• Can Attention Focus Instructions Reduce the Effects of Fatigue on Balance Control?

      Huff, Richard; Applied Health Sciences Program (Brock University, 2014-09-10)
      Localized muscular fatigue has been identified to have detrimental effects on balance control, an important skill for everyday life. Manipulation of attention focus instructions has been shown to benefit performance of various motor skills including balance and has been found to facilitate endurance during fatiguing tasks. The purpose of this thesis was to determine if the use of attention focus instructions could attenuate the effects of muscular fatigue on balance control. Twenty-four participants performed a balance task (two-legged stance on an unstable platform) before and after a fatigue protocol. Trunk sway, platform excursions, and lower limb muscle activity was measured. Results suggest that use of either internal or external attention focus instructions can reduce the immediate effects of muscular fatigue of the lower limb on balance control as shown through reduced trunk sway and platform excursions. These results have relevance for individuals performing balance tasks in a fatigued state.
    • Capacity and transformational development within the 2005 Canada Summer Games host society

      Marunchak, Katrusia.; Applied Health Sciences Program (Brock University, 2006-05-19)
      Although capacity has been used in recent federal government accords and policies related to the voluntary and amateur sport sectors, there is little consensus over the meaning of the term. Consequently, the purpose of this qualitative case study was to explore the concept of organizational capacity within a temporary voluntary sport organization. Specifically, the nature of organizational capacity was examined within the case of the Volunteers Division of the 2005 Canada Summer Games (CSG) Host Society. Data were collected from executive planning and middle management CSG volunteers through the use of a variety of methods: verbal journals, interviews, observations, documents and a focus group. Findings indicated several challenges associated with the volunteer management model utilized by the host society, varying levels of importance among six elements of capacity, and key aspects of the relationship between organizational capacity and transformational development. Implications focused upon the importance of highlighting individuals rather than the organizational as a whole in order to build capacity, and utilizing a brain or hybrid brain-machine organizational form to enhance capacity. Recommendations are provided for both the Canada Games Council and Canada Games host societies.
    • The capillary supply of human skeletal muscle in health and disease

      Kadyan, Mamta.; Applied Health Sciences Program (Brock University, 2006-06-04)
      BACKGROUND: Capillaries function to provide a surface area for nutrient and waste exchange with cells. The capillary supply of skeletal muscle is highly organized, and therefore, represents an excellent choice to study factors regulating diffusion. Muscle is comprised of three specific fibre types, each with specific contractile and metabolic characteristics, which influence the capillary supply of a given muscle; in addition, both environmental and genetic factors influence the capillary supply, including aging, physical training, and various disease processes. OBJECTIVE: The present study was undertaken to develop and assess the functionality of a data base, from which virtual experiments can be conducted on the capillary supply of human muscle, and the adaptations of the capillary bed in muscle to various perturbations. METHODS: To create the database, an extensive search of the literature was conducted using various search engines, and the three key words - "capillary, muscle, and human". This search yielded 169 papers from which the data for the 46 variables on the capillary supply and fibre characteristics of muscle were extracted for inclusion in the database. A series of statistical analyses (ANOVA) were done on the capillary database to examine differences in skeletal muscle capillarization and fibre characteristics between young and old individuals, between healthy and diseased individuals, and between untrained, endurance trained, endurance welltrained, and resistance trained individuals, using SAS. RESULTS: There was a significantly higher capillarization in the young compared to the old individuals, in the healthy compared to the diseased individuals, and in the endurance-trained and endurance well-trained compared to the untrained individuals. CONCLUSIONS: The results of this study support the conclusion that the capillary supply of skeletal muscle is closely regulated by factors aimed at optimizing oxygen and nutrient supply and/or waste removal in response to changes in muscle mass and/or metabolic activity.
    • Carbohydrate refeeding rapidly reverses the adaptive upregulation of human skeletal muscle pyruvate dehydrogenase kinase following a high fat diet

