Objectives: The aim of this study was to determine associations between physical activity (PA), blood pressure (BP) and renin in urban black Africans. Methods: The study sample included 137 urban African males (N=68) and females (N=69) (aged 41.53 ± 8.13 and 44.16 ± 7.37 years, respectively), from the North West Province, South Africa. Anthropometric measurements, ambulatory blood pressure and energy expenditure were determined. Actical® accelerometers were used to determine energy expenditure (METS) over a 24 hour period. Fasting blood samples were used to determine fasting blood glucose, serum cotinine (COT), gamma–glutamyl transferase (GGT) and plasma renin. Results: A greater percentage (64%) of African males were hypertensive compared to African females (33.33%). SBP (p<0.001) and DBP (p<0.001) were significantly higher in males than females. Female subjects were more obese (32.00±7.75 kg/m2) whereas males demonstrated an overweight status (27.28±5.86kg/m2). Male subjects displayed overall higher lifestyle risks (BP, smoking, alcohol consumption, HIV–status) than females. Multivariate regression analyses demonstrated an inverse relationship between BP and renin in both males and females, but no associations existed between renin and physical inactivity. Conclusion: PA appeared not to buffer elevated blood pressure in this specific African sample, as no significant associations supported this hypothesis. The results confirm that black Africans display lower renin levels associated with elevated blood pressure. Furthermore, low renin and physical inactivity was not related to indicate elevated BP through elevated SNS activity. / Thesis (M.Sc. (Biokinetics))--North-West University, Potchefstroom Campus, 2012.

Modern life, which is characterised by automation and mechanisation, causes laziness and inactivity in people all over the world. It in essence deprives one of movement, which negatively affects man and his body. Chronic illnesses caused by an inactive lifestyle lead to unnecessary deaths, which again impacts negatively on the community as a whole. The South African Police Service (SAPS) has far from escaped this worldwide phenomenon. It is, in fact, experiencing an abnormally high death rate, which can be linked directly to police officers’ lifestyle. This study has proven that the average police officer is in extremely poor physical condition, and that this is in all probability the cause of the unusually high natural death rate as well as the high incidence of suicide among SAPS members. The primary objective of this study is the justification of a physical maintenance programme for law enforcement officers. For this programme to be successful, it has to: (i) be relatively inexpensive and provide easily accessible facilities; (ii) be in line with critical physical job requirements; (iii) contribute directly to the maintenance of job-oriented fitness; (iv) include a section that is solely tasked with the physical maintenance of the officers; and (v) form part of the SAPS’s policy on sport. The results of this study show the dire necessity of the immediate implementation by SAPS management of the suggested physical maintenance programme. / Thesis (DPhil (Human Movement Science))--University of Pretoria, 2003. / Biokinetics, Sport and Leisure Sciences / unrestricted

Obesity is affecting an increasingly larger proportion of adolescents in the world, and this can be attributed to low resting metabolic rate (RMR) as well as reduced physical activity (PA) levels. Little is known about objectively determined habitual PA and RMR in 16 year old African adolescents. The purpose of this study is twofold. Firstly, to determine the objectively measured PA status of adolescents and secondly, to determine the relationship that exists between RMR and PA in 16 year old adolescents. Two hundred and twenty six (226) adolescents aged sixteen (16) wore the Actiheart® monitor, combined accelerometry and heart rate for seven (7) consecutive days. Six high schools were recruited to take part in the study: two from town (high socio-economic status) and four from the township (low socio-economic status) of the Potchefstroom area of the North West Province of South Africa. Times spent in moderate to vigorous physical activity, physical activity counts per minute (CPM), total energy expenditure (TEE), active energy expenditure (AEE) and physical activity levels (PAL) were assessed using the Actiheart®. The participants’ RMR was measured by indirect calorimetry using the Fitmate Pro (Cosmed, Italy). All data analyses were performed with the SPSS Version 20 software (IBM SPSS, II). The descriptive statistics (mean and standard