Thesis (MASpor)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The purpose of this study was to gain more information on respiratory muscle function of team sports. This was achieved by determining the relationship between anthropometry and respiratory muscle function and the relationship between respiratory muscle function and exercise performance. The degree of respiratory muscle fatigue after a speed endurance test on land and in water was also determined. A total of 62 subjects were tested. The group consisted of 14 netball players (age: 20.9 ± SD 2.0 years; height: 172.5 ± SD 6.1cm and weight: 66.6 ± SD 7.8 kg); 15 rugby players (age: 21.7 ± SD 2.2 years; height: 183.1 ± SD 7.3cm and weight: 92.5 ± SD 13.2 kg); 12 male swimmers (age: 18.9 ± SD 2.5 years; height: 183.3 ± SD 6.5cm and weight: 77.2 ± SD 8.6 kg); 8 female swimmers (age: 17.8 ± SD 1.6 years; height: 168.3 ± SD 5.4cm and weight: 63.9 ± SD 9.8 kg); 7 male control subjects (age: 21.4 ± SD 1.5 years; height: 179.7 ± SD 5.0cm and weight: 80.8 ± SD 10.8 kg) and 6 female control subjects (age: 21.5 ± SD 1.5 years; height: 166.9 ± SD 6.5cm and weight: 60.2 ± SD 6.7 kg). Testing included anthropometric measurements, lung function (FVC test), and respiratory muscle function (baseline MIP, MEP, MVV). Netball -, rugby players and the control subjects performed a speed endurance test on land and the swimmers performed a speed endurance test in the swimming pool. This test was followed by a second MIP measurement 60 and 120 seconds after the sprint endurance test. Respiratory muscle strength showed no correlations to anthropometry for men and women. For men, height, weight, sitting height, biiacromiale breath and waist girth accounted for 17% of the variance in MIP (P = 0.34). The variance in MEP was accounted for 15.6% by height, weight, sitting height, biacromiale breath and waist girth (P = 0.41). For women, weight, sitting height, arm span, biacromiale breath and chest girth accounted for 28.4% of the variance in MIP (P = 0.17), but MEP was accounted for only 22% by sitting height, arm length, arm span and body mass index as well as chest girth (P = 0.32). Respiratory muscle endurance showed correlations to certain anthropometry variables and had a significant regression equations for MVV in men: -312.51 + (2.83 x Arm span) – (0.38 x Sum of 8 skinfolds) and arm span and sum of eight skinfolds accounted for 47.3% of the variance in MVV. Women’s MVV also had a significant regression (P = 0.002): - 106.7 + (1.5 x Body mass) + (1.0 x Arm span) – (0.2 x Sum of 8skinfolds) and weight, arm span and sum of eight skinfolds accounted for 45% of the variance in MVV. Only MIP and MEP had significant correlations (r = 0.63, P < 0.01 and r = 0.66, P < 0.02 respectively) to the speed endurance test on land. Although significant, MVV and FVC showed no correlations to the speed endurance test. Both MIP and MEP had a correlation to the speed endurance test in the water (r = -0.55, P < 0.02 for both). FVC also had a correlation to the speed endurance test, although it was not significant (r = -0.51, P < 0.44). MVV had a poor correlation to the speed endurance test. Sixty seconds after the speed endurance test the land –based group’s (netball and rugby players grouped together) RM were 14.39% fatigued compared to the 9.04% of the water – based group (swimmers) and 41.02% of the control group. One hundred and twenty seconds after the sprint endurance test the land –based group’s RM were 8.43 fatigued compared to the 3.54% of the water –based group and the 24.64% of the control group. In conclusion, anthropometry plays a moderate role in RM endurance but even a smaller role in RM strength. The relationship between RM functions and the speed endurance test varied between the land – and water –based groups, but certain RM function can play a moderate role in the performance in this speed endurance test. All the groups experienced fatigue after the speed endurance test, but the degree was more in the control group followed by the land –based athletes compared to the water –based athletes. This indicates that stronger RM function can lead to less RM fatigue. / AFRIKAANSE OPSOMMING: Die doel van die studie was om die respiratoriese spier funksies van span sporte te bestudeer en is gedoen deur na die verband tussen respiratoriese spier funksies en antropometrie, die verband tussen respiratoriese spier funksies en oefen prestasie en die mate van respiratoriese spier uitputting na oefening te kyk. ‘n Totaal van 62 subjekte is getoets. Die groep het bestaan uit 14 netbal (ouderdom: 20.9 ± SD 2.0 jaar; lengte: 172.5 ± SD 6.1cm en gewig: 66.6 ± SD 7.8 kg); 15 rugbyspelers (ouderdom: 21.7 ± SD 2.2 jaar; lengte: 183.1 ± SD 7.3cm en gewig: 92.5 ± SD 13.2 kg); 12 mans swemmers (ouderdom: 18.9 ± SD 2.5 jaar; length: 183.3 ± SD 6.5cm and gewig: 77.2 ± SD 8.6 kg); 8 dames swemmers (ouderdom: 17.8 ± SD 1.6 jaar; lengte: 168.3 ± SD 5.4cm and gewig: 63.9 ± SD 9.8 kg); 7 mans kontrole subjekte (ouderdom: 21.4 ± SD 1.5 jaar; lengte: 179.7 ± SD 5.0cm and gewig: 80.8 ± SD 10.8 kg) and 6 dames kontrole subjekte (age: 21.5 ± SD 1.5 years; height: 166.9 ± SD 6.5cm and weight: 60.2 ± SD 6.7 kg). Toetsing het die volgende ingesluit: Antropometriese meetings, long funksies en respiratoriese spier funksies (basislyn maksimale inspirasie drukking (MID), maksimale ekspirasie drukking (MED), maksimale willekeuring ventilasie (MWV)). ‘n Spoed uithouvermoë toets op land is deur die netbal –, rugbyspelers en die kontrole subjekte en ‘n uitgevoer en ‘n spoed uithouvermoë toets in die water is deur die swemmers uitgevoer. Beide hierdie toetse is gevolg deur ‘n tweede en derde maksimale inspirasie drukking 60 en 120 sekondes na die toets. Geen korrelasies is gevind tussen antropometrie en respiratoriese spier sterkte vir beide mans en dames. In die geval van mans, het lengte, gewig, bolyf lengte, bi- akromiale breedte en die omtrek van die middel 17% uitgemaak van die variansie in MIP (P = 0.34). Die variasie van MEP is uitgemaak deur 15.6% van lengte, gewig, bolyf lengte, biakromiale lengte en die omtrek van die middel (P = 0.41). Vir dames het gewig, bolyf length, arm reikwydte, bi –akromiale breedte en bors omtrek ’n 28.4% rol gespeel in die variansie van MIP (P = 0.17), maar die variasie in MEP is voorspel met 22% deur bolyf length, arm length, arm reikwydte, liggaams massa indeks en bors omtrek (P = 0.32). Respiratoriese spier uithouvermoê het ‘n korrelasie getoon met sekere antropometriese veranderlikes en ‘n statisties beduidende vergelyking vir mans MWV: -312.51 + (2.83 x Arm reikwydte) – (0.38 x Som van 8 velvoue) waar arm reikwydte en som van ag velvoue was verantwoordelik vir 47.3% van die variansie in MWV. Die dames se MWV het ook ‘n statisties beduidende vergelyking getoon: MWV = -106.7 + (1.5 x gewig) + (1.0 x Arm reikwydte) – (0.2 x Som van 8 velvoue) waar gewig, arm reikwydte en die som van ag velvoue verantwoordelik was vir 45% van die variansie in MWV. Slegs MID en MED het statisties beduidende korrelasies ( onderskeidelik r = 0.63, P < 0.01 and r = 0.66, P < 0.02 ) getoon met die spoed uithouvermoë toets op land. Geen korrelasie is tussen MWV en die geforseerde vitale kapasiteit toetse gevind al was die verband statistiese beduidend. Beide MID en MED het ’n korrelasie met die spoed uithouvermoë toets in die water getoon (r = -0.55, P < 0.02 vir beide). Die geforseerde vitale kapasiteit toets het ook ’n korrelasie met die spoed uithouvermoë toets, tog was dit nie statisties beduidend nie (r = -0.51, P < 0.44). MWV het geen korrelasie getoon met die spoed uithouvermoë toets op land. Sestig sekondes na die spoed uithouvermoë toets is ’n 14.39 % respiratoriese spier uitputting in die land gebaseerde groep (netbal – en rugby spelers), 9.04% respiratoriese spier uitputting in die water gebaseerde groep (swemmers) en ’n 41.02% respiratoriese spier uitputting in die kontrole groep gevind. Na 120 sekondes was die respiratoriese spiere van die land gebaseerde groep steeds 8.43% uitgeput in vergelyking met die 3.54% van die water gebaseerde groep en die 24.64% van die kontrole groep. Dus speel antropometrie ‘n matige rol in respiratories spier uithouvermoë en selfs ‘n kleiner rol in respiratoriese spier sterkte. Die verband tussen respiratoriese spier funksies en die spoed uithouvermoë toets het gevarieer tussen die land – en die water gebaseerde groepe, maar respiratoriese spier funksies kan ‘n matige rol speel in die voorspelling van die prestasie in die spoed uithouvermoë toets. Die kontrole groep het meer respiratoriese spier uitputting ervaar na die spoed uithouvermoë toets, dus beteken dit dat geoefende en ongeoefend persone respiratoriese spier uitputting sal ervaar.