      Bigrigg, Jonathan Kent.; Applied Health Sciences Program (Brock University, 2004-07-14)
      The time course for the reversal of the adaptive increase in pyruvate dehydrogenase kinase (PDK) activity following a 6d high fat diet (HP: 4.2 ± 0.2 % carbohydrate; 75.6 ± 0.4 % fat; 19.5 ± 0.8 % protein) was investigated in human skeletal muscle (vastus lateralis). HF feeding increased PDK activity by 44% (from 0.081 ± 0.025 min"' to 0.247 ± 0.025 mm\p < 0.05). Following carbohydrate re-feeding, (88% carbohydrate; 5% fat; 7% protein), PDK activity had returned to baseline (0.111 ± 0.014 min"') within 3h of re-feeding. The active fraction of pyruvate dehydrognease (PDHa) was depressed following 6d of the HF diet (from 0.89 ± 0.21 mmol/min/kg WW to 0.32 ± 0.05 mmol/min/kg ww,p <0.05) and increased to pre-HF levels by 45 min of post re-feeding (0.74 ±0.19 mmol/min/kg ww) and remained elevated for 3h. Western blotting analysis of the PDK isoforms, PDK4 and PDK2, revealed a 31% increase in PDK4 protein content following the HF diet, with no change in PDK2 protein. This adaptive increase in PDK4 protein content was reversed with carbohydrate re-feeding. It was concluded that the adaptive up-regulation in PDK activity and PDK4 protein content was fiilly reversed by 3h following carbohydrate re-feeding.
    • Cardiac Rehabilitation Maintenance and Prevention Exercise Program: Effects on Depression and Body Image

      Madanat, Sara; Applied Health Sciences Program
      In Ontario, individuals who have experienced a cardiac event are prescribed to participate in cardiac rehabilitation. Most research examining the effectiveness of cardiac rehabilitation has focused on early phases (i.e., phase 1 and 2) and virtually none has looked at phase 3 maintenance programs, nor have they examined prevention-based programs. Therefore, this study looked at characteristics of those attending a cardiac rehabilitation maintenance and prevention exercise program, differences between those that finished 6-months of the program and those who did not, and the effects of the program on body image and depression. Eligible members (n = 111 males, n = 101 females, Mage = 63.3) of the Brock-Niagara Centre for Health and Well-Being completed anthropometric tests (height, body mass, heart rate, blood pressure) and self-reported measures of body satisfaction and depression at baseline and after 6 months of participating in the program. At baseline, individuals were identified as being at risk for clinical depression and were slightly dissatisfied with their body function and appearance. Three separate two-way ANCOVAS (for depression, satisfaction with function and satisfaction with appearance) showed that responders reported more favorable psychological profiles than non-responders at baseline, with significantly higher levels of satisfaction with body appearance [F (1, 204) = 5.95, p < .05] and function [F (1, 203) = 8.58, p < .05], albeit no differences in depression scores [F (1, 206) = .78, p > .05]. However, men did report lower satisfaction with their body function than women. A two-way mixed MANCOVA was conducted to examine changes in depression and body satisfaction across the 6-month program; there was no significant overall effect [F (1, 67) = 1.48, p > .05]. Our findings suggest that moderately active men and women may not differ on satisfaction with appearance. Given that those who completed 6-months of the program reported higher satisfaction with appearance and function than those who did not, it may be possible to identify those who are likely to drop out of a cardiac rehabilitation maintenance and prevention exercise program and develop programming to improve body image upon program entry to increase adherence.
    • Cardiovascular and Cognitive Adaptations Following Isometric Handgrip Exercise Training in Hypertensive Adults

      Dempster, Kylie Samantha; Applied Health Sciences Program
      Isometric handgrip (IHG) exercise training is an effective method of blood pressure (BP) reduction in clinical and non-clinical populations. The efficacy of IHG on cardiovagal baroreflex sensitivity (cvBRS) and systemic arterial stiffness (i.e. carotid-toe pulse wave velocity (ctPWV)) is less well understood, especially in hypertensive populations who demonstrate increased arterial stiffness and decreased BRS. Furthermore, hypertension is considered an accelerated model of cognitive decline, often attributed to the effects of increased BP and arterial stiffness. This study utilized IHG (n=8) and CON groups (n=4) to examine the effects of 8-weeks of IHG training or no IHG training on arterial stiffness, cvBRS, and cognitive function in hypertensive adults. Significant group differences in SBP and ctPWV change was observed (p<0.05) indicating that IHG training reduced SBP and systemic arterial stiffness compared to no IHG training. Moreover, although not significant (p>0.05), the IHG group demonstrated an ~53% increase in BRS. Lastly, a significant difference in Trail Making Test Part A (TMT-A) time (p<0.001) was observed in the IHG group, suggesting that IHG training improved motor, and visual control and speed. These findings suggest that IHG training can improve systemic arterial stiffness and possibly cvBRS in a hypertensive population, in addition to the new potential for improving specific aspects of cognitive function.
    • The cardiovascular hemodynamic responses to various levels of orthostatic stress in children

