The low physical activity (PA) levels of children have become a national public health concern in South Africa. Moreover, the quality of Physical Education (PE) in South African schools has been compromised by challenges resulting from the subject’s reintroduction after a long absence from the school curriculum. Up to date no study has investigated the effects of a quality PE programme, within the prescriptions of the South African Curriculum and Assessment Policy Statement (CAPS), on the PA and fitness levels of twelve to thirteen years old South African children. Furthermore, no PA measuring instrument exists that has been validated specifically for South African children of this age group, with which to conduct such a study. The objectives of this study were therefore, firstly, to validate a standardised PA questionnaire for Grade 7 learners in a South African context; secondly, to evaluate the effects of an enhanced quality PE programme presented by well-trained teachers, on the PA levels, and thirdly on the physical and motor fitness of Grade 7 learners in Potchefstroom, South Africa. For the first objective, 108 schoolchildren aged twelve to thirteen years (boys, n=45; girls, n=63) from two primary schools in Potchefstroom participated in this study to validate the Children’s Leisure Activities Study Survey (CLASS) for children in a South African context. Test-retest reliability of the questionnaire was examined with an interval of 3 weeks, while validity was assessed by comparing measurements of the reported minutes in PAs from questionnaire responses with ten physical fitness parameters using the Eurofit test battery. Data analysis included Cronbach’s alpha coefficients, paired t-test and intra-class correlation coefficients (ICC), and Spearman correlation coefficients (r). The results showed substantial internal consistency and significant intra-class correlations estimates for all intensities of PA and sedentary time (ST). Non-significant differences were found in the means of test and retest measurements. Aerobic fitness was significantly correlated with all intensities of PA and ST, and the results of several of the other fitness tests had significant associations with vigorous PA. For the fulfillment of the second and the third objectives, 110 Grade 7 learners (experimental school, n = 40; control schools, n = 70) were studied. The twelve-week PE intervention programme was presented according to the prescriptions of the CAPS which allocates one hour per week to PE, but included 5 quality-enhancing components namely well-trained teachers, homework activities, a reward system, improvised apparatus and the monitoring of activity intensity. Data was collected by means of the validated CLASS questionnaire, anthropometric measurements as well as physical and motor fitness tests, by means of the Eurofit test battery. Data analysis included Kruskal-Wallis and Wilcoxon signed-rank tests, a series of analyses of covariance (ANCOVA), Tukey’s post hoc analysis, and interpreting effect sizes for practical significance. The results showed practically and statistically significant increases in moderate PA, vigorous PA, and total PA as well as decreases in sedentary behaviours. Furthermore, the learners’ data on physical and motor fitness levels showed statistically significant improvements among most of the experimental groups with regard to six of the ten fitness parameters. Based on these results, it can be concluded that the enhanced quality PE programme is effective in improving the PA, physical and motor fitness levels of South African primary school children. Therefore it is recommended that PE programmes in South Africa include the quality-enhancing components used in this intervention programme. Moreover, the modified CLASS questionnaire is a valid and reliable measure of PA among South African Grade 7 schoolchildren. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015

The low physical activity (PA) levels of children have become a national public health concern in South Africa. Moreover, the quality of Physical Education (PE) in South African schools has been compromised by challenges resulting from the subject’s reintroduction after a long absence from the school curriculum. Up to date no study has investigated the effects of a quality PE programme, within the prescriptions of the South African Curriculum and Assessment Policy Statement (CAPS), on the PA and fitness levels of twelve to thirteen years old South African children. Furthermore, no PA measuring instrument exists that has been validated specifically for South African children of this age group, with which to conduct such a study. The objectives of this study were therefore, firstly, to validate a standardised PA questionnaire for Grade 7 learners in a South African context; secondly, to evaluate the effects of an enhanced quality PE programme presented by well-trained teachers, on the PA levels, and thirdly on the physical and motor fitness of Grade 7 learners in Potchefstroom, South Africa. For the first objective, 108 schoolchildren aged twelve to thirteen years (boys, n=45; girls, n=63) from two primary schools in Potchefstroom participated in this study to validate the Children’s Leisure Activities Study Survey (CLASS) for children in a South African context. Test-retest reliability of the questionnaire was examined with an interval of 3 weeks, while validity was assessed by comparing measurements of the reported minutes in PAs from questionnaire responses with ten physical fitness parameters using the Eurofit test battery. Data analysis included Cronbach’s alpha coefficients, paired t-test and intra-class