Thesis (MPH)--University of Limpopo, 2010. / Despite an increased focus on adolescents’ diet, nutrition and exercise in South Africa over the past years, their dietary intake remains a major cause for concern, with increasing numbers consuming high fat and high sugar foods on a daily basis. The consumption of these foods may be due to industrialization as processed foods are less expensive, easily accessible and do not require time and energy in their preparation. Health education intervention can play a major role in spreading health messages on prevention and management of non-communicable diseases. Health education should start at school, as many personal habits and life-style choices are made early in life. The objectives of the study were to identify and describe learners’ knowledge and practise of a healthy diet, daily nutritional requirements and the importance of regular exercise. This is a cross-sectional survey using a self-administered questionnaire with closed and open-ended questions. Tswaing High School was used as a study site and the sample comprised all learners who were present on the day of study and who had submitted the consent form from their parents (485 learners or 69.3%). Seventy-seven percent of learners scored under 50% on the test that was administered and only 23% of learners had a satisfactory knowledge of diet, nutrition and physical activity, and 41.3% of the respondents reported that they were sedentary for hours. Learners of Tswaing High School do not possess adequate knowledge of nutrition and diet. The government departments such as education, sports, arts and culture, and health should implement vi programmes that will inform learners about the importance of nutrition, diet and exercise in their lives.

Thesis (M Med (Family Medicine))--University of Limpopo (Medunsa Campus), 2010. / Abundant literature supports the beneficial effects of diet and exercise recommendations for improving and maintaining glycaemic levels of people with type 2 diabetes mellitus. Patient adherence to therapeutic lifestyle measures is notoriously difficult to initiate and sustain; however, reason for non-adherence amongst diabetes population is very complex and multi-faceted in nature. Objectives To determine rates of non-adherence and reasons/barriers for not adhering to diet and exercise recommendations amongst type 2 diabetes mellitus patients attending Extension II clinic in Gaborone, Botswana. Summary of methods Design: descriptive cross-sectional study using self administered questionnaire Setting: Extension II clinic, a public family practice in Gaborone, Botswana. Study population: Consenting adults diagnosed with type 2 diabetes mellitus, aged 30 years or older, diagnosed 2 or more years and on clinic care. Sample selection: Convenience sampling method was used to select 35 subjects per month, over a period of three successive months and a total of 105 participants were recruited into the study, made up of 44 men and 61 women. Results 104 correctly filled questionnaires were included in the data analysis, of which, 59% were female. Estimated rates of non-adherence to diet and exercise were 37.4%; 95% CI, 27.7 – 46.3% and 52%; 95% CI, 42.4 – 61.6% respectively. The main perceived reasons for non-adherence to diet were granting self-permission (36.5%), lack of information (33.3%), eating out (31.7%), financial constraints (28.8%) and poor self control (26.9%); while the main perceived reasons for non-adherence to exercise were lack of information (65.7%), exercise as potentially exacerbating illness (57.6%), lack of exercise partner (24.0%), specific locations away from home (18.0%), and winter weather (15.4%). The overall reasons for not adhering to diet and exercise include lack of moral and emotional supports from the spouse (54.1%), family members (44.8%), and friends (58.7%). 95% and 67.3% of the participants had reported that diet and exercise respectively could improved and maintained their diabetic control. Conclusion Non-adherence to diet and exercise recommendations amongst type 2 diabetes patients is far more prevalent and no particular single reason could be attributed to poor adherence to either diet or exercise recommendations, rather a combination of many factors.

