Primary care professionals encounter difficulties coordinating the continuum of care between primary care providers and second-line specialists and adhere to practice guidelines pertaining to diabetic foot ulcers management. Family medicine groups are providing primary care services aimed to improve access, interdisciplinary care, coordination and quality of health services, and reduce emergency department visits. Most professionals working in family medicine groups are primary care physicians and registered nurses. The aim of this study was to develop and validate an interprofessional decision support tool to guide the management of diabetic foot ulcers for primary care professionals working within the family medicine group model. METHODS: A one-page decision tool developed by the research team was validated by an expert panel using a three-round Delphi protocol held between December 2019 and August 2021. The tool includes 43 individual actions and a care pathway from initial presentation to secondary prevention. Data collection was realized with both paper and electronic questionnaires, and answers were compiled in an electronic spreadsheet. Data was analyzed with use of descriptive statistics, and consensus for each item was defined as ≥ 80% agreement. RESULTS: Experts from 12 pre-identified professions of the diabetic foot ulcer interdisciplinary care team were included, 39 participants out of the 59 invited to first round (66.1%), 34 out of 39 for second (87.2%) and 22 out of 34 for third (64.7%) rounds. All items included in the final version of the decision support tool reached consensus and were deemed clear, relevant and feasible. One or more professionals were identified to be responsible for every action to be taken. CONCLUSIONS: This study provided a comprehensive decision support tool to guide primary care professionals in the management of diabetic foot ulcers. Implementation and evaluation in the clinical setting will need to be undertaken in the future.

Preservation of von Willebrand Factor Activity With the ModulHeart Device.

von Willebrand Factor (VWF) destruction is common with current heart pumps. This study evaluates VWF activity with ModulHeart, a novel device using 3 micropumps in parallel. In model 1, ModulHeart was compared with Impella devices in vitro. In model 2, 3 healthy swine received ModulHeart. Model 3 includes VWF data from patients who underwent protected percutaneous coronary intervention with ModulHeart. In models 1, 2, and 3, ModulHeart resulted in preservation of VWF, whereas there was a 27% and 19% reduction in VWF activity with the Impella CP and 5.0, respectively. ModulHeart features a unique design and demonstrated preservation of VWF activity.

Correlates of Physical Activity in Children from Families Speaking Non-official Languages at Home: a Multi-site Canadian Study.

BACKGROUND: Children from families speaking a non-official language at home may be particularly at risk for low physical activity (PA), underscoring a need to investigate correlates of PA in this subpopulation. METHODS: We recruited 478 children in 37 schools stratified by area-level socioeconomic status (SES) and type of urbanization within three regions of Canada. Steps/day were measured using SC-StepRx pedometers. We assessed potential social-ecological correlates with child and parent surveys. We used gender-stratified linear mixed models to examine the correlates of steps/day. RESULTS: Outdoor time was the strongest correlate of boys' and girls' PA. Lower area-level SES was associated with less PA among boys, but outdoor time attenuated this difference. The strength of association between outdoor time and PA decreased with age in boys and increased with age in girls. DISCUSSION: Outdoor time was the most consistent correlate of PA. Future interventions should promote outdoor time and address socioeconomic disparities.

Organ blood flow assessment with the ModulHeart cardiorenal support device.

BACKGROUND: ModulHeart (Puzzle Medical Devices Inc) is a novel percutaneous flow entrainment pump anchored in the descending aorta. The current study evaluates the hemodynamic effect of ModulHeart support and its impact on cerebral, myocardial, and renal blood flow. METHODS: ModulHeart was implanted in the descending aorta of four healthy calves. A ramp protocol (2000 RPM increments) was performed with the pump operating at five different speeds from 14 000 to 22 000 RPM. For each speed, pressures proximal and distal to the pump, and right heart catheterization measurements were recorded. Stable-isotope labeled microspheres were injected in the left ventricle to evaluate organ perfusion. RESULTS: Thermodilution cardiac output increased by 23% at 22 000 RPM. Greater pump speeds resulted in greater pump gradients, up to 10 mm Hg in mean arterial pressure at 22 000 RPM, without significant reduction of proximal perfusion pressures. Arterial pulse pressure remained stable at all speeds. ModulHeart was not associated with a reduction in cerebral or myocardial blood flow at any speed. Renal cortical and medullary blood flow increased by up to 50% and 40%, respectively. CONCLUSION: The ModulHeart device implanted in the descending aorta of healthy calves resulted in significant arterial pressure gradients and preserved pulse pressure. Greater pump speeds translated into greater increases in renal blood flow, with no decrease in cerebral or myocardial perfusion.

