22 June 2009
The four studies of this thesis provide an overview of the epidemiology of physical activity in Canada. In the first study two methods of coding activities used in estimating leisure-time physical activity energy expenditure (LTPAEE), from a questionnaire including 21 specific activities, and up to three “other” activities were compared. The authors assessed whether the assignment of activity intensity for “other” activities has an effect on LTPAEE and the classification of respondents as physically active versus inactive. The results indicate that the population classification of activity level is not affected by the intensity code; however, individual level LTPAEE is under-estimated from light and vigorous activities and over-estimated from moderate activities using the current method. In study two the proportion of Canadians meeting Canada’s physical activity guidelines for moderate and vigorous activities was estimated. The prevalence of adults reporting no activity has not changed since 1994/95 and the prevalence of meeting the guidelines has increased by about 11%. Men, younger adults, those with higher income and lower body mass index (BMI) meet the guidelines more often than their peers. The epidemiology of walking among Canadians between 1994 and 2007 was assessed in the third study. Walking was the most popular activity, regardless of age, sex, BMI or income group; however, only 30% of walkers walked regularly. Women, older adults, those with lower BMI and lower household income walk regularly more often than their counterparts. Women, older adults and lower income Canadians tended to derive 100% of their total LTPAEE from walking. An evaluation of whether meeting the guidelines for physical activity was associated with lower odds of chronic conditions and reporting fair/poor health was undertaken in study four. After adjustment for covariates, the odds of type 2 diabetes, obesity and reporting fair/poor health were significantly higher among those not meeting the guidelines for both sexes and for high blood pressure among women. Together these findings provide an understanding of the limitations of estimating LTPAEE, provide estimates of the proportion of Canadians meeting the guidelines for physical activity and provide insight into the relationship between meeting the guidelines and chronic conditions. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2009-06-18 16:18:44.998
Reliability of an On-line System to Assess Physical Activity Behaviors in an Active Group of Kinesiology Undergraduate StudentsKnell, Gregory 08 1900 (has links)
Engaging in muscle strengthening activities (MSA) as part of a physical activity program offers health benefits. Although the merits of physical activity are well documented, many adults fail to meet appropriate levels as recommended in the 2008 Physical Activity Guidelines for Americans (PAGA). To get a more complete understanding on an individual's physical activity behaviors, the Tracking Resistance Exercise and Strength Training (TREST) internet based survey was developed. The purpose of the current study was to determine the test-retest reliability of TREST items. Additionally, the prevalence of participants meeting the 2008 PAGA was reported by gender. The survey was completed approximately two weeks apart by 224 (52% male) undergraduate kinesiology students. Analysis of the survey items presented TREST as a reliable instrument in assessing an individual's physical activity behavior with a focus on MSA. Among the convenience sample of 445 participants (56% male) that completed the survey in assessment #1, 73% met the 2008 PAGA minimum recommendations for MSA (>=2 days/week) and aerobic activity (>= 150 min MVPA). A more complete MSA and MVPA criteria was established (requiring MSA of all seven major muscle groups) and only 32% of participants met this guideline. In general, men engaged in aerobic exercise and MSA more than women. These results cannot be generalized due the age, activity level, and education of the study's participants. Future studies should investigate the validity of TREST items among a sample of varying fitness levels, races/ethnicities, ages, and educational levels.
