Inflammatory pathway communication with skeletal muscle-Does aging play a role? A topical review of the current evidence.

Skeletal muscle plays an integral role in locomotion, but also as part of the integrative physiological system. Recent progress has identified crosstalk between skeletal muscle and various physiological systems, including the immune system. Both the musculoskeletal and immune systems are impacted by aging. Increased age is associated with decreased muscle mass and function, while the immune system undergoes "inflammaging" and immunosenescence. Exercise is identified as a preventative medicine that can mitigate loss of function for both systems. This review summarizes: (1) the inflammatory pathways active in skeletal muscle; and (2) the inflammatory and skeletal muscle response to unaccustomed exercise in younger and older adults. Compared to younger adults, it appears older individuals have a muted pro-inflammatory response and elevated anti-inflammatory response to exercise. This important difference could contribute to decreased regeneration and recovery following unaccustomed exercise in older adults, as well as in chronic disease. The current research provides specific information on the role inflammation plays in altering skeletal muscle form and function, and adaptation to exercise; however, the pursuit of more knowledge in this area will delineate specific interventions that may enhance skeletal muscle recovery and promote resiliency in this tissue particularly with aging.

Identifying the Cerebral Physiologic Response to Aerobic Exercise Following Concussion: A Scoping Review.

OBJECTIVE: The purpose of this study was to identify the cerebral physiologic response to aerobic exercise in individuals with a symptomatic concussion, highlighting available knowledge and knowledge gaps in the literature. DESIGN: A systematic scoping review was conducted and reported in keeping with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. A search of EMBASE, MEDLINE, SCOPUS, BIOSIS, and Cochrane libraries was conducted on June 15, 2023 (from database inception). An online systematic/scoping review management system was used to remove duplicates, and the remaining articles were screened for inclusion by 2 researchers. Inclusion criteria required articles to be original research published in peer-reviewed journals. Additionally, studies were required to have an aerobic exercise component, include a measure of cerebral physiology during a bout of aerobic exercise, exclude moderate and/or severe traumatic brain injury (TBI) populations, and be in the English language. Both human and animal studies were included, with participants of any age who were diagnosed with a mild TBI/concussion only (ie, Glasgow Coma Scale score ≥ 13). Studies could be of any design as long as a measure of cerebral physiologic response to a bout of aerobic exercise was included. RESULTS: The search resulted in 1773 articles to be screened and data from 3 eligible studies were extracted. CONCLUSIONS: There are currently too few studies investigating the cerebral physiologic response to aerobic exercise following concussion or mild TBI to draw definitive conclusions. Further research on this topic is necessary since understanding the cerebral physiologic response to aerobic exercise in the concussion and mild TBI populations could assist in optimizing exercise-based treatment prescription and identifying other targeted therapies.

Efficacy of aerobic exercise following concussion: a narrative review.

Concussion is a type of mild traumatic brain injury which results in symptoms within the physical, cognitive, emotional, and sleep domains. Historically, guidelines established by expert opinion have recommended rest during the initial stages of recovery following a concussion until symptom resolution. However, recent recommendations have shifted to advise an initial period of 24-48 h of rest immediately following concussion with the gradual introduction of light-to-moderate intensity aerobic exercise thereafter. Given the relatively recent transition in recommendations, the aim of this review is to provide an overview of the current literature on the efficacy of aerobic exercise following concussion. The current literature is limited to studies assessing the impact of standardized aerobic exercise following concussion. Upon review, literature suggests participating in aerobic exercise below the point of symptom exacerbation is safe in both the acute and chronic post-concussion symptom stages of recovery and does not delay time to medical clearance. Future large-scale randomized controlled trials assessing the impact of aerobic exercise and differences between males and females would help support the current evidence suggesting aerobic exercise could improve time to recovery following concussion and identify any sex differences in response. As well, future studies with the purpose of identifying optimal aerobic exercise volume and intensity in the treatment of concussion could improve the specificity of the current guidelines.