The science and art of testing in ice hockey: a systematic review of twenty years of research.

Introduction: Ice hockey is a complex sport requiring multiple athletic and technical attributes. Considering the variety of tests developed, on-ice testing protocols have been created to measure the physiological and mechanical attributes associated with performance. To our knowledge, a lack of technical resources exists to help stakeholders opt for on-ice protocols from among those developed. It becomes crucial for researchers and practitioners to select relevant and context-specific procedures. This systematic review of the literature outlines an inventory of the on-ice tests that have been used in the domain of ice hockey research over the last twenty years, and summarize protocols mostly used in major athletic components. Methods: A search was performed on three databases (PubMed, SPORTDiscus and Scopus) by following the PRISMA guidelines. Specific keywords were selected to find publications using on-ice testing protocols in the methodology. Four aspects of athletic attributes were used to categorize the protocols: aerobic capacity, acceleration-speed, agility-change of direction and ability to repeat skating sprints. Analyses were conducted regarding four categories of observations: population under study, on-ice reported test(s), outcomes measures and main findings. Results: A total of 107 articles were included, resulting in 55 on-ice tests related to the on-ice assessments of four major athletic components: aerobic capacity (n = 7), acceleration-speed (n = 6), agility and change of direction (n = 23) and repeated skating sprint ability (n = 19). Testing in male and older cohorts (≥16 years old) predominates, with a primary focus on the competitive amateur level. The selected tests were mainly designed for assessing on-ice physiological responses and fitness (n = 38), talent identification-team selection (n = 19), efficiency of interventions (n = 17) and validation purposes (n = 16). Conclusion: A prevalence of on-ice skating tests to assess the ability to repeat intense efforts, agility, acceleration and speed components exists, which are relevant and linked to match requirement. The wealth of on-ice tests used in the literature reflects the need to adapt the on-ice evaluation process to the population, constraints, and goals. This review is a valid toolbox and can benefit for researchers and practitioners interested in testing hockey players from different levels, with a variety of aims and needs, by helping them to select the relevant procedures to their environment and practice context.

Physical Activity, Occupational Stress, and Cardiovascular Risk Factors in Law Enforcement Officers: A Cross-sectional Study.

OBJECTIVE: This cross-sectional study aimed to assess the interrelationship between leisure-time physical activity (LTPA), occupational stress, and cardiovascular disease (CVD) risk factors in law enforcement officers (LEOs). METHODS: A total of 229 LEOs completed a survey assessing their LTPA level, occupational stress, and CVD risk factors. RESULTS: After adjusting for age and sex, physically inactive LEOs are more likely to have one or more CVD risk factors. While high occupational stress was associated with greater odds of CVD risk factors in physically inactive LEOs, stress was not significantly associated with the prevalence of CVD risk factors in active LEOs. CONCLUSIONS: Our results suggest that occupational stress is associated with the prevalence of CVD risk factors in LEOs. Nevertheless, LTPA might have the potential to mitigate the impact of occupational stress on CVD risk factors.

The Relative Age Effect in Ice Hockey: Analysis of Its Presence, Its Fading and of a Reversal Effect among Junior and Professional Leagues.

This study analyzes the relative age effect (RAE) among the world's best junior hockey leagues and in the NHL. Despite the prevalence of RAE in ice hockey, past research suggests its fading-reversal over time, which may occur at later stages of athletic development. The hypothesis of the RAE reversal was tested with two sources of raw data files from the 2021-2022 season: 15 of the best international junior and minor professional leagues (N = 7 399) and the NHL (N = 812). Birth quartile distributions were analyzed to verify the prevalence of RAE and quantile regression was used to test the reversal of RAE hypotheses. Advanced hockey metrics were aggregated from multiple data sources and used to compare early born with late born players using birth quartiles. Prevalence of the RAE was verified with crosstabs analyses and quantile regression was used to test the reversal effect. Results indicated that the RAE still prevailed in ice hockey, with higher magnitude in Canadian leagues. Regression analyses showed that late-born junior and minor pro players, despite getting less exposure in terms of games played, attained levels of offensive production similar to those of early born players. Late-born players able to emerge in the NHL performed similarly and sometimes displayed better performance (in some markers). Results suggest that stakeholders should find ways to pay special attention to late born players in talent identification processes and offer them opportunities to develop at the highest levels.

