View overlooking the Hutton Sports Complex at Chapman College, Orange, California

View from Hashinger Hall overlooking the Hutton Sports Complex at Chapman College, Orange, California, 1979. Rooftops of residences and trees in the foreground; the stadium and athletics field in the background.

A Basis for Understanding Volunteer Coach Retention in Youth Sports

Youth sport organizations depend on volunteers to coach the teams in the organization. The purpose of this quantitative study was to develop a further understanding of volunteer coach retention in youth sport. The data was collected through a quantitative questionnaire which used close-ended and Likert-scale questions. The questionnaire collected data on the modified Model of Volunteer Retention in Youth Sports, reasons to withdraw from coaching and human resource management. There were 126 surveys collected from members of the three largest youth sport associations in the town of Aylmer, Ontario. The study found that Person-Task fit was the best predictor of volunteer coach retention as it significantly correlated to one’s intention to continue coaching (p< 0.01). Furthermore, additional reasons were found to explain withdrawal from coaching - if one’s child stops playing the sport or if coaching is too time consuming. The retention of volunteer coaches in youth sport organizations requires a multi-dimensional approach in understanding how to best retain volunteer coaches.

Peer Motivational Climate and its Relationship with Positive and Negative Affect in Intramural Sports

The study of peers as an influence on sport participation has received minimal exploration. The purpose of this cross-sectional study was to determine how peer created motivational climates (task-involved and ego-involved) impact positive and negative affective states of intramural sport participants post-participation. Three hundred and fifteen intramural sport participants (N=315) at a Canadian university completed a questionnaire after participating in their intramural sport. Hierarchical regression analyses and MANCOVAs were used to examine the effects of peer motivational climates on positive and negative affect. Results revealed that task-involved peer climates are more conducive of positive affective states post-participation whereas ego-involved climates result in lesser positive affective states and more negative affective states. Teams that promote improvement and effort instead of intra-team competition and conflict will have more positive recreational sport experiences. Future research should explore other psychological outcomes that can result from peer created motivational climates in recreational sport team settings.

Effect of increased milk intake combined with endurance exercise training on body composition, blood-lipids and inflammatory markers in overweight young males

Consuming low-fat milk (LFM) after resistance training leads to improvements in body composition. Habitual aerobic exercise and dairy intake are relatively easy lifestyle modifications that could benefit a population at risk for becoming obese. Thus, the purpose of this study was to investigate combining increased LFM intake with endurance exercise on body composition, blood-lipid profile and metabolic markers. 40 young males were randomized into four groups: one ingesting 750mL LFM immediately post-exercise, the other 6hrs post-exercise; and two isocaloric carbohydrate groups ingesting at the two different times. Participants completed a 12 week endurance-training program (cycling 1 hour/day at ~60%VO2peak, 5 days/week). 23 participants completed the study. Increases in lean mass (p < 0.05), and decreases in anti-inflammatory marker adiponectin (p < 0.05) were seen in all groups. No other significant changes were observed. Future analyses should focus on longer duration exercise and include a larger sample.

Influence of timing of milk consumption coupled with endurance training on body composition and endurance training adaptations in humans.

Consumption of low-fat milk (LFM) after resistance training has been shown to have positive influences on body composition and training adaptations; however, little research has examined the effects of LFM consumption following endurance training. The purpose of the study was to look at the effects of combining additional servings of LFM following endurance exercise on body composition, bone health, and training adaptations. 40 healthy males were recruited. Individuals were randomized into 4 groups – DEI (750mL LFM immediately post exercise), DEA (750mL LFM 4 hrs prior to or 6 hrs post exercise), CEI (750mL carbohydrate beverage immediately post-exercise), and CEA (750mL carbohydrate beverage immediately post-exercise). Participants took part in a 12-week endurance training intervention (1 h/day, 3 d/wk, ~60% max HR). 22 participants completed the study. Analysis showed significant increases in lean mass, spinal bone mineral content, relative VO2peak, and a decrease in Trap 5β across all groups (p < 0.05).