Research has clearly shown that all individuals will benefit from regular physical activity. Unfortunately, young adults including college and university students are not physically active on a regular basis worldwide. In the developing world particularly in Sub- Saharan Africa, physical inactivity along with tobacco use, poor diet and nutrition are increasingly parts of today&rsquo / s lifestyle. Physical activity declines with age and the most important decline appear to be during the transition period from high school to university and during university years. The aim of this study was to assess the level of physical activity, to investigate the perceived constraints to physical activity and to determine whether socio-demographic characteristic have an influence on participation in physical activity and perceived constraints to physical activity among paramedical institutions students in Uganda. A cross-sectional study with descriptive quantitative design was conducted. Four hundred (400) paramedical institution students were selected using a stratified random sampling technique. A self-administered questionnaire adopted from the literature was used to collect the data. A response rate of 90% was obtained. Descriptive and inferential statistics using the statistical package for social sciences were used to analyze the data. The relationships and associations between different variables were determined by carrying out significant tests using chi-square tests. Alpha level was set at 0.05. The mean age of the sample was 22.44 years (SD = 2.03). Males constituted 73.9% and females constituted 26.1% of the sample. Students from eight (8) health professional courses participated in the study. Over half (59%) of participants were classified as physically active and 41% were classified as inactive or sedentary. For male participants, lack of the right equipment to exercise and wanting to do other things in their free time were perceived as the major constraints to physical activity. For female participants, lack of motivation and tiredness after exercise were perceived as the major constraints to physical activity. The findings of this study demonstrate that there is an influence of socio-demographic characteristics such as gender, year of the study and different departments/schools on participation in physical activity and perceived constraints to physical activity. They also indicate the need of health promotion intervention aiming at promoting physical activity among paramedical institution students in Uganda.