The Quantitative Associations Between Near Infrared Spectroscopic Cerebrovascular Metrics and Cerebral Blood Flow: A Scoping Review of the Human and Animal Literature.

Cerebral blood flow (CBF) is an important physiologic parameter that is vital for proper cerebral function and recovery. Current widely accepted methods of measuring CBF are cumbersome, invasive, or have poor spatial or temporal resolution. Near infrared spectroscopy (NIRS) based measures of cerebrovascular physiology may provide a means of non-invasively, topographically, and continuously measuring CBF. We performed a systematically conducted scoping review of the available literature examining the quantitative relationship between NIRS-based cerebrovascular metrics and CBF. We found that continuous-wave NIRS (CW-NIRS) was the most examined modality with dynamic contrast enhanced NIRS (DCE-NIRS) being the next most common. Fewer studies assessed diffuse correlation spectroscopy (DCS) and frequency resolved NIRS (FR-NIRS). We did not find studies examining the relationship between time-resolved NIRS (TR-NIRS) based metrics and CBF. Studies were most frequently conducted in humans and animal studies mostly utilized large animal models. The identified studies almost exclusively used a Pearson correlation analysis. Much of the literature supported a positive linear relationship between changes in CW-NIRS based metrics, particularly regional cerebral oxygen saturation (rSO2), and changes in CBF. Linear relationships were also identified between other NIRS based modalities and CBF, however, further validation is needed.

Omega-3 Fatty Acids for the Management of Osteoarthritis: A Narrative Review.

Osteoarthritis (OA) is a disease which results in degeneration of cartilage within joints and affects approximately 13.6% of adults over 20 years of age in Canada and the United States of America. OA is characterized by a state of low-grade inflammation which leads to a greater state of cellular catabolism disrupting the homeostasis of cartilage synthesis and degradation. Omega-3 polyunsaturated fatty acids (PUFAs) have been postulated as a potential therapeutic treatment option for individuals with OA. Omega-3 PUFAs are recognized for their anti-inflammatory properties, which could be beneficial in the context of OA to moderate pro-inflammatory markers and cartilage loss. The purpose of this narrative review is to outline recent pre-clinical and clinical evidence for the use of omega-3 in the management of OA.

Effects of Omega-3 Supplementation Alone and Combined with Resistance Exercise on Skeletal Muscle in Older Adults: A Systematic Review and Meta-Analysis.

Sarcopenia negatively affects skeletal muscle mass and function in older adults. Omega-3 (ω-3) fatty acid supplementation, with or without resistance exercise training (RET), is suggested to play a role as a therapeutic component to prevent or treat the negative effects of sarcopenia. A systematic review and meta-analysis were conducted on the impact of ω-3 fatty acid supplementation with or without RET on measures of muscle mass and function in older adults (≥55 y). The data sources included SPORTDiscus, PubMed, and Medline. All the study types involving ω-3 fatty acid supplementation on measures of muscle mass and function in older adults (without disease) were included. The mean differences (MDs) or standardized mean differences (SMDs) with 95% confidence intervals were calculated and pooled effects assessed. Sixteen studies (1660 females, 778 males) met our inclusion criteria and were included in the meta-analysis. ω-3 fatty acid supplementation did not impact lean tissue mass (SMD 0.09 [-0.10, 0.28]). Benefits were observed for lower body strength (SMD 0.54 [0.33, 0.75]), timed-up-and-go (MD 0.29 [0.23, 0.35]s), and 30-s sit-to-stand performance (MD 1.93 [1.59, 2.26] repetitions) but not walking performance (SMD -0.01 [-0.10, 0.07]) or upper body strength (SMD 0.05 [-0.04, 0.13]). Supplementing with ω-3 fatty acids may improve the lower-body strength and functionality in older adults.

Non-Invasive and Minimally-Invasive Cerebral Autoregulation Assessment: A Narrative Review of Techniques and Implications for Clinical Research.