Changes in mitochondrial PLIN3 and PLIN5 protein content in rat skeletal muscle following acute contraction and endurance training

Surrounding lipid droplets in skeletal muscle are the perilipin (PLIN2-5) family of proteins, regulating lipid droplet metabolism. During exercise lipid droplets provide fatty acids to the mitochondria for oxidation while increasing their proximity to each other. Whether PLIN3 and PLIN5 associate with mitochondria following contraction has not been examined. To determine whether contraction altered mitochondrial PLIN3 and PLIN5 content, sedentary and endurance trained rats underwent acute contraction. The main outcomes are; 1) mitochondrial PLIN3 content is unaltered while mitochondrial PLIN5 content is increased following an acute contraction 2) mitochondrial PLIN3 content is higher in endurance trained rats when compared to sedentary and mitochondrial PLIN5 content is similar in both conditions 3) only PLIN5 mitochondrial content is increased similarly in both groups following acute contraction. This work highlights the dynamics of these two PLIN proteins, which may have roles not only on the lipid droplet but also on the mitochondria.

Skeletal muscle protein content of lipolytic inhibitor G(0)/G(1) switch gene-2 protein: the effect of endurance training

The first and rate-limiting step of lipolysis is the removal of the first fatty acid from a triglyceride molecule; it is catalyzed by adipose triglyceride lipase (ATGL). ATGL is co-activated by comparative gene identification-58 (CGI-58) and inhibited by the G(0)/G(1) switch gene-2 protein (G0S2). G0S2 has also recently been identified as a positive regulator of oxidative phosphorylation within the mitochondria. Previous research has demonstrated in cell culture, a dose dependent mechanism for inhibition by G0S2 on ATGL. However our data is not consistent with this hypothesis. There was no change in G0S2 protein content during an acute lipolytic inducing set of contractions in both whole muscle, and isolated mitochondria yet both ATGL and G0S2 increase following endurance training, in spite of the fact that there should be increased reliance on intramuscular lipolysis. Therefore, inhibition of ATGL by G0S2 appears to be regulated through more complicated intracellular or post-translation regulation.

Do Neuro-Muscular Adaptations Occur in Endurance-Trained Boys and Men?

Most research on the effects of endurance training has focused on endurance training's health-related benefits and metabolic effects in both children and adults. The purpose of this study was to examine the neuromuscular effects of endurance training and to investigate whether they differ in children (9.0-12.9 years) and adults (18.4-35.6 years). Maximal isometric torque, rate of torque development (RTD), rate of muscle activation (Q30), electromechanical delay (EMD), and time to peak torque and peak RTD were determined by isokinetic dynamometry and surface electromyography (EMG) in elbow and knee flexion and extension. The subjects were 12 endurance-trained and 16 untrained boys, and 15 endurance-trained and 20 untrained men. The adults displayed consistently higher peak torque, RTD, and Q30, in both absolute and normalized values, whereas the boys had longer EMD (64.7+/-17.1 vs. 56.6+/-15.4 ms) and time to peak RTD (98.5+/-32.1 vs. 80.4+/-15.0 ms for boys and men, respectively). Q30, normalized for peak EMG amplitude, was the only observed training effect (1.95+/-1.16 vs. 1.10+/-0.67 ms for trained and untrained men, respectively). This effect could not be shown in the boys. The findings show normalized muscle strength and rate of activation to be lower in children compared with adults, regardless of training status. Because the observed higher Q30 values were not matched by corresponding higher performance measures in the trained men, the functional and discriminatory significance of Q30 remains unclear. Endurance training does not appear to affect muscle strength or rate of force development in either men or boys.

The Beneficial Effects of Motivational Self-Talk on Endurance Performance and Cognitive Function in the Heat

The role of psychological strategies on endurance performance and cognitive function in the heat is unclear. This thesis tested the effects of a two-week motivational self-talk (MST) intervention - specific to heat stress - on endurance capacity and cognitive function in the heat (35°C 50% RH). The study utilized a pre-test / post-test design testing endurance capacity using a time to exhaustion test (TTE) after exercise-induced hyperthermia. Cognitive function (e.g executive function) was tested at baseline in thermoneutral (22°C 30% RH), before (R1) and after the TTE (R2). MST led to a significant improvement (~30%) in TTE and significantly faster completion time with fewer errors made on executive function tasks at baseline and R2, but not in R1, while there were no differences in the control group. Overall, these results indicate that using a top-down regulation strategy consisting of self-contextualized MST can improve physical and cognitive performance in the heat.