deviations) as well as independent t-tests and Mann-Whitney U test were performed to determine differences between ethnicity and genders and to calculate practical significance. A Type I error rate of p ≤ 0.05 was used for statistical significance. To investigate the relationship between RMR and physical activity regression analysis was performed with adjustment for gender, race and fat free mass. Results: Significantly higher PAL (1.57 ± 0.15) were determined in girls compared to boys (PAL = 1.41 ± 0.10). Black adolescents indicated significant higher PAL (1.53 ± 0.14) compared to white adolescents (1.45 ± 0.16). On average, regardless of race or gender, the participants were more active on weekdays than weekends. The current study shows that girls spent more minutes/day in moderate to vigorous physical activity (MVPA) than the boys. The results show that 16.4% of the study sample was either overweight or obese. After adjustment for gender, ethnicity and FFM, linear regression between RMR and moderate-to-vigorous PA yielded an r2 = 0.46 (p ˂ 0.05.) Conclusion: Objectively determined PA of adolescents in South Africa indicates that only one third of adolescents are meeting the recommended 60 minutes of daily MVPA. Gender and race specific interventions are needed to increase habitual physical activity levels in adolescents. Given the fact that the studied sample did not meet recommended daily physical activity and the adverse effect of inactivity and chronic diseases of life style, urgent strategies to inculcate the culture of regular physical activity as a preventative measure of chronic diseases of life style are needed. Behaviour that is carried on into adulthood is established during adolescence. Civic health efforts should focus on encouraging adolescent involvement in regular moderate-to-vigorous PA, which will subsequently increase RMR and lower the risk of the development of non-communicable chronic diseases such as obesity. Further local research is needed to confirm the association between RMR and PA in the local population. / Thesis (MSc (Biokinetics))--North-West University, Potchefstroom Campus, 2013.

Television viewing is one of the most easily modifiable causes of obesity among children. The purpose of this study was to determine the relationship between body composition and TV viewing among adolescents attending high schools in the Tlokwe municipality area of the North West province of South Africa. A cross-sectional study design which is part of the Physical Activity and Health Longitudinal Study (PAHLS) was followed on 154 learners (58 boys and 96 girls) who were aged 14 years in the Tlokwe municipality area. All the learners underwent anthropometric measurements of height, weight, and two skinfolds (triceps and subscapular skinfolds). Percentage body fat (%BF) was calculated from the two skinfolds according to Slaughter‟s et al. (1988) equation. Children were classified into three groups (viz. normal, overweight and obese) according to BMI cut-off point suggested by Cole et al. (2000). Pearson correlation coefficients were used to determine the relationship between television viewing and body composition. The results show respectively high prevalence of overweight and obesity in girls (10.4%; 6.3%) as compared to the prevalence of 5% overweight in boys. With regard to TV viewing, the results show that 54% of the total group watch TV more than two hours a day, while only 11% watched TV less than one hour a day. The results show that the group that watches TV for more than 3 hours had high BMI (21.27kg/m²) and body mass (51.54kg). The group that watches TV for 1-2 hours had low BMI (18.36kg/m²) and body mass (44.79kg). There was a statisitcal significant relationship between BMI and body mass (p=0.001). A significant positive relationship between body mass and TV viewing (r=0.56; p=0.05) in overweight group was found, whilst in the obese group strong significant positive relationship was observed between percentage body fat and TV viewieng (r=0.94; p=0.01). It can be concluded that girls were more overweight and obese respectively as compared to the boys. Furthermore, both boys and girls had high percentages of TV viewing for more than two hours a day. In addition, the results indicated that adolescents who watched TV more than 3 hours are heavier and fatter. Therefore, it is recommended that parents and educational heads should encourage periods of daily physical activity. In addition, it is also important that parents play a more positive role in limiting the amount of hours their children spent watching television. / Thesis (MA (Biokinetics))--North-West University, Potchefstroom Campus, 2013.