The process of cerebral vessels regulating constant cerebral blood flow over a wide range of systemic arterial pressures is termed cerebral autoregulation (CA). Static and dynamic autoregulation are two types of CA measurement techniques, with the main difference between these measures relating to the time scale used. Static autoregulation looks at the long-term change in blood pressures, while dynamic autoregulation looks at the immediate change. Techniques that provide regularly updating measures are referred to as continuous, whereas intermittent techniques take a single at point in time. However, a technique being continuous or intermittent is not implied by if the technique measures autoregulation statically or dynamically. This narrative review outlines technical aspects of non-invasive and minimally-invasive modalities along with providing details on the non-invasive and minimally-invasive measurement techniques used for CA assessment. These non-invasive techniques include neuroimaging methods, transcranial Doppler, and near-infrared spectroscopy while the minimally-invasive techniques include positron emission tomography along with magnetic resonance imaging and radiography methods. Further, the advantages and limitations are discussed along with how these methods are used to assess CA. At the end, the clinical considerations regarding these various techniques are highlighted.

Anti-Inflammatory and Anti-Catabolic Effects of Creatine Supplementation: A Brief Review.

It is well established that creatine supplementation, primarily when combined with resistance training, significantly increases measures of muscle mass and performance (primarily strength). Emerging research also indicates that creatine supplementation may have favorable effects on measures of bone biology. These anabolic adaptations may be related to creatine influencing cellular hydration status, high-energy phosphate metabolism, growth factors, muscle protein kinetics, and the bone remodeling process. Accumulating research also suggests that creatine supplementation has anti-inflammatory and anti-catabolic properties, which may help create a favorable environment for muscle and bone accretion and recovery from exercise. Creatine supplementation has the ability to decrease markers of inflammation and possibly attenuate cancerous tumor growth progression. From a musculoskeletal perspective, there is some evidence to show that creatine supplementation reduces measures of muscle protein catabolism (primarily in males) and bone resorption when combined with resistance training. The purpose of this brief review is to summarize the current body of literature examining the potential anti-inflammatory and anti-catabolic effects of creatine supplementation across various research populations.

Effects of Creatine Supplementation on Brain Function and Health.

While the vast majority of research involving creatine supplementation has focused on skeletal muscle, there is a small body of accumulating research that has focused on creatine and the brain. Preliminary studies indicate that creatine supplementation (and guanidinoacetic acid; GAA) has the ability to increase brain creatine content in humans. Furthermore, creatine has shown some promise for attenuating symptoms of concussion, mild traumatic brain injury and depression but its effect on neurodegenerative diseases appears to be lacking. The purpose of this narrative review is to summarize the current body of research pertaining to creatine supplementation on total creatine and phophorylcreatine (PCr) content, explore GAA as an alternative or adjunct to creatine supplementation on brain creatine uptake, assess the impact of creatine on cognition with a focus on sleep deprivation, discuss the effects of creatine supplementation on a variety of neurological and mental health conditions, and outline recent advances on creatine supplementation as a neuroprotective supplement following traumatic brain injury or concussion.

Benign Paroxysmal Positional Vertigo After Pediatric Sports-Related Concussion.

OBJECTIVE: Report the clinical findings and outcomes among pediatric patients diagnosed with benign paroxysmal positional vertigo (BPPV) after sports-related concussion (SRC). DESIGN: Retrospective case series. SETTING: Multidisciplinary pediatric concussion program. PATIENTS: Patients younger than 19 years with a sport or recreation activity-related concussion referred for comprehensive vestibular physiotherapy assessment. MAIN OUTCOME MEASURE: Symptom resolution after targeted particle repositioning (PR). RESULTS: During the study period, 115 pediatric SRC patients underwent vestibular physiotherapy assessment including 12 (10.4%) who were diagnosed with BPPV. Unilateral posterior semicircular canal (SCC) BPPV was diagnosed in 8/12 (75%) patients, and unilateral anterior SCC BPPV diagnosed in 4/12 (25%) patients. Benign paroxysmal positional vertigo was successfully treated in all patients with a mean of 1.58 targeted PR maneuvers (range = 1-4). CONCLUSIONS: Comprehensive management of pediatric SRC requires a multidisciplinary approach to address the heterogeneous pathophysiology of persistent postconcussion symptoms. Pediatric SRC patients with coexisting BPPV should be considered for targeted PR.

