Please read the abstract in the dissertation. / Dissertarion (MSc)--University of Pretoria, 1978 / gm2013 / Mathematics and Applied Mathematics / unrestricted

The dose-response relationship between physical activity (PA), disease and mortality has primarily been obtained from self-report questionnaires in Western populations. A major limitation of self-reported PA is the likelihood of measurement error and these recordings cannot account for all 24-h activities, thus negating the influence of sedentary time and daily light intensity activity. Modern-day studies using objective measures of PA are highly controversial in the description of PA, as well as reliable wear time of these objective devices to accurately assess PA behaviour. The aim of the research presented in this thesis was to ascertain the associations between seven-day objectively measured PA (expressed as time spent in four different metabolic equivalent of task (MET) categories), cardiovascular disease risk factors (24-h ambulatory blood pressure and central obesity), chronic stress (General Health Questionnaire total score and serum cortisol) and DNA damage (leukocyte telomere length) in a cohort of African and Caucasian school teachers recruited from the Dr Kenneth Kaunda Education District in the North West Province of South Africa. All parameters were objectively measured (the GHQ was only added for thoroughness on measures of cognitive perceived stress) in the study population. The Africans (n=96) were younger than the Caucasians (n=107) (48.33 versus 51.06 years, p=0.024), but presented with slightly higher waist circumferences, significantly higher 24-h ambulatory systolic blood pressure (SBP, p≤0.000), diastolic blood pressure (DBP, p≤0.000) and mean arterial pressure (MAP, p≤0.000); significantly higher perceived stress scores (GHQ total scores, p=0.001) and significantly shorter telomeres (p≤0.000). The hypertensive participants in the total group (Africans and Caucasians combined) recorded 2.2 hours (12.4%) more daily awake sedentary time than the normotensive participants (p=0.004) and sedentary time was also a slightly better predictor of hypertension than moderate and vigorous activity time (Odds ratio=1.00, p=0.006). Irrespective of race and sex, 24-h SBP and DBP measurements were respectively associated with daily awake sedentary time (ß=0.17, p=0.018 and ß=0.18, p=0.020), light activity time (ß=-0.15, p=0.043 and ß=-0.16, p=0.041), waist circumference (ß=0.45, p≤0.000 and ß=0.33, p≤0.000) and log serum gamma glutamyl transferase (γ-GT, alcohol use) (ß=0.18, p=0.018 and ß=0.24, p=0.004). An older age (ß=-0.28, p≤0.000), higher alcohol consumption (ß=-0.21, p=0.003) and increased central obesity (ß=-0.17, p=0.017) were associated with shorter telomeres. Attenuated cortisol levels (ß=-0.12, p=0.068) showed a tendency towards associations with longer telomeres that may indicate possible cortisol down regulation to protect against DNA damage. Time spent in the different MET-categories showed no direct associations with either cortisol or telomere length. However, a sensitivity analysis indicated that daily light intensity activity time was significantly correlated with lower waist circumference (r=-0.21, p=0.004); a parameter associated with both cortisol (ß=-0.22, p=0.003) and telomere length (ß=-0.17, p=0.017). The thorough recording of PA during the true awake time of 24-h cycles over a period of seven days ensured that the beneficial effect of light intensity activities, as well as the detrimental effect of sedentary time, was highlighted by this study. The average awake time of all ethnic and sex groups were around 17 hours per day, which was more than most previous studies using objective measures of PA. The exclusion of participants who did not comply through wearing the Actiheart for a full seven days (n=143, 40%) did, however, have a negative impact on sample size that may have affected the statistical power for uncovering some significant associations and the high participant burden of the Actiheart device became clear. Therefore, the researchers used the data of the full seven-day recordings to also determine the minimum number of consecutive days the Actiheart device could be worn to accurately estimate energy expenditure and PA. The two-day combination of Wednesday-to-Thursday did not