      Livingstone, Kristina.; Applied Health Sciences Program (Brock University, 2007-06-09)
      The ability of the cardiovascular system to quickly and efficiently adapt to an orthostatic stress is vital for the human body to function on earth. The way in which the various aspects of the cardiovascular system work together to counteract an orthostatic stress has been previously quantified in the adult population. However, there are still many unknowns surrounding the topic of how the cardiovascular system functions to cope with this same stress in children. The purpose of this study was to describe the cardiovascular hemodynamic adaptations to various levels of orthostatic stress induced using a lower body negative pressure (LBNP) chamber in pre-pubertal boys. A secondary purpose was to determine indices of baroreceptor sensitivity (BRS) at both rest and during low levels of LBNP in this same pediatric sample. Finally, this study aimed to compare the relative responses to LBNP between the children and adults. To complete the study 20 healthy pre-pubertal boys and adult males (9.3 ± 1.1 and 23 ± 1.8 years of age respectively) were recruited and randomly exposed to three levels of LBNP (15, 20 and 25 mmHg). At rest and during the application of the LBNP heart rate (HR), manual and bcat-by-beat systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP) were monitored continuously. Aortic diameter was measured at rest and peak aortic blood velocity (PV) was recorded continuously for at least I minute during each baseline and LBNP condition. From the raw data HR, stroke volume (SV), cardiac output (Q), total peripheral resistance (TPR), low frequency baroreceptor sensitivity (LF BRS), high frequency baroreceptor sensitivity (HF BRS) and LFIIIF ratio were calculated. At rest, llR wa'i higher and SBP, SV, Q and LF/HF ratio were lower in the children compared to the adult males (pgJ.05). In response to the increasing LEN!> IIR and TPR increased, and LF BRS. SV and Q decreased in the adult group (pSf).05). while the same levels of LBNP caused an increase in TPR and a decrease in SBP, SV and Q in the children (pSf).05). Although not significant, the LF/HF ratio in the adult group showed an increasing trend in response to increased negative pressure (p=O.088). As for resting BRS, there were no significant differences in LF or HF BRS between the children and the adults despite a tendency for both measures to be 18% lower in the children. Also the LF/HF ratio was almost significantly greater in the adults compared to the children (p=O.057). In addition, a comparison between the relative adult and child responses to LBNP yielded no significant group by level interactions. This result should be taken with caution though, as the low sample size and high measurement variability generated very low statistical power for this analysis. In conclusion, the results of this study suggest that the hemodynamic adaptations to an orthostatic stress were less pronounced in the prepubertal males, most likely due to an underdeveloped autonomic system. These results need to be strengthened by further research before any implications can be derived for health care purposes.
    • The case of Grindr and gay men’s embodiment and body image through new media

      Oshana, David; Applied Health Sciences Program
      Grindr is a geo-social based dating application (app) that allows men who have sex with men (MSM) to connect with each other based on sexual preferences and appearance. The popularization of Grindr over the last decade and its major influence on the MSM community has brought about new queries into its usage, body image, and masculine (dis)embodiment, particularly due to its userbase being heavily appearance-focused. MSM in general are an understudied demographic in the body image literature. MSM have reported greater negative body image than their heterosexual counterparts pertaining to masculine identity, physical appearance, and sexualized self-presentation. To investigate the relationship between Grindr, body image, and MSM’s (dis)embodiment, a qualitative case study design was utilized. Nine MSM who had used Grindr took part in a semi-structured interview. Two data-driven themes were identified from the reflexive thematic analysis process; ‘No fats, no femmes, no Asians’ which explored the issues of social performativity and body image experiences on Grindr; and ‘Grindr doesn’t allow for… people to really express themselves’ which explored the experiences of using cyberspace dating and its effects on body image and self-presentation. Participants unanimously identified that their experiences on Grindr were catalysts for maladaptive behaviors, including excessive exercise, self-objectification, and disembodiment pertaining to their genuine self-identity. Body image was described as both a relationship one has with their body and as the ascription of others’ opinions of one’s body. The disembodiment expressed was related to notions of performative masculinity to gain attention rather than being true to one’s self. Additionally, it was identified that for appearance-focused MSM, there remains issues of understanding what (positive) body image actually is. Participants described the complex relationships between sexual performativity, short-term satisfaction, and the necessity of others’ opinions for understanding their (positive) body image. Ultimately, Grindr was identified to be a negative cyberspace which facilitates curated ideal-self presentation that focuses on self-objectification for the pleasure of other MSM as a way of being perceived as desirable.
    • A Case Study to Explore Women's Body Image Experiences Practicing Hot Yoga

