Masters Degrees (Biokinetics, Exercise and Leisure Sciences)

Permanent URI for this collectionhttps://hdl.handle.net/10413/6723

Browse

Now showing 1 - 20 of 37

Attitudes towards physical education in KwaZulu-Natal.
(1996) Thomson, Janet Elizabeth.; Andrews, Barry Craig.
This study investigated the attitudes towards Physical Education in KwaZulu and the determinants of those attitudes. The focus was on the teaching of the subject in schools and colleges of education in the KwaZulu Department of Education and Culture. The purpose of the study was to establish whether Physical Education was being limited by a lack of resources and/or the perceived low status of Physical Education. Questionnaires were developed for four different groups, namely, teachers, principals, college lecturers and the pupils and students themselves. The analysis of the responses indicated that all four groups held strong beliefs about the benefits of the subject. The benefits which the pupils regarded as the most positive were in the areas of physical fitness and social development. In contrast to their western counterparts, pupils and students did not view Physical Education as a "light relief' subject nor did they regard enjoyment as a requisite. Negative determinants of attitude were found to be related primarily to the lack of facilities and the consequent lack of diversity in the Physical Education curriculum. Respondents from the teachers' and principals' groups revealed that the teaching of Physical Education in KwaZulu was important but severely inhibited by a combination of factors. Allocation of resources in the form of physical facilities and equipment was found to be deficient. There was an absence of qualified staff, which resulted in the subject either being omitted from the curriculum or being taught by teachers with no knowledge of its objectives nor of the correct teaching methods. In some cases the subject was confused with sport and coaching school teams and in most cases the subject played a subservient role to that of examination subjects. The promotion prospects of the Physical Education teachers were not perceived to be limited compared to their academic counterparts because all of them were teaching academic subjects. Those with specialised training in Physical Education were not in evidence because they were not teaching Physical Education. College lecturers were specialist trained and indicated a much greater degree of success in the implementation of Physical Education programmes. Colleges had superior facilities and equipment although insufficient use of funds was apparent. College lecturers did not feel that they successfully achieved the educational objectives of the subject. In agreement with their western counterparts, they perceived their promotion prospects to be limited. The failure to implement successful programmes of Physical Education in the schools led to the recommendation that preservice specialised training was vitally important but not sufficient and that in-service courses in the form of practical workshops for staff and principals were essential in order to support the preservice initiatives.
Anthropometric characteristics and physiological performance variables of male and female junior hockey players in KwaZulu Natal.
(1997) Amra, Mohamed.
Anthropometric measures, physiological variables and skills tests were performed on subjects selected from the provincial KwaZulu Natai Junior Hockey teams in South Africa. The main purpose of this study was to establish a data base of norms for boy and girls in the UB, U14, U16, UI8 and the U2I age groups. The tests were done at the beginning and at the end of season. The anthropometric measures included height, weight, percentage body fat and lean body mass; physiological variables included sit-ups, push-ups, sit-and-reach (flexibility), broad jump, winder and bleep tests , and the skills tests comprised a wide range of ball skill tests. As expected, anthropometric changes were observed across the age groups, due to growth. Amongst the older age groups the girls had reached height and weight values comparable to elite female players , but only the boys in the U2I had reached their adult height and were slightly taller than the elite male players. There was no significant difference in the profile between the attack and defence players in the boys, but amongst the girls the defence players tended to be heavier and taller than the attack players. In the physiological and skills tests there was no difference between positional players. In the comparison between pre and end season to determine the effectiveness of the training programmes, there was a change in the anthropometric characteristics because of growth. However, the physiological and skill tests revealed no consistent pattern of improvement in the test results from pre season to end season. This study provides the first set of norms for male and female junior hockey players in South Africa. Further studies are required to expand upon and update the data in the current study.
The effects of high intensity exercise on lymphocyte DNA and antioxidant status in trained athletes.
(1998) Govender, Sumentheran Nadarajan.; Chuturgoon, Anil Amichund.; Mars, Maurice.