Change in heart rate variability during two firefighting work cycles.

This study aimed to determine whether the change in heart rate variability from pre to post firefighting is modulated by different work cycles. Thirteen male firefighters underwent two firefighting simulations that comprised two identical 25-min work bouts intercalated by a passive recovery period of either 20 min (T20) or 5 min (T5). The square root of the mean squared differences of successive R-R intervals (RMSSD) and aural temperature were measured at rest before (PRE) and after (POST) firefighting simulations. The decrease in RMSSD was different between firefighting simulations (T20: -10 ± 21.2 ms, T5: -19.9 ± 20.9 ms, interaction, p = 0.02). Post-firefighting aural temperature was greater (p = 0.05) in T5 (37.18 ± 0.53 °C) than in T20 (36.88 ± 0.49 °C). In conclusion, a shorter recovery period of 5 min between firefighting work bouts decreases post-firefighting heart rate variability, possibly attributed to a lower parasympathetic reactivation and a higher absolute value of body temperature.

Health, Safety, and Wellness Concerns Among Law Enforcement Officers: An Inductive Approach.

Background: Although studies have assessed the impact of occupational risk factors on the health of law enforcement officers (LEO's), few have involved (LEO's) as informants in ways that allow their points of view to be heard directly. Thus, the objective of this study is to explore the occupational health, safety, and wellness (OHSW) concerns of (LEO's). Methods: (LEO's) working in Quebec, Canada were invited to answer an open-ended question regarding their OHSW concerns. Using a multi-stage content analysis, the collected answers were analyzed and coded by two members of the research team to identify the most recurrent concerns of (LEO's). Findings: Five themes relating to the OHSW concerns of (LEO's) were identified, namely, the work schedule, occupational stress, work equipment, workplace health promotion, and operational risks. Furthermore, our analyses highlighted differences in the concerns of (LEO's) based on their level of experience and sex. Conclusions/Application to Practice: This study addresses a gap in the literature on the OHSW concerns from the perspective of (LEO's). Overall, our results support that the work schedule and occupational stress associated with law enforcement are the two most recurrent concerns of (LEO's). Thus, the results of this study further stress the need for police organizations to implement strategies and policies, which could mitigate the deleterious effects of these hazards on the overall wellness of (LEO's).

Cardiorespiratory Fitness of Police Recruits: Normative Reference Values and Temporal Trend.

ABSTRACT: Poirier, S, Houle, J, Lajoie, C, and Trudeau, F. Cardiorespiratory fitness of police recruits: normative reference values and temporal trend. J Strength Cond Res 37(1): 207-212, 2023-Several studies have highlighted the increased risk of cardiovascular diseases (CVDs) among police officers. Given the longitudinal association between cardiorespiratory fitness (CRF) in early adulthood and later appearance of CVD, the identification of police recruits exhibiting lower CRF could allow the implementation of targeted CVD prevention strategies. Unfortunately, norm-referenced values for the CRF of Canadian police recruits are not yet available. Thus, this research aimed to provide norm-referenced values for the CRF of police recruits in the province of Quebec (Canada) and to evaluate the temporal trend in the CRF of police recruits over a 14-year period. First, a model was developed to estimate maximal oxygen consumption (V̇O2max) based on the results of the physical ability test (PAT) used for the recruitment of police officers in Quebec. Based on the previously developed model, the CRF of police recruits who completed the PAT from 2004 to 2017 was retrospectively assessed using administrative records. The analysis of 7,234 PAT results including 2,150 females (29.7%) and 5,084 males (70.3%) suggests that police recruits generally present high levels of CRF with an average estimated V̇O2max of 53.3 ml·min-1·kg-1 for males and 43.8 ml·min-1·kg-1 for females. Furthermore, our analyses showed significant but small positive correlations between estimated V̇O2max and time periods of PAT performance for male (rs = 0.105, p < 0.001) and female recruits (rs = 0.125, p < 0.001). Overall, our results suggest that the CRF of police recruits in Quebec is considerably higher than that of their North American peers.

Needs and interests regarding the lifestyle habits of students in a Canadian university.