      Rose, Hannah; Applied Health Sciences Program
      Yoga is an embodying activity associated with positive body image; however, hot yoga may have differing impacts on body image and embodiment than traditional yoga, as several features of hot yoga differ from traditional yoga (e.g., heat, clothing worn, emphasis on fitness) and may influence women’s body image and practice of hot yoga. Using an exploratory case study approach, one hot yoga studio (Modo Yoga St. Catharines) was chosen for this study. The research questions pertaining to this case were: 1) In what ways is body image related to women’s practice of hot yoga? 2) What are women’s experiences practicing hot yoga at Modo Yoga studio St. Catharines? Ten women were recruited from the yoga studio and interviewed about their body image and experience practicing yoga at Modo Yoga. Four women, with differing experiences and body image, completed a follow-up interview to further clarify their experiences. Overall, it was found that women tended to emphasize the fitness aspects of hot yoga, which impacted their body image and undermined some benefits of yoga. However, there were also positive effects on body image and mental health as a result of the practice. Case-specific features, specifically related to the physical characteristics of the studio (e.g., large mirrors in the studio) and the social environment within the studio (i.e., instructor cues and other members) impacted women’s body image both positively and negatively. Further, some differences based on age and experience at the studio were also identified, with long-term members (6 months+) experiencing more psychological benefits (e.g., mindfulness, feeling less anxious, body acceptance, body responsiveness), with the physical challenges of hot yoga being an additional benefit. Overall, hot yoga had a complex impact on women’s body image and experience practicing hot yoga through a larger focus on the fitness elements of the practice.
    • Changes in Body Mass, Body Composition, Physical Activity and Nutrition from the First to the Fourth Academic Year in University Students

      Olansky, Shai; Applied Health Sciences Program
      Background: The transition to university life is a critical time of change, often accompanied by the adoption of negative lifestyle habits, including an unhealthy diet and a decrease in physical activity. Lifestyle changes during university may result in a positive energy balance and a decrease in diet quality, which can lead to weight gain, a percent body fat in the overweight/obesity range, and increased cardiometabolic disease risk over time. The purpose of the current study was to investigate changes in body mass and composition from 1st to 4th year among university students, and to assess whether changes in physical activity and dietary intake were related to observed changes in body mass and composition. Methods: Thirty-eight participants completed food frequency and activity questionnaires and had their body mass measured and body composition assessed using bioelectrical impedance analysis. These measurements were obtained at the beginning (fall) and end (spring) of 1st year and the end (spring) of 4th year. Results: During the 1st year, body mass and percent fat increased by 3.2 kg and 2.1%, respectively (P<0.01), while daily energy intake was maintained and daily energy expenditure decreased (-435.2 kcal/day, P<0.01). Between the end of the 1st year and the end of the 4th year, students continued to increase their body mass, but this increase was smaller (+2.2 kg, P=0.05) than the change occurring during the 1st year. Additionally, percent fat and energy intake did not change while energy expenditure increased from the end of 1st year to the end of 4th year (+208.6 kcal/day, P<0.01). Conclusions: Increases in percent body fat during university occurred only during the 1st year. However, students were not able to reverse these gains by the end of the 4th year.
    • Changes in mitochondrial PLIN3 and PLIN5 protein content in rat skeletal muscle following acute contraction and endurance training

      Ramos, Sofhia; Applied Health Sciences Program (Brock University, 2014-11-03)
      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.
    • Changes in Periodontal Status after Pandemic-Related Interruptions to Care in a Fragile Cohort