Obesity is affecting an increasingly larger proportion of adolescents in the world, and this can be attributed to low resting metabolic rate (RMR) as well as reduced physical activity (PA) levels. Little is known about objectively determined habitual PA and RMR in 16 year old African adolescents. The purpose of this study is twofold. Firstly, to determine the objectively measured PA status of adolescents and secondly, to determine the relationship that exists between RMR and PA in 16 year old adolescents. Two hundred and twenty six (226) adolescents aged sixteen (16) wore the Actiheart® monitor, combined accelerometry and heart rate for seven (7) consecutive days. Six high schools were recruited to take part in the study: two from town (high socio-economic status) and four from the township (low socio-economic status) of the Potchefstroom area of the North West Province of South Africa. Times spent in moderate to vigorous physical activity, physical activity counts per minute (CPM), total energy expenditure (TEE), active energy expenditure (AEE) and physical activity levels (PAL) were assessed using the Actiheart®. The participants’ RMR was measured by indirect calorimetry using the Fitmate Pro (Cosmed, Italy). All data analyses were performed with the SPSS Version 20 software (IBM SPSS, II). The descriptive statistics (mean and standard deviations) as well as independent t-tests and Mann-Whitney U test were performed to determine differences between ethnicity and genders and to calculate practical significance. A Type I error rate of p ≤ 0.05 was used for statistical significance. To investigate the relationship between RMR and physical activity regression analysis was performed with adjustment for gender, race and fat free mass. Results: Significantly higher PAL (1.57 ± 0.15) were determined in girls compared to boys (PAL = 1.41 ± 0.10). Black adolescents indicated significant higher PAL (1.53 ± 0.14) compared to white adolescents (1.45 ± 0.16). On average, regardless of race or gender, the participants were more active on weekdays than weekends. The current study shows that girls spent more minutes/day in moderate to vigorous physical activity (MVPA) than the boys. The results show that 16.4% of the study sample was either overweight or obese. After adjustment for gender, ethnicity and FFM, linear regression between RMR and moderate-to-vigorous PA yielded an r2 = 0.46 (p ˂ 0.05.) Conclusion: Objectively determined PA of adolescents in South Africa indicates that only one third of adolescents are meeting the recommended 60 minutes of daily MVPA. Gender and race specific interventions are needed to increase habitual physical activity levels in adolescents. Given the fact that the studied sample did not meet recommended daily physical activity and the adverse effect of inactivity and chronic diseases of life style, urgent strategies to inculcate the culture of regular physical activity as a preventative measure of chronic diseases of life style are needed. Behaviour that is carried on into adulthood is established during adolescence. Civic health efforts should focus on encouraging adolescent involvement in regular moderate-to-vigorous PA, which will subsequently increase RMR and lower the risk of the development of non-communicable chronic diseases such as obesity. Further local research is needed to confirm the association between RMR and PA in the local population. / Thesis (MSc (Biokinetics))--North-West University, Potchefstroom Campus, 2013.