correlation coefficients (ICC), and Spearman correlation coefficients (r). The results showed substantial internal consistency and significant intra-class correlations estimates for all intensities of PA and sedentary time (ST). Non-significant differences were found in the means of test and retest measurements. Aerobic fitness was significantly correlated with all intensities of PA and ST, and the results of several of the other fitness tests had significant associations with vigorous PA. For the fulfillment of the second and the third objectives, 110 Grade 7 learners (experimental school, n = 40; control schools, n = 70) were studied. The twelve-week PE intervention programme was presented according to the prescriptions of the CAPS which allocates one hour per week to PE, but included 5 quality-enhancing components namely well-trained teachers, homework activities, a reward system, improvised apparatus and the monitoring of activity intensity. Data was collected by means of the validated CLASS questionnaire, anthropometric measurements as well as physical and motor fitness tests, by means of the Eurofit test battery. Data analysis included Kruskal-Wallis and Wilcoxon signed-rank tests, a series of analyses of covariance (ANCOVA), Tukey’s post hoc analysis, and interpreting effect sizes for practical significance. The results showed practically and statistically significant increases in moderate PA, vigorous PA, and total PA as well as decreases in sedentary behaviours. Furthermore, the learners’ data on physical and motor fitness levels showed statistically significant improvements among most of the experimental groups with regard to six of the ten fitness parameters. Based on these results, it can be concluded that the enhanced quality PE programme is effective in improving the PA, physical and motor fitness levels of South African primary school children. Therefore it is recommended that PE programmes in South Africa include the quality-enhancing components used in this intervention programme. Moreover, the modified CLASS questionnaire is a valid and reliable measure of PA among South African Grade 7 schoolchildren. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015

During the growth spurt (GS) which forms part of the mid-adolescence period of boys (13-17 years), considerable changes take place in the body composition of boys. It is therefore an unstable period where imbalances in body proportions (muscle mass, fat mass, neurological development) occur, that might have an effect on sport performance. It is also accompanied by changes in physical and motor fitness. The study firstly aimed to determine anthropometric growth changes in stature, arm span, mass, sitting height and sitting height ratio during mid-adolescence over a period of three years. The study secondly aimed to investigate the developmental changes in physical fitness (muscle strength, aerobic endurance) and motor fitness abilities (speed, agility, hand- eye coordination, explosive power) during the mid-adolescence phase of boys and finally to investigate possible relationships between anthropometric and physical and motor fitness abilities over the course of three years. A convenience sample consisting of all the grade 8 learners (n=182) of a quintile 5 high school in Potchefstroom in the North-West province of South Africa was selected to participate in a longitudinal growth research project over a three year period. Only the boys, with a mean age of 13.58 years in grade 8, of whom 95.4 % were white, 2.3% black and 2.3% colored boys, were part of the study. In 2010, 87 boys had complete measurements, while the final group in 2012 with completed follow-up measurements, were 73 boys. The physical and motor fitness components were measured according to the Australian Sport Search Program consisting of 10 tests (4 anthropometrical tests, 5 motor fitness tests, 1 physical fitness test). The cricket ball throwing test was added as an additional test. The anthropometrical measurements were made using the protocol of ISAK, while sitting height was measured according to the Canadian Sports for Life protocol. Sitting height ratio was calculated according to the formula (sitting height/stature x 100). The data was processed by “Statistica for Windows” Statsoft-computer program package. Descriptive statistics that included means (M), standard deviations (SD) and minimum and maximum values were used. A repeated measures over time analysis of variance (ANOVA) with a Bonferonni adjustment was done to analyze the differences over a period of 3 years within the group for all variables, where p<0.05 indicates a statistically significant difference. A partial correlation analysis was used to determine correlations between variables. Practical significance of correlations was determined according to Cohen’s d-value (0.1=small, 0.3=medium, 0.5=large). The results showed that during mid-adolescence in the period 13.58-14.58 years, boys grow considerably in stature, body mass, arm span and sitting height with accompanying improvement in motor and physical fitness abilities while sitting height ratio showed the greatest increase from 14.58-15.57 years. Stature, mass and arm span showed a parallel development up to 15 years after which further development leveled off, while mass increase showed no leveling off. Speed, agility, coordination and isometric-dynamic shoulder strength (basketball throw) also showed the biggest and significant improvement from 13.58-15.57 years, while explosive leg power and upper body arm and shoulder strength (vertical jump, cricket ball throw) showed the biggest and significant improvements during