The purpose of this investigation was to determine the effects of post-exercise carbohydrate-protein feedings on muscle glycogen restoration following exhaustive cycle ergometer exercise. Seven male collegiate cyclist (age=25.6±3.3y, ht.=180.9±8.5cm, wt.=75.4±10.7kg, VO2max=4.20±0.4 1•miri 1) performed three trials, each separated by -lwk, 1) 100% (x-D glucose (CHO), 2) 70% carbohydrate-20% protein-10% fat (CHOPRO), and 3) 86% carbohdyrate-14% amino acid (CHO-AA). All feedings were eucaloric, based upon 1.0 g•kgb.W.'1•hr"1 of carbohydrate, and administered every half hour during a four hour muscle glycogen restoration period in an 18% wt./vol. solution. Muscle biopsies were obtained immediately and four hours post exercise. Following the exhaustive exercise and every half hour for four hours a blood sample was drawn. Muscle glycogen concentrations increased 53%, 47%, and 57% for the CHO, CHO-PRO, and CHO-AA feedings, respectively, however no differences among the feedings were apparent in muscle glycogen restoration. The plasma glucose and insulin concentrations demonstrated no differences throughout the restoration period among the three feedings. These results suggest that muscle glycogen restoration does not appear to be enhanced with the addition of either protein or amino acids to an eucaloric carbohydrate feeding following an exhaustive cycle exercise. However, it appears that if adequate amounts of carbohydrates are consumed (greater than 0.70 g•kgb,W,."'•hf' carbohydrate) following exhaustive exercise, maximal muscle glycogen restoration occurs. / School of Physical Education