OBJECTIVE: In this study, we investigate university students to learn about their barriers to improving and/or maintaining a healthy lifestyle and their needs and interests regarding the development of a tailored intervention to promote physical activity and a healthy diet. PARTICIPANTS: The qualitative research included three focus groups consisting of 22 university students.Methods: The interview grid was developed around the variables of the ecological Conceptual Framework of the Quebec Ministry of Health and Social Services. Data were analyzed using NVivo software.Results: Time constraints due to a heavy workload, high costs and low motivation were the reasons students failed to participate in physical activity and/or adopt a healthy diet. Furthermore, they perceived that on-campus food and physical activity are more expensive and the quality of food is poorer.Conclusions: Students are nevertheless interested in the development of a tailored intervention to promote physical activity and a healthy diet.

Correlates of Outdoor Time in Schoolchildren From Families Speaking Nonofficial Languages at Home: A Multisite Canadian Study.

BACKGROUND: Previous research shows that children from ethnic minority groups spend less time outdoors. Using data collected in 3 regions of Canada, we investigated the correlates of outdoor time among schoolchildren who spoke a nonofficial language at home. METHODS: A total of 1699 children were recruited from 37 schools stratified by area-level socioeconomic status and type of urbanization. Among these, 478 spoke a nonofficial language at home. Children's outdoor time and data on potential correlates were collected via questionnaires. Gender-stratified linear multiple regression models examined the correlates of outdoor time while controlling for age and sampling variables. RESULTS: In boys, higher independent mobility, higher outdoor air temperature, mobile phone ownership, having older parents, and parents who biked to work were associated with more outdoor time. Boys living in suburban (vs urban) areas spent less time outdoors. The association between independent mobility and outdoor time became weaker with increasing age for boys. In girls, lower parental education and greater parental concerns about neighborhood safety and social cohesion were associated with less outdoor time. CONCLUSIONS: Correlates of outdoor time differ by gender and span the social ecological model underscoring the need for gender-sensitized interventions targeted at individual, family, social, and physical environmental correlates to increase outdoor time.

Physical Activity Participation in People With an Active Diabetic Foot Ulceration: A Scoping Review.

BACKGROUND: Being physically active on a regular basis has a favourable impact on diabetes-related complications. With the exception of evidence advising individuals with an active diabetic foot ulceration (DFU) to avoid weight-bearing activity, no physical activity (PA) recommendations are currently provided for this population. OBJECTIVE: The aim of this scoping review was to examine and map the existing research evidence of PA participation for individuals with an active DFU. DESIGN: A scoping review using the Arksey and O'Malley framework was conducted in electronic databases and grey literature from inception to June 2020 to identify publications that investigated individuals with type 1 or type 2 diabetes and an active DFU at enrolment in relation to a PA intervention. Reported outcomes had to inform on effects of PA on any health or wound parameters. RESULTS: Nineteen articles from 17 distinct studies met inclusion criteria. Fourteen of the included studies were published in the last 10 years. Types of exercises and materials used, duration of studies, offloading considerations and provision of wound care varied greatly between studies. Included studies are heterogenous in methodological designs and aims, and reporting was often lacking important components of wound care and PA interventions. A discussion based on descriptive statistics and narrative analysis is provided. CONCLUSIONS: It is not possible from this scoping review to determine what would be the ideal components of a PA program for this specific population. Conclusions are limited by the quality and design of the included studies. No articles evaluated quality of life, mortality or cardiorespiratory capacity, nor were adverse effects routinely reported.

Cardiorespiratory fitness in police recruits: Assessing the validity of the 20-meter shuttle run test for recruitment purposes.

BACKGROUND: Although the 20-meter shuttle run test (20MSR) is frequently used by police organisations for recruitment purposes, to our knowledge no study has yet assessed the accuracy of this test to estimate maximal oxygen consumption (VO2max) in police recruits. OBJECTIVE: The primary objective of this study was to assess the validity of the 20MSR as a predictor of VO2max in police cadets. METHODS: 49 police cadets completed both an indirect calorimetry VO2max assessment and a 20MSR. Based on their results, estimated VO2max was calculated using an established equation. Furthermore, two models estimating the VO2max was also developed using the final stage completed and sex as independent variables in the first model (model A) as well as the final half-stage completed and sex in the second model (model B). RESULTS: A strong and significant bivariate correlation was found between measured VO2max and the final stage completed at the 20MSR (r = 0.874, p < 0.001). Nevertheless, limits of agreement analysis showed relatively large agreement errors between measured VO2max and estimated VO2max based on the established equation (0.46±6.29 ml·min-1·kg-1), model A (0.00±5.58 ml min-1 kg-1), and model B (0.00±5.48 ml min-1·kg-1). CONCLUSIONS: Although the 20MSR can be a useful tool to estimate cardiorespiratory fitness for research and conditioning purposes, the large agreement errors found in this study suggest that results at the 20MSR should be interpreted with caution when making "pass or fail" decisions.