Apoptosis (programmed cell death) and exercise immunology have been the focus of research for the past five years. Trained athletes are particularly susceptible to a wide variety of viral and bacterial infections and this has been related to oxidative damage which is a mediator of apoptosis. Apoptosis, a normal physiological mechanism has also been implicated in the pathogenesis of a wide-variety of diseases. To date, the link between apoptosis and exercise has not been shown by established methods or ultrastructurally. The objective of the study was t.o determine the effects of a single bout of high intensity exercise on lymphocyte DNA and antioxidant status in trained athletes. The study was carried out in two phases. In the first phase, 11 trained athletes were subjected to a treadmill run to exhaustion using a ramp protocol to determine their maximum oxygen uptake (V02 max). Fifteen millimetres of blood was collected before exercise, immediately after exercise, 24 hours and 48 hours after exercise. Whole blood (4 ul) was used in the determination of DNA damage in lymphocytes using the single cell gel electrophoresis (SCGE) assay. The remaining blood was centrifuged and used for the following: Vitamin C concentration was determined by the 2,4 dinitrophenylhydrazine method, vitamin E concentration was determined by the High Pressure Liquid Chromatography (HPLC) method and lipid peroxides were determined by the measurement ofhydroperoxides. In the second phase, 3 trained athletes who had participated in phase 1, were subjected to a V02 max. test. Blood samples (10 ml) were collected before and immediately after exercise, 24 hours and 48 hours later. Lymphocytes were isolated using Histopaque 1077. An in situ cell death detection kit, Fluorescein was used for the detection and quantification of apoptosis in lymphocytes at a single cell level, based on labelling of DNA strand breaks. Analysis was carried out using flow cytometry. Lymphocytes were also prepared for Transmission Electron Microscopy (TEM) using conventional techniques. The results showed that immediately after exercise there was a non-significant decrease in vitamin C concentrations (p=o, 16), and a non-significant increase in vitamin E (p=0,82) and lipid peroxide concentrations (p=0,21). There was no significant difference in all 3 levels over the 48 hour period, when compared to the pre-exercise values. The SCGE assay revealed that the immediate post exercise samples showed DNA damage in lymphocytes of all subjects as evidenced by fluorescent strands of DNA outside the cell while DNA damage was observed in only one subsequent sample. In the pre-exercise samples, DNA was visualised as a central core, whereas in all samples taken after exercise, DNA was located at the periphery or confined to one pole of the cell. The pattern of DNA distribution seen in the SCGE assay over the 48 hour period were characteristic features of apoptosis. Flow cytometric analysis showed an increase in apoptosis in lymphocytes immediately after exercise with a further increase after 24 hours. After 48 hours the numbers decreased to control levels. TEM showed that majority of cells were normal before exercise while other lymphocytes were smaller with indented nuclei. Immediately after exercise the lymphocytes displayed features of indented nuclei and microsegregation, cell shrinkage, swelling of the endoplasmic reticulum, mitochondria and Golgi. These changes persisted after 24 hours but were not observed after 48 hours when most of the cells showed normal morphology. The ultrastructural changes observed were also characteristic features of apoptosis. These results suggest that high intensity exercise may cause an increase in apoptosis as evidenced by DNA damage in the SCGE assay and fully supported by the results achieved during flow cytometry and by the ultrastructural changes observed.
A comparison of the fitness levels of Indian high school boys in two cohorts : 1977 and 1997.
(2000) Naidoo, Krishnaveni.; Coopoo, Yoganathan.
The main aim of this study was to compare fitness levels of Indian high school boys in two cohorts: 1977 and 1997. A secondary aim was to identify if the same problem areas or strengths still exist in 1997 as in 1977 or if the levels of fitness have further deteriorated or improved, as well as the establishment of norms for boys 14 - 18 years. Ten different Secondary schools from the Durban Metropolitan area participated in this study. The test battery included eight tests measuring four components of motor fitness based on the Fleishman study. The tests that were used consisted of fifty metre shuttle run, fifty metre dash, sit-ups, pull-ups, medicine ball put, shot-put, 250m shuttle run and 12 minute run/walk test. Data from 500 hundred boys were included in the research analysis and these were categorized into 5 different age groups, 13,6 - 14,6 years; 14,7 - 15,6 years; 15,7 - 16,6 years; 16,7 - 17,6 years and 17,7 - 18,6 years. Basic statistical procedures were used to determine the normality of the samples for height and weight in each age group. Standard score tables were drawn for each age group. A paired t-test was used to determine if a significant difference between the means existed. The level of significance was set at 0,05. The means of both studies were compared to ascertain the difference in fitness levels in the two cohorts. The analysis of the data revealed that the fitness status of adolescent boys have deteriorated over two decades.