Reductions in baroreflex responsiveness have been thought to increase the prevalence of orthostatic hypotension in endurance trained athletes. To test this hypothesis, cardiovascular responses to orthostatic stress, cardiopulmonary and carotid baroreflex responsiveness, and the effect of cardiopulmonary receptor deactivation on carotid baroreflex responses were examined in 24 men categorized by maximal aerobic power (V02max) into one of three groups: high fit (HF, V0-2max=67.0±1.9 ml•kg^-1•min^-1), moderately fit (MF, V0-2max=50.9±1.4 ml•kg^-1•min^-1), and low fit (LF, V0-2max=38.9±1.5 ml•kg^-1•min^-1). Orthostatic stress was induced using lower body negative pressure (LBNP) at -5, -10, -15, -20, -35, and -50 torr. Cardiopulmonary baroreflex responsiveness was assessed as the slope of the relationship between forearm vascular resistance (FVR, strain gauge plethysmography) and central venous pressure (CVP, dependent arm technigue) during LBNP<-35 torr. Carotid baroreflex responsiveness was assessed as the change in heart rate (HR, electrocardiography) or mean arterial pressure (MAP, radial artery catheter) elicited by 600 msec pulses of neck pressure and neck suction (NP/NS) from +40 to -70 torr. Pressures were applied using a lead collar wrapped about the subjects' necks during held expiration. Stimulus response data were fit to a logistic model and the parameters describing the curve were compared using two-factor ANOVA. The reductions CVP, mean (MAP), systolic, and pulse pressures during LBNP were similar between groups (P<0.05). However, diastolic blood pressure increased during LBNP m all but the HF group. (P<0.05). The slope of the FVR/CVP relationship did not differ between groups, nor did the form of the carotid-cardiac baroreflex stimulus response curve change during LBNP. changes in HR elicited with NP/NS were not different between groups (£>0.05). The range of the MAP stimulus response curve, however, was significantly less in the HP group compared to either the MP or LF group (£<0.05). These data imply that carotid baroreflex control of HR is unaltered by endurance exercise training, but carotid baroreflex control of blood pressure is impaired significantly, predisposing athletes to faintness.

In cerebral palsied adults, the cardiovascular responses to different types of exercise have not previously been ascertained. Therefore, the purpose of this study was to determine the blood pressure and heart rate responses of adults with cerebral palsy to static muscular contractions and to dynamic muscular contractions. Fifteen adults with cerebral palsy and 15 able-bodied adults (average age for each group = 30 years) performed a static exercise protocol and a dynamic resistance exercise protocol using each limb (or the limbs capable of meeting the requirements of the exercise protocol). Heart rate and blood pressure were assessed before, during, and after each exercise bout with each limb. During the static exercise protocol, each subject performed static contractions at 40% of maximal voluntary contraction to fatigue. The dynamic exercise protocol for each limb consisted of three 20-second bouts of hydraulic resistance exercise each of which was followed by 20 seconds of rest. No differences were found between the two groups of subjects in heart rate and blood pressure during static exercise. In dynamic exercise, however, the trend in heart rate from bout to bout differed between the groups. In addition, the cerebral palsied group's diastolic pressure was higher than that of the able-bodied group at the end of dynamic exercise. The findings of this study indicate that although the heart rate and blood pressure responses to dynamic resistance exercise in the cerebral palsied subjects differed from the responses of the able-bodied subjects, healthy adults with cerebral palsy may safely perform both static and dynamic resistance exercise. More research using this disabled population is needed so that guidelines for prescribing exercise for adults with cerebral palsy may be developed.

The purpose of this investigation was to examine the change in pulmonary ventilation (V_E), ventilatory equivalent of oxygen (VE_O_2) and lactic acid (LA) in relation to oxygen uptake (V_O_2) as predictors of the lactate threshold (LT). Eight healthy male (21.9 ± 3.0 years) subjects conducted three incremental-load tests. In each test the initial work rate consisted of 4 minutes of unloaded pedaling ("0" load) followed by incremental-load work of 360 Kgm • min^-1 at 60 rpm for trial I and trial II, while during trial III the work rate consisted of 540 Kgm • min^-1 of incremental-load work at 90 rpm. Work load was increased every third minute until the subject reached voluntary exhaustion. Blood samples from a forearm vein were collected during trial II (60 rpm) and trial III (90 rpm) and analyzed for lactic acid. In our subjects the measured (x̄ ± SD) lowest VE_O_2 for O_2 in relation to V_O_2 for trial I of 22.9 ± 1.9 occurred at a V_O_2 of 1.27 ± 0.8 L • min^-1. For trial II the VE_O_2 of 22.4 ± 1.3 occurred at a V_O_2 of 1.30 ± 0.09 L • min^-1, while for trial III a VE_O_2 of 24.4 ± 2.5 occurred at a V_O_2 of 1.84 ± 0.15 L • min^-1. The lowest VE_O_2 and onset of LA accumulation as calculated from individual exponential equations relating V_E to V_O_2 yielded V_O_2 values at 1.77 ± 0.18 L • min^-1 and 1.74 ± 0.25 L • min^-1 for trial II, and 1.83 ± 0.19 L • min^-1 and 2.02 ± 0.53 during trial III. Utilizing ln[LA]-ln V_O_2 equations, the LT occurred at a V_O_2 of 1.30 ± 0.07 L • min^-1 during trial II and 1.85 ± 0.12 L • min^-1 during trial III. It was concluded that during the 60 rpm test that the lactate threshold was best predicted by measured lowest VE_O_2 and the plot of the In[LA] to In V_O_2 relationship. The methods used in this study provide a valid and reliable estimate of the lactate threshold and support the use of measured lowest VE_O_2 , a respiratory gas exchange measure, as an indirect measure of the lactate threshold.