Long-term effects of sports concussion

Questions : Cette thèse visait à répondre à deux questions fondamentales : 1) Est-ce que les athlètes qui présentent un historique de commotions cérébrales du sport en conservent des effets délétères à long terme? ; et 2) Est-ce que les effets néfastes des commotions cérébrales récurrentes sur le fonctionnement tant cognitif que moteur sont cumulatifs? Devis expérimental : À l’aide d’un plan d’investigation double-cohorte réalisé avec un groupe d’athlètes évoluant au niveau universitaire et un autre formé d’anciens athlètes universitaires testés plus de trois décennies plus tard, les quatre études qui composent cette thèse ont employé des méthodes raffinées d’investigation des fonctions cognitives et motrices pour en déceler des atteintes persistantes. Méthodologie : Les potentiels évoqués cognitifs ainsi que les tests neuropsychologiques ont permis de sonder le fonctionnement cognitif de ces athlètes alors que la stimulation magnétique transcrânienne, une plateforme de force permettant de mesurer la stabilité posturale ainsi qu’un système d’enregistrement tridimensionnel des mouvements rapides alternatifs ont servi à l’évaluation de l’intégrité du système moteur. Résultats : Cette thèse a permis de déceler des altérations persistentes et cumulatives des fonctions cognitives et motrices. De plus, ces subtiles atteintes observées chez les jeunes athlètes, affectant essentiellement des marqueurs neurophysiologiques sous-cliniques du fonctionnement cognitif et moteur, s’étaient accentuées chez les anciens athlètes universitaires qui montraient un déclin quantifiable tant des fonctions cognitives que motrices. Discussion : Ces résultats suggèrent d’une part que les commotions cérébrales du sport entraînent des altérations cognitives et motrices chroniques qui s’accentuent en fonction du nombre de commotions cérébrales subies. D’autre part, les effets délétères des commotions cérébrales du sport sur le fonctionnement cognitif et moteur combinés à ceux associés au processus de vieillissement entraînent un déclin cognitif et moteur quantifiable en comparaison aux anciens athlètes n’ayant jamais subi de commotions cérébrales.

"They always remain girls" : la re/production des rapports de genre dans les sports féminins au Québec, 1919-1961

Cette thèse lève en partie le voile sur l’histoire des sports féminins au Québec de 1919 à 1961, soit de l’âge d’or des sports féminins au Canada jusqu’à l’adoption de la Loi sur la condition physique et le sport amateur par le gouvernement fédéral. Elle montre comment les rapports de genre ont été re/produits dans les sports féminins en étudiant les discours et les pratiques, tout en portant une attention particulière à l’influence qu’exercent l’appartenance de classe, l’ethnicité et la religion sur les sports féminins. L’analyse se penche d’abord sur les discours des médecins, des professeurs d’éducation physique et des clercs de l’Église catholique pour étudier les prescriptions qu’ils ont formulées à l’égard de la participation sportive des femmes. Les idées de deux Montréalaises, Myrtle Cook et Cécile Grenier, sont ensuite examinées pour montrer comment elles contestent les discours dominants. Enfin, les pratiques sportives des femmes dans deux centres sportifs montréalais, soit la Palestre nationale et le Young Women’s Christian Association, ont été étudiées de manière détaillée afin de mettre en lumière les différences, mais aussi certaines similitudes, entre l’organisation des sports féminins dans les communautés francophones et anglophones de la ville. Cette thèse met en évidence les tensions qui découlent des rapports de genre, de classe, d’ethnicité et de l’appartenance religieuse, et qui sont présentes à la fois dans les discours et les pratiques. Comme ailleurs en Amérique du Nord et même ailleurs en Occident, les discours dominants au Québec ne sont pas univoques, alors que des vues divergentes les contestent et que les pratiques sont plurielles. Tout en s’inscrivant dans le mouvement plus large d’accès des femmes aux sports en Occident, les discours et les pratiques observables à Montréal s’en distinguent, notamment par la forte influence de l’Église catholique et par les tensions ethniques. Le Québec est donc un cas d’espèce tout indiqué pour mettre en lumière la complexité de la re/production des rapports de genre à travers l’analyse des sports féminins, l’étude de ce champ constituant en même temps une avenue de recherche fort stimulante pour mieux saisir l’entrée de la province dans la modernité.

Évaluation de la spécificité de différents exercices d'endurance des muscles spinaux

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Effets d'un entraînement combiné en force et en endurance sur la performance en course à pied

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Étude longitudinale des caractéristiques individuelles associées à la pratique de sports extrêmes et rôle modérateur de facteurs socio-familiaux

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

L’évolution de la course à pied en endurance et ses impacts sur le corps humain

Travail d'intégration réalisé dans le cadre du cours PHT-6113.