the period from 14.58 to 15.57 years. Significant correlations up to r=0.74; p<0.05, were found between changes in physical and motor fitness abilities and anthropometric variables, although the correlations become smaller over the 3-year period. Hand-eye coordination showed no correlation with any anthropometrical changes, while upper body strength correlated with all the anthropometrical measurements except sitting height ratio throughout the three years. It was concluded that the most accelerated growth and development took place from 13.58- 15.57 years in boys when they are in their first high school year and which falls within the mid-adolescent period (13-15 years). Furthermore, clear relationships were found between anthropometric, motor- and physical fitness variables. This knowledge of the rate of growth and motor fitness development and the relationships between these variables during the midadolescence period can provide a better understanding of changes that boys underwent during the mid-adolescent period, and can help monitoring the level of physical maturity in adolescents in order to develop training, competition and rehabilitation programs according to their developmental and not their chronological age. This cannot only prevent injuries, but also prevent early burnout in sport. / MA (Sport Science), North-West University, Potchefstroom Campus, 2014

During the growth spurt (GS) which forms part of the mid-adolescence period of boys (13-17 years), considerable changes take place in the body composition of boys. It is therefore an unstable period where imbalances in body proportions (muscle mass, fat mass, neurological development) occur, that might have an effect on sport performance. It is also accompanied by changes in physical and motor fitness. The study firstly aimed to determine anthropometric growth changes in stature, arm span, mass, sitting height and sitting height ratio during mid-adolescence over a period of three years. The study secondly aimed to investigate the developmental changes in physical fitness (muscle strength, aerobic endurance) and motor fitness abilities (speed, agility, hand- eye coordination, explosive power) during the mid-adolescence phase of boys and finally to investigate possible relationships between anthropometric and physical and motor fitness abilities over the course of three years. A convenience sample consisting of all the grade 8 learners (n=182) of a quintile 5 high school in Potchefstroom in the North-West province of South Africa was selected to participate in a longitudinal growth research project over a three year period. Only the boys, with a mean age of 13.58 years in grade 8, of whom 95.4 % were white, 2.3% black and 2.3% colored boys, were part of the study. In 2010, 87 boys had complete measurements, while the final group in 2012 with completed follow-up measurements, were 73 boys. The physical and motor fitness components were measured according to the Australian Sport Search Program consisting of 10 tests (4 anthropometrical tests, 5 motor fitness tests, 1 physical fitness test). The cricket ball throwing test was added as an additional test. The anthropometrical measurements were made using the protocol of ISAK, while sitting height was measured according to the Canadian Sports for Life protocol. Sitting height ratio was calculated according to the formula (sitting height/stature x 100). The data was processed by “Statistica for Windows” Statsoft-computer program package. Descriptive statistics that included means (M), standard deviations (SD) and minimum and maximum values were used. A repeated measures over time analysis of variance (ANOVA) with a Bonferonni adjustment was done to analyze the differences over a period of 3 years within the group for all variables, where p<0.05 indicates a statistically significant difference. A partial correlation analysis was used to determine correlations between variables. Practical significance of correlations was determined according to Cohen’s d-value (0.1=small, 0.3=medium, 0.5=large). The results showed that during mid-adolescence in the period 13.58-14.58 years, boys grow considerably in stature, body mass, arm span and sitting height with accompanying improvement in motor and physical fitness abilities while sitting height ratio showed the greatest increase from 14.58-15.57 years. Stature, mass and arm span showed a parallel development up to 15 years after which further development leveled off, while mass increase showed no leveling off. Speed, agility, coordination and isometric-dynamic shoulder strength (basketball throw) also showed the biggest and significant improvement from 13.58-15.57 years, while explosive leg power and upper body arm and shoulder strength (vertical jump, cricket ball throw) showed the biggest and significant improvements during the period from 14.58 to 15.57 years. Significant correlations up to r=0.74; p<0.05, were found between changes in physical and motor fitness abilities and anthropometric variables, although the correlations become smaller over the 3-year period. Hand-eye coordination showed no correlation with any anthropometrical changes, while upper body strength correlated with all the anthropometrical measurements except sitting height ratio throughout the three years. It was concluded that the most accelerated growth and development took place from 13.58- 15.57 years in boys when they are in their first high school year and which falls within the mid-adolescent period (13-15 years). Furthermore, clear relationships were found between anthropometric, motor- and physical fitness variables. This knowledge of the rate of growth and motor fitness development and the relationships between these variables during the midadolescence period can provide a better understanding of changes that boys underwent during the mid-adolescent period, and can help monitoring the level of physical maturity in adolescents in order to develop training, competition and rehabilitation programs according to their developmental and not their chronological age. This cannot only prevent injuries, but also prevent early burnout in sport. / MA (Sport Science), North-West University, Potchefstroom Campus, 2014