      Young, Hannah; Applied Health Sciences Program
      Sanative therapy (ST) can be a highly effective first-line therapy for periodontal disease. However, even after successful ST, patients require life-long periodontal maintenance therapy (PMT) to maintain their periodontal health. As a result of the COVID-19 global pandemic, stay-at-home orders and other public health measures resulted in many patients missing or delaying their regularly scheduled PMT appointments. The primary objective of this study was to determine, at 5 to 10 years post-ST, if patients who delayed their appointments as a result of COVID-19 experienced significant changes in periodontal probing depth (PPD), bleeding on probing (BOP), and plaque index (PI) compared to patients without appointment delays. Additionally, lifestyle factors such as dietary intake, physical activity, and oral hygiene behaviors were hypothesized to have been altered because of the COVID-19 pandemic, and interview questions were used to capture these changes. The study was completed at a private periodontal clinic. Patient medical and dental history data was collected retrospectively from patient charts. Due to challenges with recruitment, a subset of the required sample size was studied with findings providing pilot data for a larger future study. Study participants (n = 12) were asked to complete two different physical activity questionnaires, a 24-hour dietary recall, and a supplement and tea questionnaire online. Furthermore, a short virtual interview was used to ask participants how they felt COVID-19 impacted several lifestyle factors. At 5 to 10 years post-ST, a short delay in PMT appointments of 2 – 6 months did not significantly affect PPD, BOP and PI. Most participants reported changes to physical activity (80%) and diet (80%), but no changes to oral hygiene behaviors (90%). Overall, physical activity, diet, and body mass index data in the study sample closely aligned with findings from larger studies that have assessed these aspects in the Canadian population. This pilot study should be used to design future studies aimed at investigating the relationship between periodontal health and behavioral changes resulting from the COVID-19 pandemic.
    • Characterization of Neutral Sphingomyelinase Isoforms in Skeletal Muscle Mitochondria

      Silvera, Sebastian; Applied Health Sciences Program
      Skeletal muscle is composed of fiber types that differ in mitochondrial content, antioxidant capacity, and susceptibility to apoptosis. Ceramides have been linked to apoptosis by increasing mitochondrial permeability, a common hallmark of apoptotic signalling. The enzyme neutral sphingomyelinase (nSMase) generates ceramides by hydrolysing sphingomyelin. Despite the role of ceramides in mediating apoptosis, there is a gap in the literature regarding nSMase in skeletal muscle mitochondria. This study aimed to characterize activity and content of nSMase isoforms in isolated subsarcolemmal (SS) mitochondria from soleus, diaphragm, plantaris, and extensor digitorum longus (EDL). Total nSMase activity did not differ between isolated SS mitochondria. nSMase2 content was higher in SS mitochondria from EDL compared to soleus or diaphragm, and positively correlated to total nSMase activity in soleus. nSMase3 was undetectable in all samples, suggesting it is not associated with SS mitochondria, and likely does not contribute to total nSMase activity in SS mitochondria.
    • Characterizing RyR and SERCA function in the C57 and D2 mdx mouse models of Duchenne Muscular Dystrophy

      Cleverdon, Riley; Applied Health Sciences Program
      Duchenne Muscular Dystrophy (DMD) is a male-affected muscle wasting disease caused by the complete loss of the sarcolemmal protein dystrophin. No cure exists and patients typically succumb to cardiorespiratory issues in the third or fourth decade of life. Dystrophin loss also leads to dysfunction in other pathways; including impaired sarcoplasmic reticulum (SR) calcium (Ca2+) handling, further perpetuating the disease. This thesis examined potential differences in SR Ca2+ handling in two mouse models of DMD. The D2.B10-Dmdmdx/J (D2 mdx) mouse has emerged as a more pathologically representative model of DMD than the C57BL/10ScSn-Dmdmdx/J (C57 mdx) mouse model, showing greater muscle weakness, wasting and earlier disease onset. However, SR Ca2+ has not yet been characterized in the D2 mdx mouse. Thus, the aim of this study was to compare SR Ca2+ handling in the D2 mdx and C57 mdx mice. Using age-matched (9-10 week-old) mice, we found that D2 mdx mice had less mass, smaller gastrocnemius muscles, and were less ambulant. The D2 mdx mice had significantly higher energy expenditure and respiratory exchange ratio compared with the D2 WT mice. Two separate SR Ca2+ uptake assays revealed that D2 mdx mice have less Ca2+ uptake and leak, and higher starting myoplasmic Ca2+. SERCA activity (ATP hydrolysis) was lower in D2 mdx mice while higher in C57 mdx mice. These dramatic impairments in SR Ca2+ handling were not attributed to differences in SERCA isoform content or changes in its regulator, sarcolipin. However, under reducing conditions, protein nitration and nitrosylation content were significantly higher in D2 mdx gastrocnemius muscles. Further, pre-treatment with dithiothreiotol (DTT) did not improve SR Ca2+ handling in these muscles, suggestive of irreversible reactive oxygen/nitrogen post-translational modifications. Finally, calpain proteolytic activity was examined to determine the consequence of the impaired SR Ca2+ handling in the D2 mdx mouse. While D2 WT mice already had higher levels of calpain activity, the D2 mdx mouse had significantly higher calpain activity vs the C57 mdx mouse. Altogether, the results from this thesis suggest that impaired SR Ca2+ handling may be partially responsible for more severe pathology found in the D2 mdx mice.
    • Characterizing the role of tafazzin in allergically activated mast cells