differ from the weekly average TEE, as well as for all MET-categories in all ethnic and sex groups. This two-day combination is practically convenient and would lessen participant burden. Future researchers are urged to test this combination in other populations to standardize Actiheart wear time. It can be concluded from the findings in this study that less daily awake sedentary time, more light intensity activity time, as well as lower alcohol consumption favour improved health as it is beneficial to 24-h ambulatory blood pressure and helps to maintain a healthy waist circumference, which ultimately influence telomere shortening. Furthermore, the two-day combination of Wednesday-to-Thursday seems to be sufficient to accurately estimate weekly energy expenditure and habitual PA with the Actiheart apparatus. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015

The dose-response relationship between physical activity (PA), disease and mortality has primarily been obtained from self-report questionnaires in Western populations. A major limitation of self-reported PA is the likelihood of measurement error and these recordings cannot account for all 24-h activities, thus negating the influence of sedentary time and daily light intensity activity. Modern-day studies using objective measures of PA are highly controversial in the description of PA, as well as reliable wear time of these objective devices to accurately assess PA behaviour. The aim of the research presented in this thesis was to ascertain the associations between seven-day objectively measured PA (expressed as time spent in four different metabolic equivalent of task (MET) categories), cardiovascular disease risk factors (24-h ambulatory blood pressure and central obesity), chronic stress (General Health Questionnaire total score and serum cortisol) and DNA damage (leukocyte telomere length) in a cohort of African and Caucasian school teachers recruited from the Dr Kenneth Kaunda Education District in the North West Province of South Africa. All parameters were objectively measured (the GHQ was only added for thoroughness on measures of cognitive perceived stress) in the study population. The Africans (n=96) were younger than the Caucasians (n=107) (48.33 versus 51.06 years, p=0.024), but presented with slightly higher waist circumferences, significantly higher 24-h ambulatory systolic blood pressure (SBP, p≤0.000), diastolic blood pressure (DBP, p≤0.000) and mean arterial pressure (MAP, p≤0.000); significantly higher perceived stress scores (GHQ total scores, p=0.001) and significantly shorter telomeres (p≤0.000). The hypertensive participants in the total group (Africans and Caucasians combined) recorded 2.2 hours (12.4%) more daily awake sedentary time than the normotensive participants (p=0.004) and sedentary time was also a slightly better predictor of hypertension than moderate and vigorous activity time (Odds ratio=1.00, p=0.006). Irrespective of race and sex, 24-h SBP and DBP measurements were respectively associated with daily awake sedentary time (ß=0.17, p=0.018 and ß=0.18, p=0.020), light activity time (ß=-0.15, p=0.043 and ß=-0.16, p=0.041), waist circumference (ß=0.45, p≤0.000 and ß=0.33, p≤0.000) and log serum gamma glutamyl transferase (γ-GT, alcohol use) (ß=0.18, p=0.018 and ß=0.24, p=0.004). An older age (ß=-0.28, p≤0.000), higher alcohol consumption (ß=-0.21, p=0.003) and increased central obesity (ß=-0.17, p=0.017) were associated with shorter telomeres. Attenuated cortisol levels (ß=-0.12, p=0.068) showed a tendency towards associations with longer telomeres that may indicate possible cortisol down regulation to protect against DNA damage. Time spent in the different MET-categories showed no direct associations with either cortisol or telomere length. However, a sensitivity analysis indicated that daily light intensity activity time was significantly correlated with lower waist circumference (r=-0.21, p=0.004); a parameter associated with both cortisol (ß=-0.22, p=0.003) and telomere length (ß=-0.17, p=0.017). The thorough recording of PA during the true awake time of 24-h cycles over a period of seven days ensured that the beneficial effect of light intensity activities, as well as the detrimental effect of sedentary time, was highlighted by this study. The average awake time of all ethnic and