The Effects of Acute Anaerobic Exercise on the Cardiovascular and Metabolic Response to the Cold Pressor Test in Healthy Adult Males.

Little is known about the physiological response to the cold pressor test (CPT) when in a clinically-induced state of autonomic nervous system (ANS) imbalance, despite its utility in various disease- and injury-states. To date, research in this area is limited to acute aerobic and isometric exercise, with a paucity of research investigating the effects of anaerobic exercise on the physiological response to the CPT. Therefore, the purpose of our study was to assess the effects of the Wingate anaerobic cycle test (WAT) on cardiovascular (CV) and metabolic recovery following the CPT in a group of healthy adult males. A pre-post intervention study was conducted, whereby 10 healthy adult males (age = 29 ± 4 years, height = 182 ± 7 cm, mass = 83 ± 9 kg) completed a baseline cold pressor test (CPT-only) and a follow-up cold pressor test preceded by a Wingate anaerobic exercise test (WAT+CPT). Recovery slopes for various CV and metabolic variables, including heart rate (HR), blood pressure (BP), and relative oxygen consumption (V̇O2) were analyzed using single-subject analysis, with celeration line slopes calculated for all participants in the CPT-only and WAT+CPT testing sessions. Celeration line slopes were compared between testing sessions using paired t-tests. No differences were identified for recovery slopes for HR (p = .295), diastolic BP (p = .300), and relative V̇O2 (p = .176) when comparing CPT-only and WAT+CPT testing sessions. Our results suggest that the CPT elicits a CV and metabolic response beyond that elicited solely by an acute bout of anaerobic exercise. As such, the CPT may be able to serve as a surrogate test for anaerobic exercise for individuals where high-intensity exercise may be contraindicated. Future research is warranted however, as the specific physiological mechanisms governing the observed responses have yet to be elucidated.

Evaluation of Early Submaximal Exercise Tolerance in Adolescents with Symptomatic Sport-related Concussion.

PURPOSE: This study aimed to compare cardiorespiratory response to a graded aerobic exercise challenge between adolescents with symptomatic sport-related concussion (SSRC) and healthy control subjects. METHODS: A quasiexperimental nonrandomized study at a multidisciplinary pediatric concussion program was conducted. Thirty-four adolescents with SSRC (19 males and 15 females) and 40 healthy control subjects (13 males and 27 females) completed the Buffalo Concussion Treadmill Testing (BCTT) until either symptom exacerbation or volitional fatigue. Main outcome measures included heart rate (HR), oxygen consumption (V˙O2), carbon dioxide production (V˙CO2), and minute ventilation (V˙E) at rest and at test termination, and change from rest in variables (ΔHR, ΔV˙O2, ΔV˙CO2, and ΔV˙E) during the first five stages of the BCTT. Main outcomes were analyzed using three-way mixed-model ANOVA, with group status (control vs SSRC) and sex (male vs female) as between-subject factors, and time (BCTT stage) as the within-subject factor. RESULTS: No group differences in resting HR, systolic and diastolic blood pressure, ΔV˙O2, V˙CO2, and V˙E were observed. During the first five stages of the BCTT, no group differences in ΔV˙O2, V˙CO2, and V˙E were observed; however, SSRC patients demonstrated higher RPE (P < 0.0005) compared with control subjects. No sex-based differences were observed among SSRC patients on measures collected at rest and during early stages of BCTT. CONCLUSIONS: Although SSRC patients exhibited higher RPE during a graded aerobic exercise challenge, no differences in cardiorespiratory response were observed compared with control subjects exercising at equivalent workloads. Further work is needed to elucidate the physiological mechanisms underlying exercise intolerance after SSRC.