Postexercise hypotensive response in stroke patients following acute moderate or high intensity cycling session.

BACKGROUND: Hypertension is highly prevalent in stroke patients and reducing blood pressure is a priority. Aerobic exercise is known to induce postexercise hypotensive responses, but limited studies have documented this concept in stroke patients. The purpose was to investigate the effect of a single bout of moderate intensity continuous training (MICT) and high-intensity interval training (HIIT) on postexercise ambulatory blood pressure with patients with prior ischemic stroke or transient ischemic attack (TIA). METHODS: Ten hypertensive adults (mean age: 70±9 years) with prior ischemic stroke or TIA participated using a randomized crossover design. Ambulatory blood pressure was monitored for up to 8 hours after either ergocycle MICT or HIIT of respectively 50% and 95% of peak power output. Blood pressure was compared to pre-exercise resting measure. RESULTS: HIIT and MICT induced a decrease of systolic blood pressure of -11.0±9.2 mmHg and -4.7±4.5 mmHg respectively (P=0.03) immediately after the exercise. Ambulatory systolic blood pressure showed a steady linear increase (R2=0.90; P<0.001) of ~1.2 mmHg/hour and returned to pre-exercise measure after 8 hours. Effect of the two exercise conditions over time did not significantly differ (P=0.278). Diastolic blood pressure was not affected by both exercises. CONCLUSIONS: Those results suggest that HIIT induce a systolic blood pressure reduction of greater magnitude than MICT immediately after cycling exercise among patients with prior ischemic stroke or TIA. For both exercises, effects on ambulatory blood pressure are similar and persist up to 8 hours.

Associations Between School Environments, Policies and Practices and Children's Physical Activity and Active Transportation.

BACKGROUND: There is evidence of school-level variability in children's active behaviors. This study investigated the associations between school environments, policies and practices, and children's physical activity (PA) and active school transportation (AST), in a school ecology context. METHODS: We recruited children (N = 1699, age = 10.2 ± 1.0 years, 55.0% girls) in 37 schools from 3 diverse regions of Canada. We then collected data using questionnaires (child, parent) and pedometers. In each school, an official completed a School Health Environment Survey. Multilevel regression models were used to examine associations with children's daily steps, and frequency and volume (frequency*distance) of AST. RESULTS: Between-school variation ranged from 4.7% to 22.2% demonstrating that school environments are associated with children's active behaviors. None of the school environment variables were significantly associated with children's PA or frequency of AST. Nevertheless, their inclusion improved the PA model. Children's volume of AST increased in schools that reported more initiatives to promote AST. CONCLUSIONS: Our findings suggest that multiple components are needed to effectively promote active behaviors in children. Schools should determine the areas in which they can improve and assess the feasibility of implementing measures to make their school environments, policies, and practices more conducive to PA and AST.

Addition of high-intensity interval training to a moderate intensity continuous training cardiovascular rehabilitation program after ischemic cerebrovascular disease: A randomized controlled trial.

Introduction: Moderate intensity continuous training (MICT) is usually recommended for stroke or transient ischemic attack (TIA) patients. High intensity interval training (HIIT) has emerged as a potentially effective method for increasing cardiorespiratory fitness (CRF) among clinical populations. Its effectiveness remains to be demonstrated after stroke. A combined program of HIIT and MICT was designed to create a realistic exercise program implemented for a clinical setting to help patients become more active. Purpose: This study aimed to compare the effects of a 6-month exercise program with either MICT only or a combination of HIIT and MICT and a control group in terms of CRF, cardiovascular risk factors, functionality, cognitive function (Montreal Cognitive Assessment) and depression markers (Hospital Anxiety and Depression Scale). Methods: This randomized controlled trial started with 52 participants (33 men and 19 women, mean age: 69.2 ± 10.7) divided into three groups: HIIT + MICT combined, MICT, and control. Both exercise groups consisted of 4 weekly sessions including supervised and at-home exercise. Outcomes were assessed at T0 (baseline measure), T6 (end of exercise protocols), and T12 (follow-up), 40 participants having completed the 12-month follow-up. Results: At T6, both HIIT+MICT and MICT programs provided a similar increase of CRF (3 ml·min-1·kg-1) from baseline (p < 0.01), while the control group showed a global slight decrease. Despite some decrease of CRF at T12 compared to T6, improvement persisted 6 months post-intervention (HIIT + MICT: p < 0.01 and MICT: p < 0.05). The control group decreased compared with baseline (p < 0.05). The two exercise programs induced a comparable increase in self-reported physical activity and a decrease in anxiety and depression markers. Participants in HIIT + MICT and MICT programs declared a good degree of acceptability assessed by the Acceptability and Preferences Questionnaire. Conclusion: A 6-month HIIT + MICT combined program and a standard MICT program induced similar improvements in CRF, self-reported physical activity and anxiety and depression markers among patients with prior ischemic stroke or TIA compared with a control group. These effects appear to persist over time. Addition of HIIT was safe and considered acceptable by participants. Our results do not support any superiority of the combination HIIT + MICT nor disadvantage vs. MICT in this population.