sex groups were around 17 hours per day, which was more than most previous studies using objective measures of PA. The exclusion of participants who did not comply through wearing the Actiheart for a full seven days (n=143, 40%) did, however, have a negative impact on sample size that may have affected the statistical power for uncovering some significant associations and the high participant burden of the Actiheart device became clear. Therefore, the researchers used the data of the full seven-day recordings to also determine the minimum number of consecutive days the Actiheart device could be worn to accurately estimate energy expenditure and PA. The two-day combination of Wednesday-to-Thursday did not differ from the weekly average TEE, as well as for all MET-categories in all ethnic and sex groups. This two-day combination is practically convenient and would lessen participant burden. Future researchers are urged to test this combination in other populations to standardize Actiheart wear time. It can be concluded from the findings in this study that less daily awake sedentary time, more light intensity activity time, as well as lower alcohol consumption favour improved health as it is beneficial to 24-h ambulatory blood pressure and helps to maintain a healthy waist circumference, which ultimately influence telomere shortening. Furthermore, the two-day combination of Wednesday-to-Thursday seems to be sufficient to accurately estimate weekly energy expenditure and habitual PA with the Actiheart apparatus. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015

Fundamentele bewegingsvaardighede is die onderbou of basis waarop al die vereiste vaardighede en aktiwiteite in die kurrikulum vir Senior Fase Liggaamlike Opvoeding van die Kurrikulum en Assesseringsbeleidsverklaring (KABV), gebou is. Dit word verder in die literatuur beklemtoon dat die kwalitiet waarmee leerders „n fundamentele bewegingsvaardigheid uitvoer, net so belangrik is soos die kwantitatiewe uitkoms van die uitvoering. Liggaamlike Opvoedingonderwysers behoort dus bewus te wees van beide die kwalitatiewe en kwantitatiewe vlakke van leerders se fundamentele bewegingsvaardighede in die lig van die vereiste ontwikkeling en inoefening van gespesialiseerde bewegings- en sportvaardighede in die Liggaamlike Opvoedingprogram. Fundamentele bewegingsvaardighede speel verder „n integrale rol in „n leerder se algehele motoriese behendigheid. Die Liggaamlike Opvoeding-onderwyser moet voorts bewus wees van geslags- en etniese verskille in fundamentele bewegingsvaardighede en motoriese behendigheid ten einde effektief in die Liggaamlike Opvoedingprogram te differensieer en by verskillende leerders se vermoëns aan te pas. Verder, aangesien dit die primêre doelstelling van Liggaamlike Opvoeding in die KABV is om leerders te bemagtig om fisiek aktief te wees, is die verwantskap tussen fundamentele bewegingsvaardighede, motoriese behendigheid en fisieke aktiwiteitsvlakke nog „n aspek wat van belang is vir die Liggaamlike Opvoeding-onderwyser in die samestelling van die Liggaamlike Opvoedingprogram. Laastens toon navorsing „n verwantskap tussen motoriese behendigheid en akademiese prestasie. Die doel van hierdie studie was eerstens om die kwantitatiewe en kwalitatiewe stand van fundamentele bewegingsvaardighede by Senior Fase leerders in die Potchefstroom-omgewing te bepaal. Die tweede doelstelling was om die verskille tussen geslagte en etniese groepe ten opsigte van motoriese behendigheid te bepaal. Die derde doelstelling was om die verband tussen motoriese behendigheid en fisieke aktiwiteit te bepaal, en laastens om die verband tussen motoriese behendigheid en akademiese prestasie te bepaal. ʼn Totaal van 239 Senior Fase leerders (98 seuns en 141 dogters), tussen die ouderdomme 13 en 14 jaar het aan die studie deelgeneem. Kwantitatiewe metodologie, met „n eenmalige dwarssnit-ontwerp, is vir die doeleindes van die studie gebruik. Die proefpersone se fundamentele bewegingsvaardighede en motoriese behendigheid is bepaal met behulp van die verkorte weergawe van die Bruininks-Oseretsky Test of Motor Proficiency 2 (BOT-2) (Bruininks & Bruininks, 2005), „n kwantitatiewe toetsbattery wat bestaan uit vier komponente, naamlik fynmotoriese kontrole, manipulasie koördinasie, liggaamskoördinasie en krag-en-ratsheid. Vir die kwalitatiewe