Television viewing is one of the most easily modifiable causes of obesity among children. The purpose of this study was to determine the relationship between body composition and TV viewing among adolescents attending high schools in the Tlokwe municipality area of the North West province of South Africa. A cross-sectional study design which is part of the Physical Activity and Health Longitudinal Study (PAHLS) was followed on 154 learners (58 boys and 96 girls) who were aged 14 years in the Tlokwe municipality area. All the learners underwent anthropometric measurements of height, weight, and two skinfolds (triceps and subscapular skinfolds). Percentage body fat (%BF) was calculated from the two skinfolds according to Slaughter‟s et al. (1988) equation. Children were classified into three groups (viz. normal, overweight and obese) according to BMI cut-off point suggested by Cole et al. (2000). Pearson correlation coefficients were used to determine the relationship between television viewing and body composition. The results show respectively high prevalence of overweight and obesity in girls (10.4%; 6.3%) as compared to the prevalence of 5% overweight in boys. With regard to TV viewing, the results show that 54% of the total group watch TV more than two hours a day, while only 11% watched TV less than one hour a day. The results show that the group that watches TV for more than 3 hours had high BMI (21.27kg/m²) and body mass (51.54kg). The group that watches TV for 1-2 hours had low BMI (18.36kg/m²) and body mass (44.79kg). There was a statisitcal significant relationship between BMI and body mass (p=0.001). A significant positive relationship between body mass and TV viewing (r=0.56; p=0.05) in overweight group was found, whilst in the obese group strong significant positive relationship was observed between percentage body fat and TV viewieng (r=0.94; p=0.01). It can be concluded that girls were more overweight and obese respectively as compared to the boys. Furthermore, both boys and girls had high percentages of TV viewing for more than two hours a day. In addition, the results indicated that adolescents who watched TV more than 3 hours are heavier and fatter. Therefore, it is recommended that parents and educational heads should encourage periods of daily physical activity. In addition, it is also important that parents play a more positive role in limiting the amount of hours their children spent watching television. / Thesis (MA (Biokinetics))--North-West University, Potchefstroom Campus, 2013.

During the past decades there has been an increase in longevity. These aging trends have an enormous economic impact and present challenges to policymakers, families, and health care providers to meet the needs of aging individuals. Aging is accompanied with various physiological changes that can limit the elderly’s functional status and their independency. Some of the most noticeable changes occur within the musculoskeletal system, however cardiorespiratory changes, as well as changes in the body composition limits the elderly’s aerobic capacity and therefore increases the risk for cardiovascular and hypokinetic diseases. Moderate physical activity reduces the risk, or prolong the onset of physiological changes and various diseases. Physical activity can also enhance functional fitness amongst the elderly. Functional fitness is having the physiologic capacity to perform normal everyday activities safely and independently without undue fatigue. The aim of this study was to determine the functional fitness as well as static balance and dynamic balance status of senior citizens. Secondly, to determine the association between: physical activity, aerobic endurance and functional fitness and status amongst senior citizens. Thirdly, to determine the association between physical activity status, aerobic endurance and static– and dynamic balance amongst elderly. A once off subject availability study was performed, and 58 senior citizens (32 females and 26 males) between the ages of 65 years and 96 years participated. The physical activity index was determined with the Sharkey and Gaskill Physical activity index questionnaire. Functional fitness was measured using the Rikli and Jones Fullerton’s functional fitness test protocol. The static balance and dynamic balance was tested with the one leg balance eyes closed and functional reach test respectively. Descriptive statistics were used to describe the status of the participants. Two way summary tables were used to categorize the amount of weak test results. Partial correlations were used to determine the association between physical activity, functional fitness and static and dynamic balance. The male participants’ functional fitness status compared well with USA normal ranges, however the functional fitness test scores of the female participants were even lower than the older age group (75 to 79 years) of the USA normal ranges. The results of the frequency distribution indicated that 80.77% and 68.75% of the male and female participants respectively, tested poorly in more than four of the functional fitness tests. Neither the male nor the female participants’ static balance score were adequate, although it does not indicate a fall risk. Aerobic endurance showed to have medium (r = 0.3–0.49) to high (r 0.5) partial correlation with all functional fitness tests for the total group, as well as in the female participants. In the male participants aerobic endurance only showed high correlation (r 0.5) with lower body strength and dynamic balance and agility. Dynamic balance correlated well (r 0.5) with all functional fitness tests as well as aerobic endurance and physical activity index in the female participants, and only showed a medium correlation with agility in the male participants. This study showed alarming percentages of poor test results for both male and female senior citizens and highlights the need for physical activity interventions in old age homes. The correlations between aerobic endurance, as well as dynamic balance and functional fitness tests indicates that even simple interventions such as walking programs could enhance the functional fitness of senior citizens and thereby increase their independency. / Thesis (M.A. (Biokinetics))--North-West University, Potchefstroom Campus, 2011.