Physiological and physical fitness profiles of elite South African surfers.
(2000) Patterson, Dean Kenneth.; Coopoo, Yoganathan.
The present study profiled the fitness characteristics of elite South African surfers. Sixty-one surfers volunteered to participate in the study. Each subject underwent a maximal tests in order to measure peak maximum oxygen uptake, anthropometery, co-ordination, agility, balance, Wingate test, and isokinetic strength assessments of the knee and shoulder in extension and flexion, including shoulder internal and external rotation. Lung function measurements were also measured to assess the lung capacity of the subjects. The cardiovascular demands of surfing was high showing a peak VO2 of 54.9 (+SD=9.73) ml.kg-1.min-t, and a peak VE of 98.3 (+SD=17.8) l.min-1. Actual lung function results obtained by the subjects were greater than predicted scores for age and weight. Anaerobic scores were excellent for surfers as compared to other sportpersons. Balance and agility scores were excellent. Good strength ratios and values were obtained through isokinetic testing, both for the shoulders and the knees. The subjects showed an above level of fitness in all the measurements as compared to other water-based athletes. As a result the research showed that surfing can be best enhanced through the principle of specificity, and that the subjects engaged in this sport can be regarded as elite athletes.
The Effect of exhaustive exercise on lymphocyte apoptosis.
(2001) Chetty, Ananthan.
Post exercise lymphocytopenia is a well documented phenomenon. Studies have reported exercise induced DNA damage in leucocytes and have postulated a possible link to apoptosis. Five subjects of differing fitness levels underwent a ramped treadmill test to exhaustion. Venous sampling was undertaken before, immediately post exercise, and 24 and 48 hours after exercise. Single cell gel electrophoresis showed evidence of single strand DNA breaks (as evidenced by an increase in tail moment measurements using the comet assay) in 100% oflymphocytes immediately after exercise, and in the 24 hour and 48 hour post exercise samples. Flowcytometric analysis oflymphocytes revealed a minimal amount of both apoptosis and necrosis at all time intervals. Lymphocyte apoptosis has again been demonstrated after exercise, however the percentage of apoptosis was a maximum of 4.8% at 24 hours. These findings may in part account for the exercise induced lymphocytopenia and reduced immunity demonstrated by numerous previous other studies.
The effects of exercise on the aged.
(2002) Ellapen, Terry Jeremy.; Coopoo, Yoganathan.; Ramiah, Pramila Devi.
This study aimed to document the effects of regular exercise and physical activity on the aged. Subjects (n=S8) over the age of sixty-five participated in the study. All subjects were patrons from various retirement centers of the DAFTA organization (Durban Association for the Aged). The subjects completed a PAR-Q and informed consent form, which allowed the eligible to participate in the study. A pre and post-test battery was administered to measure the following parameters; body mass, height, girth measurement, agility and dynamic balance, muscle strength and endurance, flexibility, co-ordination, dynamic grip strength and aerobic capacity. During the experimental period the subjects engaged in a structured intervention exercise programme of 30 weeks. The intervention programme composed of games, walking, stretching, flexibility and resistance training exercises aimed at improving the following fitness components; agility and dynamic balance, strength, flexibility, co-ordination and aerobic capacity. Inferential and differential statistical methods were employed in order to analyzethe data. The study indicated that regular exercise and physical activity positively impacted the senior citizens' functional capacity and improved their quality of life (p
A Comparison of upper and lower limb exercise in canoeists using the heart rate and oxygen consumption relationship
(2003) Gomes, Adrian Neil.; Mars, Maurice.