      Maguire, Aindriu; Applied Health Sciences Program
      Introduction & Aim: Allergic inflammatory diseases are a constantly growing health concern in westernized societies. Mast cells, the driving force behind many allergic diseases, modulate various metabolic pathways to carry out their various functions following IgE-FceRI-mediated activation. Tafazzin is a cardiolipin transacylase that works to remodel cardiolipin into its mature form of tetralinoleoyl-cardiolipin. Mature cardiolipin is important for efficient energy production through oxidative phosphorylation. The aim of this project is to study the effects of a reduction in tafazzin protein content on IgE-mediated mast cell activation. Methods: Fetal liver-derived mast cells (FLMCs) were treated with 1 μg/mL doxycycline for 5 days to initiate the tafazzin knockdown. Western blotting was used to confirm a reduction in tafazzin protein content. Flow cytometry was used to ensure that the FLMCs expressed both c-kit and FceRI receptors, and that receptor expression was not impacted by the doxycycline treatment. Oxygen consumption rate was measured using a Clark-type electrode. b-hexosaminidase release assays were utilized to assess degranulation during the early phase of the allergic reaction. ELISA assays were used to examine secretion of de novo synthesized inflammatory mediators, while qPCR assays were used to examine gene transcription of these mediators. Results: The doxycycline inducible tafazzin knockdown resulted in a 99.5% reduction in tafazzin protein content. This reduction was accompanied by a 25% reduction in oxygen consumption and a 31.4% reduction in degranulation. Secretion of CCL1, CCL2, and TNF was significantly reduced, CCL9 secretion levels showed a decrease that approached significance. Secretion of CCL3 and IL-6 was not impacted. Gene expression was not impacted for any of the inflammatory mediators measured. Conclusion & Significance: These results suggest that tafazzin may play a role in mast cell oxidative phosphorylation. Functionally, the results suggest that tafazzin plays a role in degranulation and mediator secretion. However, since gene expression was not impacted it is thought that the tafazzin reduction causes these decreases due to an impairment of the exocytosis mechanism. This work adds to the growing field of immunometabolism and improves our understanding of how mast cells modulate metabolic pathways during an allergic inflammatory event.
    • Chronic versus acute ingestion of sodium citrate: a randomized placebo controlled cross-over trial for swimming 200 metres in well-trained swimmers age 13-17

      Russell, Colin; Applied Health Sciences Program (Brock University, 2013-07-19)
      A double-blinded, placebo controlled, cross-over design was used to investigate sodium citrate dihydrate (Na-CIT) supplementation improve 200m swimming performance. Ten well-trained, male swimmers (14.9 ± 0.4y; 63.5 ± 4kg) performed four 200m time trials: acute (ACU) supplementation (0.5g/kg), acute placebo (PLC-A), chronic (CHR) (0.1g/kg for 3 days and 0.3g/kg on the 4th day pre-trial), and chronic placebo (PLC-C). Na-CIT was administered 120min pre-trial in solution with 500mL of flavored water; placebo was flavored water. Blood lactate, base excess (BE), bicarbonate, pH, and PCO2 were analyzed at basal, 100min post-ingestion, and 3min post-trial via finger prick. Time, lactate, and rate of perceived exertion were not different between trials. BE and bicarbonate were significantly higher for the ACU and CHR trials compared to placebo. “Responders” improved by 1.03% (P=0.043) and attained significantly higher post-trial lactate concentrations in the ACU versus PLC-A trials and compared to non-responders in the ACU and CHR trials.
    • Clinical Depression, Antidepressant Use, and Metabolic Syndrome-related Comorbidities among Canadian Older Adults: A Cross-sectional Analysis of Baseline Data from the Canadian Longitudinal Study of Aging