Understanding and Testing the Link Between Motivational Interviewing and Self-Compassion Through Physical Activity CounsellingPastore, Olivia Lena 04 September 2020 (has links)
Background: Motivational Interviewing (MI) is an accepting and compassionate collaborative counselling style that has been linked with various desirable client outcomes. However, its association with self-compassion (SC), an important psychological resource is unknown. One context in which this relationship can be studied is in Physical Activity Counselling (PAC), which is an MI-based intervention that has been found to enhance motivation towards physical activity (PA) and PA behaviour, as well as reduce depressive symptoms. However, no hypothesized link has ever been made between MI and SC and no research has been done on the impact of MI-based PAC onto SC or has investigated SC’s relationship with PA within PAC. Purpose: Article 1: To explore the link between MI and SC. Article 2: To test this proposed association by investigating the impact of a MI-based intervention, specifically through PAC, over time on (1) self-compassion and its subcomponents, and (2) PA and its intensities. A third and fourth purpose were to (3) examine whether any improvements in SC or PA variables were continued at 1-month follow-up and lastly, (4) study the relationships between SC and PA variables over time in university students and employees receiving PAC. Methods: Article 1: This article was a commentary paper that rationalized the hypothesized link between MI and SC. Article 2: This article reports results from a study which used a repeated-measures experimental study design, whereby forty university students and employees filled out online validated self-report questionnaires assessing SC and PA before (baseline), immediately after (endpoint), and 1-month after (follow-up) receiving individualized PAC sessions. Participants reached out to PAC mostly on their own or were referred by other programs on campus. Fidelity checks showed that PAC counsellors were accepting and compassionate. Results: Article 1: A hypothesized link was made between MI and SC, such that the accepting and compassionate spirit of MI, as well as certain content-based techniques used within could help to foster a self-compassionate mindset within the receivers of MI. Article 2: Paired-samples t-tests and multivariate analysis of variance tests revealed that there were significant moderate-to-large increases in total SC, self-kindness, and total, moderate, and strenuous PA from baseline to endpoint. There was also a significant large effect for decreases in self-judgement and isolation from baseline to endpoint. All changes appeared to be continued at 1-month follow-up. Lastly, results revealed that common humanity at baseline positively influenced moderate PA at endpoint. Conclusion: This provides a strong case for the link between MI and SC and provides preliminary evidence to support the positive impact of MI, specifically through PAC, onto SC and PA variables, as well as their relationship over time. Future research is recommended in order to ascertain these findings and practitioners are encouraged to show high acceptance and compassion while assisting individuals with PA behaviour change.
THE EFFECT OF WEIGHT LOSS AND EXERCISE ON CARDIOVASCULAR STRUCTURE AND FUNCTION IN CLASS II AND III OBESE WOMENVerba, Steven 18 August 2011 (has links)
Introduction: Obesity is a public health concern in its association with various comorbidities, especially cardiovascular disease. Negative structural and functional changes of the left ventricle are associated with obesity and research is conflicting as to the effect of diet-induced and diet plus exercise-induced weight loss in Class II and III obese adults. Purpose: The purpose of this study was to examine effect of diet-induced or diet plus exercise-induced weight loss on cardiac structure and function in Class II and III obese women. Methods: 24 healthy, sedentary, obese women (BMI: 35.0 to 45 kg/m2; Age: 45.4 + 6.9yrs.) underwent a 12-week diet and exercise intervention: caloric restriction alone (DIET), caloric restriction plus aerobic training (DIET+AT), and caloric restriction plus resistance training (DIET+RT). Subjects reported to UPMC Presbyterian Hospital to undergo Cardiac MRI to measure left ventricular mass (LVM), myocardial fibrosis (Ve), end diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF). Results: 18 out of 24 subjects completed the intervention. 16 out of 24 completed 12 week Cardiac MRI at UPMC Presbyterian. Body weight significantly decreased across all treatment groups (~4.5kg lost, p=0.001). Subjects in the DIET group had significantly greater reduction in LVM (-7.2 ± 3.9g) than the DIET+AT (2.3 ± 4.7g) and DIET+RT (-0.2 ± 3.5g) groups (p=0.007). Subjects in the DIET+RT group had a significantly higher Ve score at 12 weeks (27.9 ± 1.5%) than subjects in the DIET+AT (26.5 ± 1.4%) and DIET (24.0 ± 0.8%) groups (p=0.010). There were no significant changes in EDV, ESV, or EF at 12 weeks between groups (p>0.159). Conclusions: In conclusion, only LVM in the DIET group and Ve in the DIET+RT showed statistical changes from baseline. Further investigations into the effect of weight loss and exercise on cardiac structure and function in Class II and III obese adults are warranted to expand upon the results of this investigation.
Justice, Blake D.
25 August 2011
Introduction: The role that inflammation plays in the atherosclerotic disease process is well established. Obesity is coupled with a state of chronic inflammation and is associated with increased circulating inflammatory markers including C-Reactive Protein. Purpose: The purpose of this study was to evaluate the additive effect of aerobic or resistance exercise training to caloric restriction for weight loss on high sensitivity C-Reactive Protein changes compared to dietary restriction alone in class II and class III obese individuals. Methods: 24 healthy, sedentary, obese women underwent a 12-week diet and exercise intervention: Caloric restriction weight loss program with no exercise (DIET); Caloric restriction with aerobic endurance training (DIET+AT); and Caloric restriction with resistance training (DIET+RT). Blood was drawn at baseline and 12-weeks and assayed for hs-CRP. Results: Weight was decreased significantly in all groups in the intervention. Hs-CRP was unchanged at 12-weeks.Conclusions: In conclusion, this investigation was successful in producing weight loss, BMI decreases, decreases in body fat percentage, and positive changes in fitness markers, though no changes in hs-CRP were associated with weight loss or weight loss with exercise. Further investigations into the influence of weight loss and exercise on CRP levels among Class II and Class III individuals should be completed to examine and expand upon the results observed in this study.