The heart rate achieved with maximal upper limb exercise is quoted as being on average thirteen beats per minute lower than when performing maximal leg exercise. Many canoeists use heart rate monitors during training and seek advice on setting their heart rate training zones. Existing guidelines are based on lower limb-derived heart rates, which may not be appropriate. As canoeists use predominantly their upper limbs during canoeing, it was hypothesized that as their upper limbs are trained, they may achieve heart rates and oxygen consumption similar to those achieved with lower limb exercise. The purpose of this investigation was to compare the relationship between heart rate and oxygen consumption when exercising on either a kayak ergometer or treadmill. Fifteen volunteer canoeists, who compete regularly, were recruited by convenience, purposive sampling and randomly allocated to a V02max test using open circuit spirometry, on either a kayak ergometer or treadmill. They returned within 5 to 7 days for a V02max test on the other apparatus. Their heart rates were also measured during these activities. The heart rate oxygen consumption relationship for upper and lower limb exercise was then analysed. Maximum heart rate was on average only 6 beats per minute lower with upper limb exercise, with some subjects achieving the same or very similar HRmax; the median difference in heart rate maximum was only 4 beats per minute. Although the response of heart rate and oxygen consumption to kayaking and running was similar at any given workload, the heart rate on the kayak was about 8 beats per minute higher at any submaximal workload. V02max. on the kayak was lower than on the treadmill. At any metabolic equivalent, the tidal volume was lower on the kayak and there was a lower respiratory rate on the treadmill. At any tidal volume, the metabolic equivalent was lower on the kayak ergometer. The minute volume on the kayak was higher than on the treadmill, for all but the highest intensities of exercise. Using the leg heart rate max to determine the training zones, a slightly higher (negligible) percentage of arm V0max is achieved at any given percentage heart rate. Kayakers who train regularly, appear to be able to attain similar maximum heart rates with upper and lower limb exercise, but a lower V02max when exercising with their arms. The heart rate oxygen consumption response is the same for upper and lower body exercise; and a reduced HRmax and increased heart rate at any sub maximal workload do not appear to apply to canoeists. It is therefore concluded that heart rate training zones based on leg HRmax are suitable for kayak training. This study has helped distinguish the difference between the heart rates of the upper and lower limbs at any given oxygen consumption in canoeists. The benefits of performing this study have also been to provide better advice to canoeists on how to train using heart rate monitors.
The effect of an anti-inflammatory homeopathic product on cytokine status in venous blood following 90 minutes of downhill running.
(2008) Docrat, Aadil.; Peters-Futre, Edith Margret.
Background: Downhill running involves eccentric contractions of the gluteal, quadriceps, hamstring and calf muscles and the lengthening of muscle fibres as they contract. Several studies have demonstrated that this type of prolonged eccentrically biased exercise induces tissue damage and subsequent enhancement of an inflammatory response. Traumeel® S (Heel GmbH, Baden-Baden, Germany) is a homeopathic-complex used to treat trauma and inflammatory processes that is sold as an over the counter remedy in pharmacies. Although the antiinflammatory and analgesic effects of Traumeel® S have been demonstrated in selected clinical trials as well as in in vitro experimental models, little is known of its scientific mechanisms of action. Aim: The aim of this study was to establish whether administration of Traumeel® S five days before and three days after a 90-minute downhill treadmill run at 75% V02 peak significantly changes systemic markers of the inflammatory response. These are to include blood-borne concentrations of Cortisol and examples of selected T-helperrcell cytokines, T-helper2-cell cytokines, chemokines and pro-inflammatory cytokines during the three days following the 90-minute downhill run. Method: This study was designed as a double-blinded, placebo-controlled clinical trial in which matched subjects were randomised to Traumeel (TRAU) and Placebo (PLAC) pairs and exposed to two 90-minute downhill running trials. Twenty subjects (12 men, 8 women) aged between 20 and 50 years, fully complied with all inclusion criteria set for the study. Following baseline laboratory and field testing, they