Three-Year Longitudinal Fitness Tracking in Top-Level Competitive Youth Ice Hockey Players.

Cordingley, DM, Sirant, L, MacDonald, PB, and Leiter, JR. Three-year longitudinal fitness tracking in top-level competitive youth ice hockey players. J Strength Cond Res 33(11): 2909-2912, 2019-The purpose of this retrospective review was to report the physical and physiological development of top-level competitive male youth hockey players for 3 consecutive years (13, 14, and 15 years of age). Before each hockey season, the athletes (n = 103) underwent a fitness testing combine to assess aerobic, anaerobic, and musculoskeletal fitness. The tests performed included the height, body mass, body fat percentage determined by skinfolds, push-ups, chin-ups, plank, broad jump, grip strength 20-m shuttle run, Wingate bike test, and 5-10-5 shuttle test. Height and body mass increased with each consecutive year (p < 0.05) with no change in body fat percentage. Chin-ups, broad jump, and grip strength all improved with age (p < 0.001). However, push-ups only improved from 13 to 14 years of age (p < 0.001), whereas maximal plank duration decreased from 14 to 15 years of age (p < 0.05). The total distance covered during the 20-m shuttle run decreased from 14 to 15 years of age (p < 0.05). Absolute peak and average power increased with each age increase (p < 0.001), but relative peak and average power only increased from 13 to 14 years of age (p < 0.05). There was no change in the fatigue index with age. The 5-10-5 shuttle test improved with each age increase (p < 0.05). Over a 3-year period (13-15 years of age), there are many physical and physiological changes that occur in top-level competitive male hockey players. Having a better understanding of how these athletes develop could aid in the implementation of specific on- and off-ice training programs.

Early Subthreshold Aerobic Exercise for Sport-Related Concussion: A Randomized Clinical Trial.

Importance: Sport-related concussion (SRC) is a significant public health problem without an effective treatment. Objective: To assess the effectiveness of subsymptom threshold aerobic exercise vs a placebo-like stretching program prescribed to adolescents in the acute phase of recovery from SRC. Design, Setting, and Participants: This multicenter prospective randomized clinical trial was conducted at university concussion centers. Male and female adolescent athletes (age 13-18 years) presenting within 10 days of SRC were randomly assigned to aerobic exercise or a placebo-like stretching regimen. Interventions: After systematic determination of treadmill exercise tolerance on the first visit, participants were randomly assigned to a progressive subsymptom threshold aerobic exercise or a progressive placebo-like stretching program (that would not substantially elevate heart rate). Both forms of exercise were performed approximately 20 minutes per day, and participants reported daily symptoms and compliance with exercise prescription via a website. Main Outcomes and Measures: Days from injury to recovery; recovery was defined as being asymptomatic, having recovery confirmed through an assessment by a physician blinded to treatment group, and returning to normal exercise tolerance on treadmill testing. Participants were also classified as having normal (<30 days) or delayed (≥30 days) recovery. Results: A total of 103 participants were included (aerobic exercise: n = 52; 24 female [46%]; stretching, n = 51; 24 female [47%]). Participants in the aerobic exercise group were seen a mean (SD) of 4.9 (2.2) days after the SRC, and those in the stretching group were seen a mean (SD) of 4.8 (2.4) days after the SRC. There were no differences in age, sex, previous concussions, time from injury, initial symptom severity score, or initial exercise treadmill test and physical examination results. Aerobic exercise participants recovered in a median of 13 (interquartile range [IQR], 10-18.5) days, whereas stretching participants recovered in 17 (IQR, 13-23) days (P = .009 by Mann-Whitney test). There was a nonsignificant lower incidence of delayed recovery in the aerobic exercise group (2 participants [4%] in the aerobic group vs 7 [14%] in the placebo group; P = .08). Conclusions and Relevance: This is, to our knowledge, the first RCT to show that individualized subsymptom threshold aerobic exercise treatment prescribed to adolescents with concussion symptoms during the first week after SRC speeds recovery and may reduce the incidence of delayed recovery. Trial Registration: ClinicalTrials.gov identifier: NCT02710123.