bewegingsanalise is van die Fundamentele Bewegingspatroonassesseringsinstrument (FMPAI) (Gallahue & Donnelly, 2003) gebruik gemaak. Vir die meting van fisieke aktiwiteitsvlakke is gebruik gemaak van die gestandaardiseerde International Physical Activity Questionnaire (IPAQ) (Sjöström, 2005). Hierdie vraelys vra die deelnemer om fisieke aktiwiteite van die laaste sewe dae, en ook van ‟n normale week oor die algemeen, gemeet in totale METS (metabolic equivalent – intensiteit van oefening), te rapporteer. Die leerders se akademiese prestasie is gemeet deur gebruik te maak van die gemiddelde akademiese punt (gemiddeld van al die vakke – Afrikaans, Engels, Wiskunde, Lewensoriëring, Geskiedenis, Geografie, Natuur-Wetenskap, Tegnologie, Ekonomiese en Bestuurswetenskappe en Skeppende Kunste), op die leerder se rapport aan die einde van die jaar, asook die gemiddelde punte vir die twee vakke Engels en Wiskunde, soos op die rapport aan die einde van die jaar aangedui. Beskrywende statistiek is gebruik om gemiddeldes ( x ), minimum- en maksimumwaardes, en standaardafwykings (sa) met behulp van die Statistica vir Windows rekenaarprogram (StatSoft, 2012) te bereken. Verbande tussen die kwantitatiewe en kwalitatiewe resultate, tussen die motoriese behendigheidtoetse en die fisieke aktiwiteitsvlakke, asook tussen motoriese behendigheidstoetse en akademiese prestasie is ontleed met behulp van Spearman korrelasiekoëffisiënte. Om die praktiese betekenisvolheid van die verbande te bepaal is die korrelasiekoëffisiënt as effekgrootte (EG) gebruik. Ten einde die betekenisvolheid van geslagsen etniese verskille te bepaal, is die data verder geanaliseer deur gebruik te maak van onafhanklike t-toetse (p<0.05) en vir die doel van die interpretasie van praktiese betekenisvolheid van die verskille is effekgroottes (EG) bereken. Uit die resultate van die studie blyk dit dat daar in die kwantitatiewe evaluasie, veral by die wisselspronge, lynloop en eenbeenstand, agterstande by 20 tot 35% van die leerders was. Met betrekking tot die kwalitatiewe uitvoering van die vaardighede was die eenbeenstand by 22.6 tot 24.5% van die leerders nog nie in die volwasse stadium van bemeestering van fundamentele bewegingsvaardighede nie. Die kwantitatiewe en kwalitatiewe tellings het verder by die bonsen- vang- en die dribbel-van-die-bal toetse nie gekorreleer nie, wat daarop dui dat leerders soms kwantitatief, maar nie noodwendig kwalitatief, aan die norme voldoen het nie. Met betrekking tot verskille tussen geslagte en etniese groepe, toon die resultate dat die meisies oor die algemeen beter as die seuns gevaar het, en die Wit leerders beter gevaar het as die Swart leerders in die fynmotoriese koördinasietoetse. Met betrekking tot liggaamskoördinasie het die Wit leerders betekenisvol beter as die Swart leerders in die wisselsprongtoets gevaar. Betekenisvolle verskille is verder met betrekking tot die krag- en ratsheidkomponent gevind, waar die Wit leerders beter as die Swart leerders in die eenbeenspring-item gevaar het, terwyl onderskeidelik seuns en Wit groepe beter resultate as die meisies en die Swart groepe in die opsit- en opstoottoetse getoon het, asook met betrekking tot die totale motoriese behendigheidstelling (totale BOT-2 telling). Wat die fisieke aktiwiteitsvlakke van die proefpersone betref, toon die totale groep ʼn gemiddelde waarde van 489.68 METS per week, wat as matig-aktief geklassifiseer kon word, terwyl die seuns as hoog-aktief en die meisies as matig-aktief beskou kan word. Daar is ook statisties betekenisvolle korrelasies tussen die fisieke aktiwiteitsvlakke en verskeie motoriese vaardighede gevind, sowel as die totale BOT-2 telling by die totale groep en die seuns en meisies afsonderlik. Die motoriese sub-item waar die sterkste korrelasie met fisieke aktiwiteitvlakke in die totale groep asook by seuns en meisies afsonderlik gevind is, was die liggaamskoördinasie-item van die wisselspronge. Laastens toon die resultate met betrekking tot die verband tussen motoriese behendigheid en akademiese prestasie, betekenisvolle korrelasies tussen die verskillende groepe (seuns, meisies en totale groep) se Engelse, Wiskunde en jaargemiddeld en verskeie sub-items van al die komponente van die BOT-2, naamlik fyn-motoriese kontrole, manipulasie koördinasie, liggaamskoördinasie, krag en ratsheid, asook die totale