were matched according to gender, body mass index (BMI), training age, training status, peak running performance and foot-strike patterns and randomized into TRAU and PLAC groups. One Traumeel® S tablet was ingested three times per day for five days prior to and three days following a 90-minute downhill run on a treadmill at a -6% gradient and at a speed eliciting 75% V02 peak on a level gradient. Blood samples were obtained immediately before the 90-minute trial (PRE), immediately after the trial (IPE) and 24 hours (24 PE), 48 hours (48 PE) and 72 hours (72 PE) following the trial. Each subject was also requested to complete a training record prior to the trial and keep a record of the daily symptoms of delayed onset muscle soreness (DOMS) both at rest (general pain) and while walking (daily living). Full blood counts, serum creatine kinase (CK) and Cortisol concentrations were determined using standard haematological laboratory procedures. A sandwich ELISA was used to determine plasma interleukin-6 (IL-6) concentrations. A commercial bead-array kit was used to conduct flow cytometric analysis of Interleukin-8 (IL-8), Interleukin-10 (IL-10), Tumour Necrosis Factor alpha (TNFa), and Interleukin-12p70 (IL-12p70) concentrations. Results: Paired student Mests indicate that the mean ± SEM of the two groups was not significantly different (p < 0.05) in terms of age, BMI, percentage body fat, training age, foot strike patterns, running performance, FVC, FEV1; baseline heart rate and blood pressure, RERmax, V02 peak, VEmax, or training status. Although the TRAU group completed the 90-minute downhill running trial at a significantly faster speed (13.3 ± 2.1 vs. 12.8 ±0.3 km.hr; p = 0.02) and covered a greater distance (20.1 ± 0.3 vs. 19.34 ± 0.4; p = 0.03), mean and maximum heart rate and RPE did not differ between trials in the TRAU and PLAC groups. The downhill running protocol resulted in significant increases in neutrophil counts and creatine kinase, Cortisol, IL-6, IL-8 and IL-10 concentrations in the circulation (n = 20; p < 0.001). When comparing the TRAU (n = 10) and PLAC (n = 10) groups, blood neutrophil counts, creatine kinase, Cortisol, and IL-6 concentrations over the 5 time points and PRE, IPE and 24 PE plasma TNF, IL-8, EL-10 and EL-12p70 concentrations did not differ significantly (p > 0.05). Blood creatine kinase was, however, significantly higher in the TRAU group at 24PE (p < 0.05). The post-trial DOMS scores reported by the TRAU group over the 3-day post-exercise recovery period were also significantly lower in the TRAU group at 24PE (p = 0.03). Conclusion: Despite a faster running speed and higher post trial CK concentration in the TRAU group following the 90-minute downhill run, statistically significant differences in circulating stress hormone, and cytokine concentrations (IL-6, IL-8, IL-10, TNFa and IL-12p70) between the TRAU and PLAC groups, were not identified. Delayed onset muscle soreness was also significantly lower in the TRAU group at 24 hours post trial (p = 0.03). While these findings would support attenuation of the post-exercise inflammatory response by Traumeel® S, further work is required to verify this possibility.
The effect of an anti-inflammatory homeopathic product on systemic markers of inflammation following 90 minutes of downhill running.
(2008) Smith, Megan.; Peters-Futre, Edith Margret.
Background: The homeopathic preparation, Traumeel S, has been used as a valuable alternative to conventional non-steroidal anti-inflammatory drugs (NSAIDS) for over 30 years. This antihomotoxic, anti-phlogistic drug has been widely used by sportsmen and women in the treatment of lesions and inflammatory processes which result from exercise-induced skeletal muscle microtrauma. Although numerous randomised, double-blind placebo-controlled trials have confirmed the efficacy of Traumeel S as an anti-inflammatory agent, there are few in vivo studies which have specifically investigated the mechanism by which Traumeel S is effective in reducing inflammatory response to exercise-induced muscle cell damage. Aim: To establish whether the administration of Traumeel S during the five days before participation and three days following participation, significantly attenuates the systemic markers of the inflammatory response, following a 90-minute downhill running trial. Method: Twenty-four healthy athletes (14 men and 10 women), aged 20-50 years, were recruited for this study. Following baseline laboratory testing and familiarisation with the treadmill as well as a field test, subjects were matched according to gender, BMI, training age, training status, peak performance and foot strike patterns and randomised into Traumeel (TRS) and Control (PLAC) groups in a