This thesis investigated the effect of exercise and the exercise setting on self-concept in the context of older women. Very little research in this area has focused on older women. At the same time it attempted to identify possible mechanisms underpinning exercise-induced change in self-concept, including the effect of the group and change in real and perceived body condition and real and perceived fitness. Adherence issues and the hierarchical structure of self-concept were examined in an exploratory manner. An extensive literature review was undertaken. It concluded with a preliminary exercise-self-concept model which would be used to explain and evaluate the thesis??? hypotheses. Two studies were undertaken. Study 1 validated the English version of the Self-perception in Exercise Questionnaire (SPEQ) (Sorensen, 1999) and examined relationships between exercise status, age, body size, and physical self-perceptions in a sample of older Australian women. The SPEQ was found to be a valid and reliable instrument to be used in Study 2 to measure self-perceptions relevant to exercise in older Australian women. Study 2, a randomised controlled trial, examined the effect of exercise and the exercise setting on older women???s self-concept. It comprises the main body of work for this thesis. It compared a group of older women exercising together in a group to a similar group of women who performed exactly the same exercise alone. Then both groups were compared to a similarly motivated group of women who did not exercise, but were waiting to start an exercise program. Using a pre-posttest design it measured exercise-induced change in self-concept, selfperceptions, satisfaction, and 13 physiological measures. Following a 12-week exercise treatment, the older women who walked regularly either alone or in a group thrice weekly experienced significantly improved total, physical, and social self-concept, more positive perceptions of their body and fitness, increased satisfaction with self and with life in general, and improved aerobic fitness compared to controls. When the three experimental conditions were compared, however, these outcomes were significant only for group exercise compared to controls; not for alone exercise compared to controls. Of greater importance, when the two exercise settings, walk alone and walk in a group, were compared, the women who walked in a group experienced significantly improved physical self-concept, satisfaction with life, and more positive perceptions of their body and fitness compared to the women who walked alone. Unexpectedly, aerobic fitness also increased significantly for the women who walked in a group relative to controls, but not for the alone walk condition. Taken together these findings suggest group exercise offers considerable psychological and aerobic fitness benefits to older women. These are valuable and unique findings. They are reinforced by the high adherence (91%) and participation rates (95%) achieved in the walk trial. Partial support was found for the proposed exercise-self-concept model and the hierarchical structure of self-concept was demonstrated. Perceived change accounted for more of the variance in self-concept than real body and fitness change. Effect sizes were larger for certain physical self-perceptions than for global self-concept. In conclusion, this thesis has extended current knowledge of exercise effects on selfconcept to older women, added a systematic exercise-self-concept review, added a useful instrument for measuring older women???s self-perceptions in exercise in future studies, and added to current knowledge of mechanisms underpinning improved self-concept following exercise. Exercise, moderate-intensity walking, was found to positively and significantly affect older women???s self-concept. The exercise setting differentially affected older women???s selfconcept; effects were significantly greater when the exercise was performed in a group with similar others. The group exercise setting and its effect on self-perceptions is suggested as a possible mechanism underpinning the positive exercise-self-concept association.