motoriese behendigheidtelling, alhoewel hoofsaaklik met klein praktiese effekte. Die sterkste korrelasie is by al die groepe tussen die jaargemiddeld, asook die Engels en Wiskunde in ‟n mindere mate, met krag en ratsheid, gevind. Die totale motoriese behendigheidstelling het verder betekenisvol gekorreleer met die jaargemiddeld by al die groepe, met praktiese betekenisvolheid van medium effek. Die resultate van hierdie studie beklemtoon die noodsaaklikheid van die bewustheid van en assessering van die kwantitatiewe en kwalitatiewe stand van leerders se fundamentele bewegingsvaardighede deur die Liggaamlike Opvoeding-onderwyser. Die ontwikkeling en instandhouding van fundamentele bewegingsvaardighede behoort dus in die kurrikulum vir Senior Fase Liggaamlike Opvoeding ingesluit te word, ook met die oog op optimale motoriese behendigheidsontwikkeling. Die Liggaamlike Opvoeding-onderwyser behoort verder die Liggaamlike Opvoedingprogram aan te pas by die motoriese behendigheidsvlakke van die verskillende geslagte en etniese groepe in die klas, met spesifieke aandag aan die liggaamskoördinasievaardighede van Swart meisies en Swart seuns, asook krag- en ratsheidvaardighede by meisies en Swart leerders. Die verwantskappe wat gevind is tussen fisieke aktiwiteitsvlakke en motoriese behendigheid beklemtoon voorts die waarde van motoriese vaardigheidsontwikkeling in die Liggaamlike Opvoedingklas ten einde die kurrikulum vir Liggaamlike Opvoeding se doelwit om leerders te bemagtig om fisiek aktief te wees, te bereik. Laastens toon die verwantskappe wat gevind is tussen motoriese behendigheid en akademiese prestasie dat die ontwikkeling en instandhouding van motoriese vaardighede in die Liggaamlike Opvoedingprogram in Senior Fase-leerders se kognitiewe ontwikkeling en akademiese prestasie „n rol kan speel. / PhD (Movement Education), North-West University, Potchefstroom Campus, 2015

Fundamentele bewegingsvaardighede is die onderbou of basis waarop al die vereiste vaardighede en aktiwiteite in die kurrikulum vir Senior Fase Liggaamlike Opvoeding van die Kurrikulum en Assesseringsbeleidsverklaring (KABV), gebou is. Dit word verder in die literatuur beklemtoon dat die kwalitiet waarmee leerders „n fundamentele bewegingsvaardigheid uitvoer, net so belangrik is soos die kwantitatiewe uitkoms van die uitvoering. Liggaamlike Opvoedingonderwysers behoort dus bewus te wees van beide die kwalitatiewe en kwantitatiewe vlakke van leerders se fundamentele bewegingsvaardighede in die lig van die vereiste ontwikkeling en inoefening van gespesialiseerde bewegings- en sportvaardighede in die Liggaamlike Opvoedingprogram. Fundamentele bewegingsvaardighede speel verder „n integrale rol in „n leerder se algehele motoriese behendigheid. Die Liggaamlike Opvoeding-onderwyser moet voorts bewus wees van geslags- en etniese verskille in fundamentele bewegingsvaardighede en motoriese behendigheid ten einde effektief in die Liggaamlike Opvoedingprogram te differensieer en by verskillende leerders se vermoëns aan te pas. Verder, aangesien dit die primêre doelstelling van Liggaamlike Opvoeding in die KABV is om leerders te bemagtig om fisiek aktief te wees, is die verwantskap tussen fundamentele bewegingsvaardighede, motoriese behendigheid en fisieke aktiwiteitsvlakke nog „n aspek wat van belang is vir die Liggaamlike Opvoeding-onderwyser in die samestelling van die Liggaamlike Opvoedingprogram. Laastens toon navorsing „n verwantskap tussen motoriese behendigheid en akademiese prestasie. Die doel van hierdie studie was eerstens om die kwantitatiewe en kwalitatiewe stand van fundamentele bewegingsvaardighede by Senior Fase leerders in die Potchefstroom-omgewing te bepaal. Die tweede doelstelling was om die verskille tussen geslagte en etniese groepe ten opsigte van motoriese behendigheid te bepaal. Die derde doelstelling was om die verband tussen motoriese behendigheid en fisieke aktiwiteit te bepaal, en laastens om die verband tussen motoriese behendigheid en akademiese prestasie te bepaal. ʼn Totaal van 239 Senior Fase leerders (98 seuns en 141 dogters), tussen die ouderdomme 13 en 14 jaar het aan die studie deelgeneem. Kwantitatiewe metodologie, met „n eenmalige dwarssnit-ontwerp, is vir die doeleindes van die studie gebruik. Die proefpersone se fundamentele bewegingsvaardighede en motoriese behendigheid is bepaal met