Physical fitness of medical residents: Is the health of surgical residents at risk?

Background: Postgraduate medical residency programs are laborious and timeintensive, and can be physically, intellectually and emotionally demanding. These working conditions may lead to the neglect of personal health and well-being. The objective of this study was to compare the anthropometric and fitness characteristics of surgical and nonsurgical medical residents. We hypothesized that there is a difference in physical health between these 2 groups. Methods: Medical residents completed a demographic information questionnaire and were assessed by trained staff for height, weight, body fat percentage, muscular strength and endurance, and peak oxygen consumption (V̇ᴏ2peak). The average number of working hours per week was also documented. Results: Forty-five residents (21 surgical and 24 nonsurgical; 31 men and 14 women) participated in the study. Surgical residents worked more hours per week on average than nonsurgical residents (p = 0.02) and had a higher body mass index (BMI) (p = 0.04) and lower V̇ᴏ2peak (p = 0.01). Conclusion: Surgical residents worked more hours than nonsurgical residents, which may have contributed to their higher BMI and lower aerobic fitness levels. Despite a heavy workload, it is important for all medical residents to find strategies to promote a healthy lifestyle for both themselves and their patients to ensure long-term well-being.

Contexte: En médecine, les programmes de résidence postdoctoraux sont fastidieux et chronovores; et ils peuvent être exigeants physiquement, intellectuellement et émotivement. De telles conditions de travail forcent parfois les résidents à négliger leur santé et leur bien-être personnels. L'objectif de cette étude était de comparer les caractéristiques anthropométriques et la forme physique des résidents de chirurgie et d'autres spécialités médicales. Selon notre hypothèse, ces 2 groupes ne présentent pas le même état de santé physique. Méthodes: Les résidents ont répondu à un questionnaire démographique et des assistants dument formés ont mesuré leur taille, leur poids, leur pourcentage de graisse corporelle, leur force musculaire, leur endurance et leur consommation d'oxygène maximale (V̇ᴏ2max). Le nombre d'heures de travail hebdomadaires a aussi été pris en compte. Résultats: Quarante-cinq résidents (21 de chirurgie et 24 d'autres spécialités; 31 hommes et 14 femmes) ont participé à l'étude. Les résidents en chirurgie travaillaient en moyenne plus d'heures par semaine que les autres résidents (p = 0,02) et présentaient un indice de masse corporelle (IMC) plus élevé (p = 0,04) et une V̇ᴏ2max plus basse (p = 0,01). Conclusion: résidents en chirurgie travaillaient plus d'heures que les autres résidents, ce qui peut avoir contribué à leur IMC plus élevé et à leur moins bonne capacité aérobique. Malgré la lourdeur de leur fardeau de travail, il est important que tous les résidents en médecine trouvent des stratégies pour adopter de saines habitudes de vie pour eux-mêmes et leurs patients, et assurer leur mieux-être à long terme.

Evaluation of a Medically Supervised Concussion Protocol for Youth Hockey in Canada.