07 August 2012
The Heart Healthy Kids (H2K) program examines peer mentoring and physical activity of grades 4, 5, and 6 students (n=808 children from 10 schools). This sub-study qualitatively explored the peer mentoring experience, using the social ecological model to examine the experience from multiple perspectives. A qualitative description design was used, with a phenomenological approach to data analysis. Three focus groups were conducted with 17 children (5 male, average age: 10.6 years) at 3 of the H2K intervention schools. Six additional individual interviews were conducted with 1 parents and 1 teacher from each focus group school (all female). Thematic analysis was conducted. Emergent themes included that peer mentors were perceived as “encouragers of physical activity”, “helpers and supporters”, “organizers and administrators”, and “expanders of social networks”. Results suggest that reframing physical activity programs to promote physical activity in the context of fun, unstructured, social engagement, especially those that employ peer mentoring, may be more successful. This research contributes to development of future programs and research, and knowledge of the applicability of peer mentoring in influencing child physical activity levels.
26 September 2007
Background: A beneficial effect of physical activity on the risk of cancer at several sites has been consistently observed. Biologic mechanisms that may underlie this relationship are not well understood. A potential mechanism explaining this relationship for some cancer sites is the influence of physical activity on methionine-homocysteine biosynthesis. High levels of total plasma homocysteine concentration (tHcy) indicate a breakdown in this biochemical process. This cycle’s influences on DNA methylation and endogeneous agents involved in oxidative stress are potential mechanisms linking methionine-homocysteine biosynthesis to cancer risk. This research is nested within a larger cross sectional study of healthy volunteers recruited from centers in Ontario and Nova Scotia aimed at understanding modifiable risk factors for cancer. Purpose: This research sought to elucidate the relationship between physical activity and tHcy level. Methods: The target population was healthy male and female subjects aged 20-50. Participants donate a 12ml blood sample after an overnight fast for analysis of tHcy and dietary factors and complete a questionnaire including a physical activity profile for the past month (adapted from the International Physical Activity Questionnaire [IPAQ]) and established predictors of tHcy level such as coffee and alcohol consumption. Multiple linear regression is used to model the relationship between tHcy and physical activity measures while controlling for potential confounders. Results: Analysis on 171 participants has been carried out. Mean tHcy for five quintiles of physical activity (from lowest physical activity score to highest) were found to be 8.40μmol/L (7.76-9.05), 8.60μmol/L (8.00, 9.22), 9.24μmol/L (8.66, 9.81), 8.23 μmol/L(7.64, 8.82), and 8.70μmol/L (8.09, 9.31). Conclusions: The findings of this research do not support a relationship between physical activity and total plasma homocysteine concentration. Results of this study suggest that homocysteine is not a mediating factor for the relationship observed between physical activity and cancer. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2007-09-25 11:19:23.321
School and neighbourhood recreational environments and their impact on physical activity participation among Canadian youthNichol, Marianne Elizabeth 27 May 2008 (has links)
Background: Less than half of Canadian youth meet recommended levels of physical activity. This is of concern given the health burden associated with physical inactivity. With the limited success of physical activity interventions, research has begun to focus on how physical and sociocultural environments affect physical activity. Investigation of school and neighbourhood characteristics that facilitate physical activity may identify environmental changes that could increase participation among adolescents. Objectives: The objectives of the two studies comprising the thesis were to examine, among youth in grades 6 through 10: 1) the association between school recreational characteristics and physical activity during free-time and class-time at school, and 2) the effects of perceptions of neighbourhood safety and availability of parks and recreational facilities on physical activity participation outside of school. Methods: Data from the 2006 Canadian Health Behaviour in School-Aged Children Survey (HBSC) were analyzed. Multilevel logistic regression was employed to quantify associations between school and neighbourhood characteristics and physical activity. For the first study, student responses to school-time physical activity scales were dichotomized (≥ 2 vs. <2 hours/week). A cumulative index that considered together policies, varsity and intramural athletics, presence and condition of fields, and condition of gymnasia was constructed based on principals’ reports. In the second study, physical activity outside of school was dichotomized (≥ 4 vs. <4 hours/week). A scale of individuals’ perceptions of safety was constructed. The number of parks and recreational facilities