behulp van die verkorte weergawe van die Bruininks-Oseretsky Test of Motor Proficiency 2 (BOT-2) (Bruininks & Bruininks, 2005), „n kwantitatiewe toetsbattery wat bestaan uit vier komponente, naamlik fynmotoriese kontrole, manipulasie koördinasie, liggaamskoördinasie en krag-en-ratsheid. Vir die kwalitatiewe bewegingsanalise is van die Fundamentele Bewegingspatroonassesseringsinstrument (FMPAI) (Gallahue & Donnelly, 2003) gebruik gemaak. Vir die meting van fisieke aktiwiteitsvlakke is gebruik gemaak van die gestandaardiseerde International Physical Activity Questionnaire (IPAQ) (Sjöström, 2005). Hierdie vraelys vra die deelnemer om fisieke aktiwiteite van die laaste sewe dae, en ook van ‟n normale week oor die algemeen, gemeet in totale METS (metabolic equivalent – intensiteit van oefening), te rapporteer. Die leerders se akademiese prestasie is gemeet deur gebruik te maak van die gemiddelde akademiese punt (gemiddeld van al die vakke – Afrikaans, Engels, Wiskunde, Lewensoriëring, Geskiedenis, Geografie, Natuur-Wetenskap, Tegnologie, Ekonomiese en Bestuurswetenskappe en Skeppende Kunste), op die leerder se rapport aan die einde van die jaar, asook die gemiddelde punte vir die twee vakke Engels en Wiskunde, soos op die rapport aan die einde van die jaar aangedui. Beskrywende statistiek is gebruik om gemiddeldes ( x ), minimum- en maksimumwaardes, en standaardafwykings (sa) met behulp van die Statistica vir Windows rekenaarprogram (StatSoft, 2012) te bereken. Verbande tussen die kwantitatiewe en kwalitatiewe resultate, tussen die motoriese behendigheidtoetse en die fisieke aktiwiteitsvlakke, asook tussen motoriese behendigheidstoetse en akademiese prestasie is ontleed met behulp van Spearman korrelasiekoëffisiënte. Om die praktiese betekenisvolheid van die verbande te bepaal is die korrelasiekoëffisiënt as effekgrootte (EG) gebruik. Ten einde die betekenisvolheid van geslagsen etniese verskille te bepaal, is die data verder geanaliseer deur gebruik te maak van onafhanklike t-toetse (p<0.05) en vir die doel van die interpretasie van praktiese betekenisvolheid van die verskille is effekgroottes (EG) bereken. Uit die resultate van die studie blyk dit dat daar in die kwantitatiewe evaluasie, veral by die wisselspronge, lynloop en eenbeenstand, agterstande by 20 tot 35% van die leerders was. Met betrekking tot die kwalitatiewe uitvoering van die vaardighede was die eenbeenstand by 22.6 tot 24.5% van die leerders nog nie in die volwasse stadium van bemeestering van fundamentele bewegingsvaardighede nie. Die kwantitatiewe en kwalitatiewe tellings het verder by die bonsen- vang- en die dribbel-van-die-bal toetse nie gekorreleer nie, wat daarop dui dat leerders soms kwantitatief, maar nie noodwendig kwalitatief, aan die norme voldoen het nie. Met betrekking tot verskille tussen geslagte en etniese groepe, toon die resultate dat die meisies oor die algemeen beter as die seuns gevaar het, en die Wit leerders beter gevaar het as die Swart leerders in die fynmotoriese koördinasietoetse. Met betrekking tot liggaamskoördinasie het die Wit leerders betekenisvol beter as die Swart leerders in die wisselsprongtoets gevaar. Betekenisvolle verskille is verder met betrekking tot die krag- en ratsheidkomponent gevind, waar die Wit leerders beter as die Swart leerders in die eenbeenspring-item gevaar het, terwyl onderskeidelik seuns en Wit groepe beter resultate as die meisies en die Swart groepe in die opsit- en opstoottoetse getoon het, asook met betrekking tot die totale motoriese behendigheidstelling (totale BOT-2 telling). Wat die fisieke aktiwiteitsvlakke van die proefpersone betref, toon die totale groep ʼn gemiddelde waarde van 489.68 METS per week, wat as matig-aktief geklassifiseer kon word, terwyl die seuns as hoog-aktief en die meisies as matig-aktief beskou kan word. Daar is ook statisties betekenisvolle korrelasies tussen die fisieke aktiwiteitsvlakke en verskeie motoriese vaardighede gevind, sowel as die totale BOT-2 telling by die totale groep en die seuns en meisies afsonderlik. Die motoriese sub-item waar die sterkste korrelasie met fisieke aktiwiteitvlakke in die totale groep asook by seuns en meisies afsonderlik gevind is, was die liggaamskoördinasie-item van die wisselspronge. Laastens toon die resultate met betrekking tot die verband tussen motoriese behendigheid en akademiese