The ability to perform well during the sprint start and early acceleration phases of sprint running is critical. Many forms of training interventions are utilised to give a sprinter a competitive edge over their opponents in these particular phases. Despite this fact, there has been limited research on the technical and power type training strategies appropriate to improve sprint kinematics and the associated sprint performance in the sprint start and early acceleration phases. PURPOSE: To determine the best sprint start and early acceleration phase kinematic determinants, investigate the effect that load has on the kinematics of the sprint start and early acceleration performance and to determine how various physical characteristics may influence both resisted and unresisted sprint running. METHODS: Ten male track sprinters (mean ± SD: age 20 ± 3 years; height 1.82 ± 0.06 m; weight 76.7 ± 7.9 kg; 100 m personal best: 10.87 + 0.36 s {10.37 - 11.42 s}) attended two testing sessions. The first session required the athletes to sprint twelve 10 m sprints from a block start under unresisted and resisted (10% & 20% body mass) sled conditions. The second session required each athlete to complete an anthropometric assessment (height, mass, 3 bone lengths, 2 bone widths) and a variety of vertical (squat jump, countermovement jump, continuous straight legged jump) and horizontal (single leg hop for distance, single leg triple hop for distance) jump tests (3 trials each). Centre of gravity, joint and segment kinematics were calculated from 2D analysis utilising a kinematic analysis system (Ariel Performance Analysis System, U.S.A.). Means and standard deviations are presented for kinematic and performance measures. Pearson's product-moment correlation coefficients were employed to establish relationships between sprint start (block) performance variables and 10 m sprint performance. A linear regression analysis was used to quantify the relationships between the dependent variables (start performance and 10 m sprint time) and selected kinematic independent variables. ANOVA's with repeated measures were used to determine if there was a significant interaction between the kinematics under the various loaded conditions. A stepwise multiple regression and linear regression analysis were used for the prediction of unresisted and resisted sprint times from anthropometrical and functional performance measures. RESULTS: Mean horizontal block acceleration was identified as the start performance variable with the strongest relationship to 10 m sprint time. The most significant kinematic predictors of mean horizontal block acceleration were a large horizontal block velocity, short start time, and low thigh angle of the front block leg with respect to the horizontal at block takeoff. Sprint time over 10 m was best predicted by a large mean horizontal block acceleration (sprint start performance), increased angle of the front arm shoulder at step takeoff, and increased angle of front upper arm at step takeoff. Sprint start kinematics significantly altered as a result of resisted sled towing were start time (increase) and push-off angle from the blocks (decrease). Step length, stance time and propulsion time significantly increased, whereas flight time and flight distance significantly decreased under loaded conditions. A load of 20% body mass was revealed to be the better training load to utilise during resisted sled sprinting, especially for athletes who performed faster than 2.10 s for a 10 m sprint from a block start. The countermovement jump exercise was a strong predictor of both 10 m and 100 m sprint time. The continuous straight legged jump test was revealed to be a good predictor of resisted sprints over 10m.CONCLUSION: Consideration should be given to the technical training aspects of sprint start performance and forceful arm movements during step takeoff for improving sprint start and early acceleration sprint performance from starting blocks. These technical training aspects should also be supplemented with resisted sled towing with a load of 20% body mass and countermovement jump training to improve sprint ability.

The phase of greatest acceleration (0-30 metres) during sprinting is thought to be critical for success in many sporting situations. Methods for improving acceleration phase performance are therefore an important area of study for conditioners and sports scientists. Typically a variety of resistance training techniques are used to improve strength and power of the lower limb musculature that is important to sprinting performance. One such technique is resisted sprinting which involves the use of apparatus such as weighted vests and sleds to provide movement specific overload to athletes. The purpose of this thesis was primarily, to compare sprint times, step variables and joint kinematics when sprinting with a vest loaded at 15% and 20% of the athlete's body mass and towing a sled with 15% and 20% of body mass. A secondary aim was to examine the effect of a six-week training program utilising resisted sprinting on acceleration phase performance in three athletes.In the first study, 20 semi-elite subjects performed five 30-metre sprints: one unloaded sprint, two sled sprints loaded at 15% of their body mass and 20% of their body mass, and two vest sprints with the same loads relative to body mass. Each sprint was videoed in the sagittal plane at five, 15 and 25 metres from the start of the 30-metre sprint and times were recorded at 10 and 30-metres using timing lights. Video data were digitised and the following step variables were calculated: step length, step frequency, stance phase duration and swing phase duration. Stance phase angles of the trunk, thigh, knee and ankle were also calculated. Step length, step frequency and swing phase duration during vest and sled sprinting were found to decrease significantly (P<0.05) when compared to unloaded sprinting values. Stance phase duration during vest and sled sprinting increased compared to unloaded sprinting values (P<0.05). Additionally, sled towing displayed significantly greater (P<0.05) trunk flexion at foot strike and toe-off, and significantly greater (P<0.05) knee flexion at foot strike than both the unloaded and vest sprinting conditions. Sled towing also induced significantly greater thigh extension at toe-off compared to the vest conditions (P<0.05). Thus the addition of load to the athlete via vest sprinting and sled towing may influence performance in different ways, and hence the objective of the athlete should be considered when choosing which of these techniques to use.In the second study, a single subject research design was utilised to assess whether sled towing and vest sprinting resulted in changes in performance over a six-week period of training. In this study, three subjects trained twice a week for six weeks using resisted sprinting. Subjects were randomly assigned to sled training, vest training or combination training (one training session a week with each apparatus). Subjects were tested at baseline, after three weeks of training and after six weeks of training for 10 and 30-metre sprint times and selected step variables (step length, step frequency and stance phase duration). Data analysis involved both visual analysis of graphed data and statistical analysis using the two standard deviation band method. The combination training subject improved performance over both 10 and 30 metres. Step variable data were inconclusive regarding the mechanisms behind these improvements. Neither sled towing nor vest sprinting resulted in significant improvements in performance. The results indicated that the use of both training apparatus in unison may be required in order to improve performance during the acceleration phase of sprinting.