In this study the effects of age (18-55 years), differing levels of fitness (VO 2max ranging from 35.5 to 68.8ml.kg-1.min-1) and endurance training (10 weeks) on heart rate control were investigated. Fitness level was initially determined by a VO2max stress test, succeeded by cold hand and cold face pressor test of autonomic activity. Following these baseline measurements, the subjects (32 nonsmoking male volunteers) were endurance-trained three to four times a week for a 10-week period. The baseline tests were readministered following the 10-week dynamic exercise training period. These data suggest that a natural consequence of aging is a diminishment of autonomic heart rate control; however, endurance training appears to interrupt the aging influence. Individuals of low fitness level appear to have heart rate control dominated by the sympathetic system, while individuals with high fitness levels have a vagally dominated heart rate control system.

Achieving adequate and appropriate recovery from exercise is essential in ensuring optimal performance during repeated bouts of exercise. The use of various recovery interventions has become popular in an attempt to enhance subsequent performance and accelerate post-exercise recovery. The application of various post-exercise hydrotherapy interventions has become increasingly popular, however, the majority of current recovery practices appear to be based largely on anecdotal evidence as opposed to rigorous scientific research or evidence based findings. Physiologically, various hydrotherapy protocols have been shown to affect the body via fluid shifts (interstitial to intravascular space), changes in blood flow and cardiovascular function, and reductions in oedema. The possible psychological effects of water immersion must also be considered, with athletes commonly reporting reduced sensations of fatigue and soreness following immersion. Current literature suggests both hydrostatic pressure and water temperature to be important factors influencing the success of hydrotherapy. The overall aim of the present thesis was to enhance current knowledge and understanding with regards to the physiological and performance effects of various forms of hydrotherapy, used as a post-exercise recovery intervention. Initially, four cold water immersion interventions were compared to active recovery, performed between two bouts of high intensity cycling in hot environmental conditions. Effectiveness of recovery was determined via performance in a subsequent exercise bout; in addition, core body temperature, lactate, and heart rate were recorded. The remaining studies were designed to investigate the effects of cold water immersion, hot water immersion, contrast water therapy, and passive recovery 4 (control) following exercise-induced fatigue and exercise-induced muscle damage. Rate of recovery was assessed through changes in performance, core body temperature, thigh girths, blood markers, and perceived exertion/soreness. The results of the combined studies indicate cold water immersion to be more effective than active recovery when performed immediately post-exercise between two bouts of high intensity cycling in hot environmental conditions. Additionally, both cold water immersion and contrast water therapy were effective in aiding recovery from exercise-induced fatigue and exercise-induced muscle damage. Performance variables indicated an improved maintenance or return of performance following these recovery protocols. The present studies have provided additional information to the limited knowledge base regarding the effect of post-exercise hydrotherapy interventions, specifically, the effect of such interventions on subsequent athletic performance. In conclusion, cold water immersion and contrast water therapy appear to be superior to hot water immersion, active recovery, and passive recovery following fatiguing and muscle damaging exercise. Functional and physiological recovery was enhanced following the use of these two recovery protocols.

Many Americans do not engage in the recommended amount of physical activity, and thus do not receive the potential physical and mental health benefits from physical activity. Stage of change is a model that categorizes individuals into one of five stages based on behavior and intentions for future behavior. This model is useful for promoting physical activity because it allows for tailoring of interventions to individuals with different physical activity levels and readiness for change. The main purpose of this research was to test if more adaptive scores for Essential Self-Regulation Model (ESRM) constructs are found for persons in higher stages of change. Analyses included 96 Western Kentucky University faculty and staff to test the hypothesis that as stage of change increases, the more adaptive the scores will be in regard to the ESRM constructs, including: self-determination (i.e., subtypes of motivation), self-efficacy, attributions, goal setting, strategy use, and self-monitoring. The results supported this hypothesis for intrinsic, integrated, and identified subtypes of motivation, cost, self-efficacy, and goal setting. Constructs that were not significant but had results in the hypothesized direction were introjected and amotivated subtypes of motivation, strategy use, and selfmonitoring. Attribution scores resulted in the opposite of the hypothesized direction. Conclusions, limitations, implications, and suggestions for future research are discussed.

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