prestasie, betekenisvolle korrelasies tussen die verskillende groepe (seuns, meisies en totale groep) se Engelse, Wiskunde en jaargemiddeld en verskeie sub-items van al die komponente van die BOT-2, naamlik fyn-motoriese kontrole, manipulasie koördinasie, liggaamskoördinasie, krag en ratsheid, asook die totale motoriese behendigheidtelling, alhoewel hoofsaaklik met klein praktiese effekte. Die sterkste korrelasie is by al die groepe tussen die jaargemiddeld, asook die Engels en Wiskunde in ‟n mindere mate, met krag en ratsheid, gevind. Die totale motoriese behendigheidstelling het verder betekenisvol gekorreleer met die jaargemiddeld by al die groepe, met praktiese betekenisvolheid van medium effek. Die resultate van hierdie studie beklemtoon die noodsaaklikheid van die bewustheid van en assessering van die kwantitatiewe en kwalitatiewe stand van leerders se fundamentele bewegingsvaardighede deur die Liggaamlike Opvoeding-onderwyser. Die ontwikkeling en instandhouding van fundamentele bewegingsvaardighede behoort dus in die kurrikulum vir Senior Fase Liggaamlike Opvoeding ingesluit te word, ook met die oog op optimale motoriese behendigheidsontwikkeling. Die Liggaamlike Opvoeding-onderwyser behoort verder die Liggaamlike Opvoedingprogram aan te pas by die motoriese behendigheidsvlakke van die verskillende geslagte en etniese groepe in die klas, met spesifieke aandag aan die liggaamskoördinasievaardighede van Swart meisies en Swart seuns, asook krag- en ratsheidvaardighede by meisies en Swart leerders. Die verwantskappe wat gevind is tussen fisieke aktiwiteitsvlakke en motoriese behendigheid beklemtoon voorts die waarde van motoriese vaardigheidsontwikkeling in die Liggaamlike Opvoedingklas ten einde die kurrikulum vir Liggaamlike Opvoeding se doelwit om leerders te bemagtig om fisiek aktief te wees, te bereik. Laastens toon die verwantskappe wat gevind is tussen motoriese behendigheid en akademiese prestasie dat die ontwikkeling en instandhouding van motoriese vaardighede in die Liggaamlike Opvoedingprogram in Senior Fase-leerders se kognitiewe ontwikkeling en akademiese prestasie „n rol kan speel. / PhD (Movement Education), North-West University, Potchefstroom Campus, 2015

The human body best performs when it is physically active. The consequences of inactivity can bring about many health risks. The purpose of this study was to investigate the relationship between physical activity, waist circumference and medication use among South African men. Men between ages 30 and 65 years (N = 5000, ͞x = 43.2; ± 8.55) were included in this study. With the use of medication, distinction was drawn between various ethnic groups. Subjects selected for this study are members of the same medical aid. The respondents that formed part of a non-random availability population and participated voluntarily were used in this study. According to the results, it appears that out of a total of 4 954 respondents, 58.3% had the lowest incidence of physical activity, 21% were moderately active and 20.7% highly active. WC appears much higher among those that fall within the lowest incidence of physical activity group. No significant difference was observed between moderately and highly active people. There are 11 members in the high Physically Active (PA) category that has the highest WC (X =131.5). When scrutinising the different ethnic groups it is obvious that moderate to high PA is associated with a lower WC. Chronic medication (CM) use is determined on the basis of the registry for chronic medication use of the relevant medical aid. Those who participated in the assessment of waist circumference, CM and PA consisted of 4 964 respondents. In this study distinction was drawn between three medical condition influenced by exercise, namely diabetes, cholesterol and depression and hypertension. The results indicate that CM use is associated with higher WC and reduced kCal consumption. The majority of respondents (78%) do not use medication and 21.9% do. Those that do not use medication showed to have the lowest WC. However, respondents that are highly active and also use CM showed a lower MO than those that are low and moderately active. It can thus be deduced that regular physical activity is directly related to one’s health. / Thesis (MSc (Biokinetics))--North-West University, Potchefstroom Campus, 2013.