During the past decades there has been an increase in longevity. These aging trends have an enormous economic impact and present challenges to policymakers, families, and health care providers to meet the needs of aging individuals. Aging is accompanied with various physiological changes that can limit the elderly’s functional status and their independency. Some of the most noticeable changes occur within the musculoskeletal system, however cardiorespiratory changes, as well as changes in the body composition limits the elderly’s aerobic capacity and therefore increases the risk for cardiovascular and hypokinetic diseases. Moderate physical activity reduces the risk, or prolong the onset of physiological changes and various diseases. Physical activity can also enhance functional fitness amongst the elderly. Functional fitness is having the physiologic capacity to perform normal everyday activities safely and independently without undue fatigue. The aim of this study was to determine the functional fitness as well as static balance and dynamic balance status of senior citizens. Secondly, to determine the association between: physical activity, aerobic endurance and functional fitness and status amongst senior citizens. Thirdly, to determine the association between physical activity status, aerobic endurance and static– and dynamic balance amongst elderly. A once off subject availability study was performed, and 58 senior citizens (32 females and 26 males) between the ages of 65 years and 96 years participated. The physical activity index was determined with the Sharkey and Gaskill Physical activity index questionnaire. Functional fitness was measured using the Rikli and Jones Fullerton’s functional fitness test protocol. The static balance and dynamic balance was tested with the one leg balance eyes closed and functional reach test respectively. Descriptive statistics were used to describe the status of the participants. Two way summary tables were used to categorize the amount of weak test results. Partial correlations were used to determine the association between physical activity, functional fitness and static and dynamic balance. The male participants’ functional fitness status compared well with USA normal ranges, however the functional fitness test scores of the female participants were even lower than the older age group (75 to 79 years) of the USA normal ranges. The results of the frequency distribution indicated that 80.77% and 68.75% of the male and female participants respectively, tested poorly in more than four of the functional fitness tests. Neither the male nor the female participants’ static balance score were adequate, although it does not indicate a fall risk. Aerobic endurance showed to have medium (r = 0.3–0.49) to high (r 0.5) partial correlation with all functional fitness tests for the total group, as well as in the female participants. In the male participants aerobic endurance only showed high correlation (r 0.5) with lower body strength and dynamic balance and agility. Dynamic balance correlated well (r 0.5) with all functional fitness tests as well as aerobic endurance and physical activity index in the female participants, and only showed a medium correlation with agility in the male participants. This study showed alarming percentages of poor test results for both male and female senior citizens and highlights the need for physical activity interventions in old age homes. The correlations between aerobic endurance, as well as dynamic balance and functional fitness tests indicates that even simple interventions such as walking programs could enhance the functional fitness of senior citizens and thereby increase their independency. / Thesis (M.A. (Biokinetics))--North-West University, Potchefstroom Campus, 2011.

Participation in leisure-time physical activity (LTPA) is vital to ensure adequate physical work capacity for the demands of daily living and job performance. Due to work demand, most top and middle (executive) managerial employees become physically inactive and experience psychological and other health problems which may lead to hypokinetic diseases and even premature death. The purpose of this study was twofold: to determine leisure-time physical activity and psychological well-being status of executive employees; and to determine the relationship between leisure-time physical activity and psychological well-being status of executive employees in selected African countries. A cross-sectional study design was carried out on a group of 156 (mean age 41.22±10.17) available executive employees from selected African countries. Participants were grouped according to age (≤35 years; 36–46 years and ≥ 46 years). Standardised questionnaires were used to collect the data. Subsequently, total scores were calculated for all variables. Out of 156 participants in the study, 42.9% occupied top level management and 57.1% middle level management positions. When data was analysed according to age groups, 31.4% and 68.6% in the less than 35 years age group were in the top and the middle level management positions respectively. In the age group 36 to 46 years, 47.2% occupied the top level management position and 52.8% occupied the middle level management position. With regard to LTPA, top level managers (71.6%) scored low LTPA compared to the middle level managers (62.9%). In addition, both the top and middle level managers reported bad emotional index (49.3%; 56.2%) and happiness index (41.8%; 37.1%) respectively. Though not significant, LTPA was positively associated with psychological well-being parameters amongst top level managers. The study concluded that both top and middle level managers exhibited low LTPA, and with no participation in high physical activity among top level managers. In addition, more middle level managers reported bad emotional stage than the top level managers, while the top level managers were less happy than the middle level managers. The study therefore recommends urgent strategic intervention programmes for leisure-time physical activity and psychological well-being. / MSc (Biokinetics), North-West University, Potchefstroom Campus, 2014

Background: South Africa is a multicultural, multi-ethnic developing country currently experiencing a unique quadruple burden of disease, of which malnutrition (both over- and under nutrition) is one of them. The increase in childhood obesity within the current South-African health setting is of serious concern, approximately 14% boys and 18% girls currently are overweight and it is estimated that this number will increase to 25% within the next decade. Healthy eating habits and increased physical activity are important components of a healthy lifestyle, and decrease the risk of overweight and obesity. It is also often the corner stone of many lifestyle modification intervention programmes aimed at preventing or decreasing overweight/obesity. Aim: This sub-study was part of a larger intervention study where a nutrition education intervention programme (NEIP) for children in the form of a musical play (based on the South African Food Based Dietary Guidelines [SAFBDG]) was developed to increase nutrition knowledge and thereby also contribute towards healthy lifestyle behaviour. The aim of this sub-study was therefore to explore and describe the attitude of a specific group of primary school children (aged 6-12 years) towards healthy eating, unhealthy eating, and physical activity before and after a NEIP as well as the standard school curriculum. Secondly, it was aimed to identify possible barriers to and motivators for healthy eating, unhealthy eating and physical activity. Methods: Children were randomly selected from the experimental group (n=143) of the main study. Children were selected into one of four focus groups per school (6 children per focus group) from which qualitative data were gathered on children’s attitude and perception towards healthy eating, unhealthy eating, and physical activity. Focus groups were defined by age and gender (boys and girls seperately, grades I-III and grades IVVI seperately), totalling a number of 96 children. A total of 75 children completed this sub-study, 21 children dropped out due to school-related problems or after school activities that clashed with the time slots during which the NEIP was implimented. Quantitative data was gathered with a socio-demographic and physical activity questionnaire, as well as a 3-point hedonic facial expression scale which was used to quantify attitude towards healthy eating, unhealhty eating and physical activity. All data (quantitative and qualitative) were collected at both baseline and end measurements. Results: The main findings of this sub-study were that the attitude of most primary school children towards healthy eating, unhealthy eating or physical activity remained unchanged after a unique NEIP. Five major themes were identified out of focus group discussions namely health awareness, healthy eating, unhealthy eating, physical activity, and consequences of unhealthy eating and sedentary behaviour. Mothers were identified as the main motivator for eating healthy and avoiding unhealthy eating. The taste and smell of food were both either identified as motivators or barriers for healthy eating and unhealthy eating. Older girls associate unhealthy eating with becoming fat while many children associate the combination of unhealthy eating and being sedentary with becoming fat. Most children have a positive attitude towards physical activity and enjoy doing it although the biggest motivator for partaking in physical activity is their parents and not themselves. Conclusion: Even though some children’s attitude did change in the desired direction after the implementation of a unique and fun NEIP, most children’s attitude towards healthy eating, unhealthy eating and physical activity remained unchanged. This might have been due to the measurement tool that was not sensitive enough to detect subtle changes. Various factors that can influence children’s attitude and perceptions towards healthy eating, unhealthy eating and physical activity both positively or negatively were identified. This study is one of only a few that explored and described the ‘true’ motivators of and barriers for children’s attitude towards healthy eating, unhealthy eating and physical activity. Results generated from this sub-study can thus make a valuable contribution to the existing literature available in this specific study field. / Thesis (MSc (Dietetics))--North-West University, Potchefstroom Campus, 2012