In the past various studies were undertaken to establish the fact that there are physical differences between the various races. As there is not much known about the motor ability of especially the Coloured and Indian schoolboys, this study was undertaken to ascertain whether there is any difference in motor ability between the White, Coloured and Indian boys in this age group. After a careful study of the known facts and the various test batteries for the measurement of motor ability, a test battery, consisting of six items was selected. The six items were the 75 yard dash, 220 yards, pull ups on the horizontal bar, shotput, standing long jump and cricket ball throw for distance. The length and weight of the body were also taken. This test battery includes all the components of motor ability and meets the requirements of a good test. The six item test battery was administered to 120 Indian, 140 Coloured and 90 White schoolboys. The selected data was statistically compiled and the achievement of 12 and 13 year old Whites, 12 and 13 year old Indians and 12 and 13 year old Coloureds were compared. Thereafter the results of the 12 and 13 year old Whites were compared with that of the Indian and Coloured boys and the achievement of the Indian boys was compared with that of the Coloured boys. The following results were established: 1. No significant differences were found between the 12 and 13 year old Whites except in the shotput where there was a highly significant difference and a significant difference in the 75 yard dash and pull ups in favour of the 13 year olds. The other two races showed highly significant differences in favour of the 13 year olds in all the test items. 2. The Whites surpassed the other two races highly significantly in all the test items. The Coloureds, although highly significantly shorter and significantly lighter than the Indian boys, surpassed the latter highly significantly in the cricket ball throw for distance, the standing long jump; significantly in the 220 yards and insignificantly in the shotput, 75 yard dash and pull ups, compiled according to McCloy's formulae. 3. A comparison between the Indian Moslem and Hindu boys showed that the Moslem boys surpassed the Hindus highly significantly in all the items except in the shotput. There is no significant difference between the 12 and 13 year old Hindu boys. 4. The physical differences between the three racial groups are inherited and cannot be attributed to environmental factors only. / Thesis (MEd)--PU vir CHO

In the past various studies were undertaken to establish the fact that there are physical differences between the various races. As there is not much known about the motor ability of especially the Coloured and Indian schoolboys, this study was undertaken to ascertain whether there is any difference in motor ability between the White, Coloured and Indian boys in this age group. After a careful study of the known facts and the various test batteries for the measurement of motor ability, a test battery, consisting of six items was selected. The six items were the 75 yard dash, 220 yards, pull ups on the horizontal bar, shotput, standing long jump and cricket ball throw for distance. The length and weight of the body were also taken. This test battery includes all the components of motor ability and meets the requirements of a good test. The six item test battery was administered to 120 Indian, 140 Coloured and 90 White schoolboys. The selected data was statistically compiled and the achievement of 12 and 13 year old Whites, 12 and 13 year old Indians and 12 and 13 year old Coloureds were compared. Thereafter the results of the 12 and 13 year old Whites were compared with that of the Indian and Coloured boys and the achievement of the Indian boys was compared with that of the Coloured boys. The following results were established: 1. No significant differences were found between the 12 and 13 year old Whites except in the shotput where there was a highly significant difference and a significant difference in the 75 yard dash and pull ups in favour of the 13 year olds. The other two races showed highly significant differences in favour of the 13 year olds in all the test items. 2. The Whites surpassed the other two races highly significantly in all the test items. The Coloureds, although highly significantly shorter and significantly lighter than the Indian boys, surpassed the latter highly significantly in the cricket ball throw for distance, the standing long jump; significantly in the 220 yards and insignificantly in the shotput, 75 yard dash and pull ups, compiled according to McCloy's formulae. 3. A comparison between the Indian Moslem and Hindu boys showed that the Moslem boys surpassed the Hindus highly significantly in all the items except in the shotput. There is no significant difference between the 12 and 13 year old Hindu boys. 4. The physical differences between the three racial groups are inherited and cannot be attributed to environmental factors only. / Thesis (MEd)--PU vir CHO

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.