OBJECTIVES: The objective of this study was to evaluate the feasibility and implementation of a standardized medically supervised concussion protocol established between a city-wide AAA hockey league and a multi-disciplinary concussion program. METHODS: We conducted a retrospective review of injury surveillance, clinical and healthcare utilization data from all athletes evaluated and managed through the Winnipeg AAA Hockey concussion protocol during the 2016-2017 season. We also conducted post-season email surveys of head coaches and parents responsible for athletes who competed in the same season. RESULTS: During the 2016-2017 season, 28 athletes were evaluated through the medically supervised concussion protocol, with two athletes undergoing evaluation for repeat injuries (a total of 30 suspected injuries and consultations). In all, 96.7% of the athletes managed through the concussion protocol were captured by the league-designated Concussion Protocol Coordinator and 100% of eligible athletes underwent complete medical follow-up and clearance to return to full hockey activities. Although 90% of responding head coaches and 91% of parents were aware of the concussion protocol, survey results suggest that some athletes who sustained suspected concussions were not managed through the protocol. Head coaches and parents also indicated that athlete education and communication between medical and sport stakeholders were other elements of the concussion protocol that could be improved. CONCLUSION: Successful implementation of a medically supervised concussion protocol for youth hockey requires clear communication between sport stakeholders and timely access to multi-disciplinary experts in traumatic brain and spine injuries. Standardized concussion protocols for youth sports may benefit from periodic evaluations by sport stakeholders and incorporation of national guideline best practices and resources.

A Physiological Approach to Assessment and Rehabilitation of Acute Concussion in Collegiate and Professional Athletes.

Sport-related concussion is an important condition that can affect collegiate and professional athletes. Expert consensus guidelines currently suggest that all athletes who sustain acute concussion be managed with a conservative approach consisting of relative rest and gradual resumption of school and sport activities with active intervention reserved for those with persistent post-concussion symptoms lasting >10-14 days for adults. Unfortunately, these recommendations place little emphasis on the rapid physical deconditioning that occurs in athletes within days of exercise cessation or the pathophysiological processes responsible for acute concussion symptoms that can be successfully targeted by evidence-based rehabilitation strategies. Based on our evolving approach to patients with persistent post-concussion symptoms, we now present an updated physiological approach to the initial medical assessment, rehabilitation, and multi-disciplinary management of collegiate and professional athletes with acute concussion. Utilizing the results of a careful clinical history, comprehensive physical examination and graded aerobic exercise testing, we outline how team physicians, and athletic training staff can partner with multi-disciplinary experts in traumatic brain injury to develop individually tailored rehabilitation programs that target the main physiological causes of acute concussion symptoms (autonomic nervous system dysfunction/exercise intolerance, vestibulo-ocular dysfunction, and cervical spine dysfunction) while maintaining the athlete's physical fitness during the recovery period. Considerations for multi-disciplinary medical clearance of collegiate and professional athletes as well as the application of this approach to non-elite athletes are also discussed.

Development of Anaerobic Fitness in Top-Level Competitive Youth Ice Hockey Players.

Leiter, JR, Cordingley, DM, and MacDonald, PB. Development of anaerobic fitness in top-level competitive youth ice hockey players. J Strength Cond Res 32(9): 2612-2615, 2018-Ice hockey is a physiologically complex sport involving both the anaerobic and aerobic energy systems. The purpose of this study was to evaluate the anaerobic power output (PO) of top-level competitive youth hockey players. It was hypothesized that with each successive increase in age, there would be an associated change in anaerobic PO. Two hundred and fifty-one male hockey players between the ages of 13-17 years participated in this study. All athletes completed a 30-second Wingate test as part of a preseason physiological and fitness combine. A 1-way analysis of variance was performed to compare peak PO (POpeak), average PO (POavg), and fatigue index between all age groups. A Tukey's post hoc test was used to determine changes in immediately successive age groups for all variables. Age categories were grouped as 13 years old (yrs) (n = 72), 14 yrs (n = 68), 15 yrs (57) and 16 yrs (n = 54, including 11 athletes 17 yrs). Absolute POpeak significantly increased with all age increases. Relative POpeak, absolute POavg, and relative POavg increased between the ages of 13 and 14 years, and 14 and 15 years, but not between the ages 15 and 16 years. There were no changes in fatigue index between any successive age groups. Anaerobic PO increases with an increase in age with no associated change in fatigue index. Athletes, coaches, and parents can use this normative data to help prepare the player for upcoming seasons in which there may be an increase in level or age class.