within a 5 km buffer of schools was abstracted from a geographical information system. Results: Objective 1. School recreational features were modestly positively related to adolescents’ physical activity at school, particularly that occurring during free-time. The cumulative effect of school recreational features exerted a stronger effect than any single feature. Objective 2. Perceptions of safety were associated with students’ physical activity, whereas increased availability of parks and recreational facilities neither prevented nor promoted physical activity. Conclusions: Objective 1. High levels of recreational support at schools might promote physical activity among young people. This could inform educational policies and support funding of school recreational opportunities. Objective 2. Improving perceptions of safety might promote physical activity participation among youth. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2008-05-22 15:44:36.541
Physical activity, sedentary behaviour and sleep: associations with cardiometabolic risk in abdominally obese men and womenMCGUIRE, McGuire, Karen Ashlee 18 May 2011 (has links)
Current guidelines suggest that physical activity must be performed at a moderate-to-vigorous intensity (MVPA) and accumulated in bouts of at least 10 consecutive minutes to elicit improvement in cardiorespiratory fitness (CRF). In the first study we sought to determine whether the duration and intensity of objectively measured incidental physical activity (IPA; activity performed below the designated threshold) was associated with CRF in abdominally obese, inactive men (n=43) and women (n=92). Secondary analyses examined the associations between light physical activity (LPA), sporadic moderate physical activity (MPA; accumulated in <10 minute bouts), and CRF. Both duration and intensity of IPA were positively associated with CRF among inactive, abdominally obese adults. Sporadic MPA, but not LPA, was an independent predictor of CRF. Whereas some observations suggest that sedentary behaviour (SED) is negatively associated with health outcomes, other evidence fails to support this notion. The primary aim of the second study was to clarify the relationships between SED, LPA, and MVPA with 2-hour glucose and insulin resistance in inactive adults (43 men, 92 women) with abdominal obesity. Secondary analyses examined the association between SED, LPA, MVPA and other common cardiometabolic risk factors. Neither SED nor the physical activity variables were associated with 2-hour glucose or insulin resistance. SED was not associated with any cardiometabolic risk factor; with the exception of blood pressure, LPA was not associated with any cardiometabolic risk factor; and MVPA was independently associated with total cholesterol and triglycerides. Whether IPA is associated with abdominal obesity is unknown. The purpose of study three was to determine the association between IPA and abdominal adipose tissue depots (visceral adipose tissue and subcutaneous adipose tissue) in inactive men (n=42) and women (n=84). Secondary analyses examined the associations between SED, sleep duration, and caloric intake with abdominal obesity. IPA was not associated with any measure of abdominal obesity, nor was LPA. After control for age and sex, MPA was negatively associated with visceral adipose tissue. SED and sleep duration were not associated with abdominal obesity. Caloric intake was not associated with abdominal obesity after control for age and sex. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2011-05-17 13:33:52.518
16 June 2011
The purpose of this study was to determine if, after adjusting for the contribution of exercise dose, exercise intensity was associated with the improvement of insulin sensitivity. Abdominally obese, sedentary men (n = 16, [mean±SD] age: 45.0±7.5 yr; waist circumference: 108.6±5.3 cm) and women (n = 18, [mean±SD] age: 42.3±6.2 yr; waist circumference: 100.1±8.2 cm) performed daily, supervised exercise for 3 and 4 months, respectively. Exercising at a self selected exercise intensity, men were required to expend expended 700 kcal per session and women 500 kcal per session. Exercise intensity and dose were determined using heart rate and oxygen consumption data obtained from repeated graded exercise tests. Insulin sensitivity was determined by hyperinsulinemic euglycemic clamp. Insulin sensitivity improved in both men and women (change score: men = 7.2±5.4 mg/kgskm/min, women = 5.8±7.1 mg/kgskm/min) (p < 0.05). Exercise intensity was associated with the improvements in insulin sensitivity in men (unstandardized regression coefficient (β) = 0.43, p = 0.02). Adjusting for exercise dose, the change in abdominal adipose tissue (AT), or the change visceral AT did not alter this association (p < 0.05). Exercise intensity was not associated with the improvement of insulin sensitivity in women (β = - 0.11, p = 0.7). Adjusting for exercise dose, the change in abdominal or visceral AT did not change the association in women (p > 0.05). Our findings suggest that exercise intensity is independently associated with the improvement of insulin sensitivity in abdominally obese men but not women. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2011-06-13 19:56:40.465
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