The human body best performs when it is physically active. The consequences of inactivity can bring about many health risks. The purpose of this study was to investigate the relationship between physical activity, waist circumference and medication use among South African men. Men between ages 30 and 65 years (N = 5000, ͞x = 43.2; ± 8.55) were included in this study. With the use of medication, distinction was drawn between various ethnic groups. Subjects selected for this study are members of the same medical aid. The respondents that formed part of a non-random availability population and participated voluntarily were used in this study. According to the results, it appears that out of a total of 4 954 respondents, 58.3% had the lowest incidence of physical activity, 21% were moderately active and 20.7% highly active. WC appears much higher among those that fall within the lowest incidence of physical activity group. No significant difference was observed between moderately and highly active people. There are 11 members in the high Physically Active (PA) category that has the highest WC (X =131.5). When scrutinising the different ethnic groups it is obvious that moderate to high PA is associated with a lower WC. Chronic medication (CM) use is determined on the basis of the registry for chronic medication use of the relevant medical aid. Those who participated in the assessment of waist circumference, CM and PA consisted of 4 964 respondents. In this study distinction was drawn between three medical condition influenced by exercise, namely diabetes, cholesterol and depression and hypertension. The results indicate that CM use is associated with higher WC and reduced kCal consumption. The majority of respondents (78%) do not use medication and 21.9% do. Those that do not use medication showed to have the lowest WC. However, respondents that are highly active and also use CM showed a lower MO than those that are low and moderately active. It can thus be deduced that regular physical activity is directly related to one’s health. / Thesis (MSc (Biokinetics))--North-West University, Potchefstroom Campus, 2013.

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.

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.

Physical inactivity, a modifiable risk factor for coronary heart disease (CHD) both in persons with intellectual disability (ID) and non-ID, is considered the fourth leading cause of death in the world. Long-term regular participation in physical activity is associated with a reduced risk for CHD. Literature currently lacks evidence on the effect of long-term physical activity on the functional capacity and risk factors for developing CHD in persons with ID. The purpose of this study was firstly, to determine the effect of a long-term physical activity intervention on the risk factors associated with developing CHD and secondly the effect of a combined aerobic and resistance physical activity intervention on the functional capacity of persons with ID. A cohort of seventy-four (74) participants living in a care facility in Potchefstroom, South Africa, participated in this study, a seven-year follow-up physical activity intervention study. To determine the effect of a seven-year combined aerobic and resistance exercise intervention programme, data was collected in 2006 and in 2013. At baseline (2006) and end (2013), a CHD risk profile was determined by means of a questionnaire and physical assessment. The physical assessment included resting blood pressure, peripheral glucose and cholesterol measurements, and body composition by means of body mass index (BMI), waist-to-hip ratio (WHR) and body fat percentage derived from skinfold measurements. Cardiorespiratory fitness was assessed by means of the adapted sub-maximal YMCA bicycle ergometer protocol from which a physical work capacity (PWC) was calculated. The participants followed a structured physical activity intervention two days per week for at least 45 minutes for a seven year period. The exercise intervention consists of cardiorespiratory exercises, muscle stretches and muscle endurance exercises. All data analyses were performed with SPSS 22.0 (IBM SPSS Statistics, Armonk, NY) statistical analysis software programme. The descriptive statistics (mean and standard deviations) as well as frequencies were calculated to describe the characteristics of the participants and the point prevalence of the CHD risk factors. General Linier Model analyses were applied to determine the significant changes in CHD risk factors measured from baseline to end with adjustment for baseline measurements. McNemar exact test indicated significant changes in the point prevalence of the CHD risk factors from baseline to end. The relationship between the changes in the cardiorespiratory fitness and the measured risk factors were performed with a partial correlation analysis adjusting for age in 2013. The level of significance was set at p ≤ 0.05. The results indicate that the prevalence of inactivity decreased with 50% after the seven-year intervention program. Prevalence of age as a risk factor for developing CHD increased significantly post-intervention from 10% to 18%. Body mass decreased significantly in men (1.25 ± 5.43 kg) and increased significantly in women (0.15 ± 6.83kg). BMI changes reflect changes in body mass of the participants. Body fat percentages increased both in men (2.98%) and in women (0.95%). A significant increase in systolic blood pressure (6.2 ± 10.1 mmHg) for men and diastolic blood pressure (6.35 ± 10.42 mmHg) for women was found. Physical work capacity in both male (1.90 ± 0.73 watt/kg) and female (1.55 ± 0.43 watt/kg) participants decreased to 1.43 ± 0.45 watt/kg and 1.14 ± 0.46 watt/kg respectively during the intervention period. Although a correlation between changes in PWC and the risk factors for CHD was found, none of the correlations was significant when adjusted for age in 2013. The conclusion drawn from this study is that a long-term physical activity intervention in a population with ID reduced the point prevalence for physical inactivity and overweight and obesity, in spite of a decrease in cardiorespiratory fitness. The changes in cardiorespiratory fitness did not relate to the changes observed in the risk factors of CHD. / MSc (Biokinetics), North-West University, Potchefstroom Campus, 2015