Obesity and physical inactivity (PI) are major health problems world-wide, and leading contributors to the high incidence of overweight, cardiovascular and metabolic diseases in children both globally and in South Africa in particular. Despite the importance of physical activity (PA), health-related physical fitness (HRPF) and body composition to health, very few studies have investigated the longitudinal relationship between these variables in children. Three articles based on this research were written in which a total of 283 adolescent learners (111 boys and 172 girls) with a mean age of 14.90±0.72 years from the Physical Activity and Health Longitudinal Study (PAHLS) participated. The students’ physical characteristics were measured using the protocol of the International Society for the Advancement of Kinanthropometry (ISAK); the EUROFIT test protocol and International Physical Activity Questionnaire (IPAQ) were used to assess the children’s HRPF and PA levels, respectively. In the first article, the results showed that girls had a slightly higher significant BMI (21.43±4.37 kg/m²) than the boys (20.01±3.71kg/m²) (p=0.002), and were substantially more overweight (32.4%) and fatter (%body fat=26.01±8.51) than the boys (17.1%)). A total of 85 (30%), 78 (27.5%) and 88 (31.1%) of the students had low, moderate and high PA involvement. It was concluded that girls were more overweight and less active than boys. The second article examined the relationships between body composition, health-related fitness and PA. Inverse relationships were found between BMI and the health-related fitness items of SBJ and BAH. Furthermore, BMI negatively associated with SAR and endurance performance, especially in girls. Percentage body fat was negatively related to SBJ, BAH, SAR and endurance performance. The aim of the third article was to evaluate the longitudinal development of HRPF, anthropometry and body composition status among the children. Regression coefficients showed that changes in BMI were inversely associated with those in health-related physical fitness. The changes in %BF were negatively associated with SBJ, BAH and aerobic capacity (VO2max) in the boys and girls. The results also yielded a low significantly positive association between changes in WHtR and SBJ in both genders, while low inverse associations were found between WHtR and BAH in girls, and VO2max in both genders. It is concluded that the incidence of overweight and PI was especially high in girls and excessive fatness negatively affected the girls’ fitness performances. Changes in BMI, % body fat and WHtR were negatively related with the children’s strength and running performances, especially among the girls in which the relative increase in overweight negatively affected their endurance running and static strength performances. In view of the health implications of the findings, it is necessary to create an enabling environment and opportunities to promote physically active lifestyles and develop life-long positive attitudes towards PA among students. Community-based strategies targeted at facilitating sustainable PA intervention programmes in schools are recommended. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014

Obesity and physical inactivity (PI) are major health problems world-wide, and leading contributors to the high incidence of overweight, cardiovascular and metabolic diseases in children both globally and in South Africa in particular. Despite the importance of physical activity (PA), health-related physical fitness (HRPF) and body composition to health, very few studies have investigated the longitudinal relationship between these variables in children. Three articles based on this research were written in which a total of 283 adolescent learners (111 boys and 172 girls) with a mean age of 14.90±0.72 years from the Physical Activity and Health Longitudinal Study (PAHLS) participated. The students’ physical characteristics were measured using the protocol of the International Society for the Advancement of Kinanthropometry (ISAK); the EUROFIT test protocol and International Physical Activity Questionnaire (IPAQ) were used to assess the children’s HRPF and PA levels, respectively. In the first article, the results showed that girls had a slightly higher significant BMI (21.43±4.37 kg/m²) than the boys (20.01±3.71kg/m²) (p=0.002), and were substantially more overweight (32.4%) and fatter (%body fat=26.01±8.51) than the boys (17.1%)). A total of 85 (30%), 78 (27.5%) and 88 (31.1%) of the students had low, moderate and high PA involvement. It was concluded that girls were more overweight and less active than boys. The second article examined the relationships between body composition, health-related fitness and PA. Inverse relationships were found between BMI and the health-related fitness items of SBJ and BAH. Furthermore, BMI negatively associated with SAR and endurance performance, especially in girls. Percentage body fat was negatively related to SBJ, BAH, SAR and endurance performance. The aim of the third article was to evaluate the longitudinal development of HRPF, anthropometry and body composition status among the children. Regression coefficients showed that changes in BMI were inversely associated with those in health-related physical fitness. The changes in %BF were negatively associated with SBJ, BAH and aerobic capacity (VO2max) in the boys and girls. The results also yielded a low significantly positive association between changes in WHtR and SBJ in both genders, while low inverse associations were found between WHtR and BAH in girls, and VO2max in both genders. It is concluded that the incidence of overweight and PI was especially high in girls and excessive fatness negatively affected the girls’ fitness performances. Changes in BMI, % body fat and WHtR were negatively related with the children’s strength and running performances, especially among the girls in which the relative increase in overweight negatively affected their endurance running and static strength performances. In view of the health implications of the findings, it is necessary to create an enabling environment and opportunities to promote physically active lifestyles and develop life-long positive attitudes towards PA among students. Community-based strategies targeted at facilitating sustainable PA intervention programmes in schools are recommended. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014