Normative values of resting heart rate variability in young male contact sport athletes: Reference values for the assessment and treatment of concussion.

Objective: The objective of this study was to identify the main determinants of heart rate variability (HRV) in male athletes aged 14 to 21 years who practice competitive contact sports and to integrate these determinants with the aim of defining normative values of short-term HRV in the time and frequency domains. Methods: Participants (n = 369) were aged 14 to 21 years and included 221 football players and 148 ice hockey players. HRV was measured for 5 min at rest, and standard HRV parameters in the time and frequency domains were calculated. Heart rate (HR), age, body mass index (BMI), number of sports weekly practices (WSP) and concussion history (mTBI) were considered determinants potentially able to influence HRV. Results: Multiple regression analysis revealed that HR was the primary determinant of standard HRV parameters. The models accounted for 13% to 55% of the total variance of HRV and the contribution of HR to this model was the strongest (ß ranged from -0.34 to -0.75). HR was the only determinant that significantly contributes to all HRV parameters. To counteract this dependence, we calculated HRV corrected by the mean RR interval (RRm). Such corrections do not remove any physiological differences in HRV; they simply remove the mathematical bias. HRV parameters were therefore normalized, and their normative limits were developed relative to the mean heart rate. After correction, the correlation coefficients between HR and all corrected HRV parameters were not statistically significant and ranged from -0.001 to 0.045 (p > 0.40 for all). The automatically corrected HRV calculator, which recalculates standard HRV parameters and converts them into corrected parameters in addition to determining whether a given value is within normal limits, facilitates clinical interpretation. Conclusion: This study provides for the first time corrected normative values of short-term and resting state HRV parameters in competitive contact sport athletes aged 14 to 21 years. These values were developed independently of the major determinants of HRV. The baseline values for HRV parameters given here could be used in clinical practice when assessing and monitoring cerebral concussions. They may assist in decision making for a safe return to play.

Relative Age Effect in Canadian Hockey: Prevalence, Perceived Competence and Performance.

The term "relative age effect" (RAE) is used to describe a bias in which participation in sports (and other fields) is higher among people who were born at the beginning of the relevant selection period than would be expected from the distribution of births. In sports, RAEs may affect the psychological experience of players as well as their performance. This article presents 2 studies. Study 1 aims to verify the prevalence of RAEs in minor hockey and test its associations with players' physical self-concept and attitudes toward physical activities in general. Study 2 verifies the prevalence of the RAE and analyzes the performance of Canadian junior elite players as a function of their birth quartile. In study 1, the sample is drawn from 404 minor hockey players who have evolved from a recreational to an elite level. Physical self-concept and attitudes toward different kinds of physical activities were assessed via questionnaires. Results showed that the RAE is prevalent in minor hockey at all competition levels. Minor differences in favor of Q1-born players were observed regarding physical self-concept, but not attitudes. In study 2, data analyses were conducted from the 2018-2019 Canadian Hockey League database. Birth quartiles were compared on different components of performance by using quantile regression on each variable. Results revealed that RAEs are prevalent in the CHL, with Q1 players tending to outperform Q4 players in games played and power-play points. No other significant differences were observed regarding anthropometric measures and other performance outcomes. RAEs are still prevalent in Canadian hockey. Building up perceived competence and providing game-time exposure are examples of aspects that need to be addressed when trying to minimize RAEs in ice hockey.