      Son, Surim; Applied Health Sciences Program
      Background: Clinical depression is associated with a number of biological alterations and behaviours that can increase the risk of metabolic syndrome (MetS). Antidepressant medications (AD) are frequently used to treat depressed patients, but it often has side effects such as metabolic abnormalities. MetS is a well-known risk factor for multiple chronic diseases including cancer, and cardiovascular disease (CVD). However, it is unclear how clinical depression, AD use, and MetS are associated with cancer and CVD. Objective: To explore the relationship between clinical depression, AD use, and MetS-related chronic disorders, with a specific focus on cancer and CVD, and to assess how associations differ by MetS status, among Canadian older adults. Methods: The baseline data of the Canadian Longitudinal Study on Aging Comprehensive Cohort of 29,366 men and women aged 45 years and older was used in the analysis. Clinical depression was defined by self-reported clinical diagnosis of depression. Current depression treatment type was categorized into three groups: AD use only, other types of depression therapy, and no current depression therapy. MetS was defined by the harmonized criteria developed by the International Diabetes Federation, and American Health Association/National Heart, Lung, and Blood Institute. Logistic regression was used to estimate the associations of cancer or CVD on the basis of distribution of depression, current treatment types, and MetS. Results: The overall prevalence of clinical depression was 17.3%, and AD use was 8.1%. Compared to non-depressed individuals, depressed individuals taking AD had higher odds of colorectal cancer, and lung cancer. Depressed individuals using AD had higher odds of CVD, except peripheral vascular disease. Regardless of depression status, MetS showed no association with cancers. Among non-depressed individuals, MetS was associated with CVD compared to those without MetS. Within depressed individuals using AD, MetS did not appear to be associated with CVD. Conclusion: Clinical depression and AD use are associated with colorectal cancer, but the association may be independent of MetS. The positive associations between clinical depression, AD, and lung cancer or CVD were mitigated by comorbidity. MetS did not appear to play a role in the association between clinical depression, AD, and MetS-related chronic diseases.
    • The coach-athlete relationship in university female team sports : perceptions of moral agency and ethical considerations

      Lagzdins, Milaina.; Applied Health Sciences Program (Brock University, 2007-05-21)
    • Coaches' use of and impressions of computer-mediated communication (CMC) media /

      Lawrie, Kevin.; Applied Health Sciences Program (Brock University, 2009-06-15)
      The study examined coaches' usage of text-based computer-mediated communication (CMC) media (e.g., text-messaging, email) in the coach-player relationship. Data were collected by surveying Ontario-based male baseball coaches (n = 86) who coached players between 15 and 18 years old. Predictions were made regarding how demographic factors such as age and coaching experience affected coaches' CMC use and opinions. Results indicated that over 76% of respondents never used any CMC media other than email and team websites in their interactions with players. Results also revealed that coaches' usage rates contrasted with their opinion of the usefulness of the media, and their perception of players' use of the media. Coaches characterized most CMC media as limited, unnecessary, and sometimes inappropriate. Additional research should explore players' CMC usage rates and possible guidelines for use of the new media in authority relationships. Academia needs to keep pace with the developments in this area.
    • Comparing motives, goals and weight training behaviours of competitive and recreational weight trainers: An application of organismic integration theory and goal contents theory

      Burns, Matthew; Applied Health Sciences Program (Brock University, 2013-08-23)
      The study purpose was to examine differences between competitive and recreational weight trainers on indices of motivation, goals and behaviour. Data was collected from a purposive sample of competitive (n = 177; Mage = 30.86; SDage = 11.35) and recreational (n = 196; Mage = 21.97; SDage = 6.05) weight trainers using a cross-sectional, non-experimental design. Participants completed the Behavioural Regulation in Exercise Questionnaire-2R, Exercise Motivations Inventory-2, assessment of weight training behaviour and demographic questions. Multivariate analyses of variance indicated higher endorsement of autonomous motives and mostly intrinsically-oriented goals, while independent samples t-tests indicated higher frequency of weight training behaviour among the competitive weight trainers. Group differences were independent of demographic factors. Findings suggest that autonomous motives and intrinsic goals may not be undermined by competition among competitive weight trainers. This study also provides support for the utility of organismic integration theory and goal contents theory in examining strength-based exercise.