Building upon Deci and Ryan's (1985, 1991) self-determination theory as well as previous empirical work on motivation, the present study was designed to develop a multifaceted 31-item Exercise Motivation Scale (EMS). A series of pilot studies were first conducted in order to generate the 31 scale items. The EMS was then administered to male and female college students (N=592) who participated in various exercise activity classes offered through university physical activity programs. Using structural equation modeling methodology, evidence for a robust factor structure, subscale reliabilities, and convergent and discriminant validity was sought for the proposed eight facets of the exercise motivation construct. These facets included amotivation, external regulation, introjected regulation, identified regulation, integrated regulation, intrinsic motivation to learn, intrinsic motivation to accomplish things, and intrinsic motivation to experience sensation. Results provided adequate evidence for the a priori hypothesized EMS factor structure, and acceptable subscale reliability estimates. Further analyses on the EMS structural relationships revealed a simplex pattern of the self-determination continuum underlying the various motivational orientations assessed by the EMS. Finally, selected antecedents and consequences of exercise motivation showed that the EMS facets had nomological validity and depicted differential relationships with the various antecedents and consequences examined. These results provided initial empirical support for the applicability of self-determination theory in the context of exercise, and suggested a multifaceted approach to the conceptualization of exercise motivation. / Graduation date: 1996

Graduation date: 1995

Thesis (M.S.)--Montana State University--Bozeman, 2006. / Typescript. Chairperson, Graduate Committee: Mary P. Miles. Includes bibliographical references (leaves 62-66).

Whereas clinical professionals and the general public recognize exercise in moderate amounts as an important component of a healthy lifestyle, researchers have noted that when taken to an excessive level, exercise may become addictive. Usually considered rare in the broad exercising population, risk for exercise addiction has been found to be more prominent among certain specialized groups, such as runners. This study investigated the risk for exercise addiction in a unique group of endurance athletes-Sprint-, Olympic-, Half-Ironman, and Ironman-distance triathletes. The sample consisted of 1285 male and female triathletes, ranging in age from 18 to 70 years old, recruited through the electronic newsletter of a national triathlon organization. During the past year participants completed at least one triathlon of Sprint-, Olympic-, Half-Ironman-, and/or Ironman-distance, or were in training for one. To measure the risk for exercise addiction, participants completed an online questionnaire, comprising the six items of the Exercise Addiction Inventory (Terry, Szabo, & Griffiths, 2004), six items added by the investigator, and a demographics section. Results indicate that approximately 20% of triathletes are at risk for exercise addiction, 79% are committed exercisers who exhibit some symptoms of exercise addiction, and 1% are asymptomatic. Results also demonstrate that female triathletes are at greater risk for exercise addiction than male triathletes. Training for longer distance races (e.g., Olympic-, Half-Ironman-, and Ironman-) put triathletes at greater risk for exercise addiction than training for shorter races. No significant association exists between the risk for exercise addiction and either the number of years of participating in the sport or the length of training sessions. However, as the number of weekly training hours or the number of weekly training sessions increases, so does a triathlete's risk for exercise addiction. Results demonstrate that triathletes have a lower than anticipated risk for exercise addiction, yet a higher risk than the general exercising population. Because at-risk triathletes need greater clinical attention, further research should be conducted to help clinicians develop enhanced awareness and appropriate interventions.

Thesis (M.A.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 9, 2007) Includes bibliographical references.