placebo-controlled, double-blind design. One Traumeel S or Placebo tablet was ingested three times per day for five days prior to and three days following a 90-minute exercise trial on a downhill (-6% gradient) at 75% V02 max- Blood samples were collected prior to the 90-minute trial (PRE), immediately after the trial (IPE) and 24 hours (24 PE), 48 hours (48 PE) and 72 hours (72 PE) following the trial. Each subject was also requested to complete a training record prior to the trial and keep a record of the daily symptoms of delayed onset muscle soreness (DOMS) both at rest (general pain) and during walking (daily living). Full blood counts (FBC), serum creatine kinase (CK), lactate dehydrogenase (LDH) and Cortisol concentrations were measured using standard haematological laboratory procedures and serum C-Reactive Protein (CRP) was determined by immunoturbidimetric assay. Sandwich ELISA's were used to determine myeloperoxidase (MPO) and plasma interleukin-6 (IL-6) concentrations. All results obtained were adjusted for changes in plasma volume as calculated from the red blood cell indices. Results: Mean ± SD characteristics of the gender-matched subjects in the experimental (TRS) and placebo-control (PLAC) groups did not differ significantly in terms of BMI, age, % body fat, FVC, FEVi, training age and status, foot strike pattern or peak running performance, maximal Heart Rate, VE, V02peak> RER, RPE during the maximal exercise test (p > 0.05). This indicated that the randomised pairs were well matched. The 90-minute downhill running protocol resulted in significant elevations in total circulating white blood cell count (WBC), neutrophil, CK, LDH, Cortisol, CPR, MPO and IL-6 concentrations (p < 0.001). When comparing the TRS and PLAC groups, mean ± SD total and differential WBC count, neutrophil count, CK, LDH, Cortisol, CPR, MPO and IL-6 concentrations did not differ (p > 0.05) over the 5 time points. At 24 PE, MPO concentrations were significantly higher in the TRS group than in the PLAC group (p = 0.03). The lower mean ± SD post-trial DOMS scores reported by the TRS group were not significantly different from those reported by the PLAC group (p > 0.05). Conclusion: Although the findings of this study did not identify differences in circulating CK, LDH, Cortisol, CPR and IL-6 concentrations between the TRS and PLAC groups, the elevated MPO concentration at 24 PE did provide preliminary novel evidence of enhanced activation of neutrophil oxidative burst activity following exercise-induced muscle damage which is hypothesized to accelerate the recovery process.
Physiological response to incremental stationary cycling using conventional, circular and variable-geared, elliptical Q-chain rings.
(2008) Jones, Andrew D.; Peters-Futre, Edith Margret.
Background: As variable-geared, elliptical Rotor Q-rings may improve pedal dynamics by reducing the effect of the "dead spot" in the pedaling action and altering the mechanical leverage, use of these chain rings is currently gaining popularity among competitive amateur and professional cyclists. There are, however, no randomized, controlled, published studies examining the physiological effect of using Rotor Q-rings vs. standard circular chain rings. In addition, no previous studies comparing circular and noncircular chain rings have included analysis of the markers of exercise induced muscle damage. Aim: This work was designed to compare physiological response to an incremental cycling protocol when using Rotor Q-rings (QR) with an eccentricity ratio of 1.10 and 74° default setting, to that obtained when normal, circular chain rings (NR) are used. Methods: Twelve trained amateur cyclists (age: 40.67 ± 7.53 years) performed two incremental tests to exhaustion on their own bicycles in a controlled laboratory environment. The subjects were randomized to QR and NR trials which took place seven days apart, within a cross-over design. The type of chain ring attached to the cycle (QR vs. NR) was blinded from the participant. After an eight-minute warm-up at 130 W, the power output was increased by 30 W on the minute. During each trial, heart rate, VE, V02 were measured continuously and RPE and blood lactate concentration were measured during the last 15 seconds of each workload. Ventilatory and blood lactate turn- points were determined from serial VE and blood lactate concentrations. Serum lactate dehydrogenase (LDH) concentration was measured before and immediately after each trial. A numerical pain rating scale was used to assess post exercise leg muscle and knee joint soreness 24hr post trial. Results: There was no statistically significant difference (p > 0.05) in mean peak power output (380 ± 29.0 W vs. 385 ± 31.8 W), mean power (194.9 ± 12.7 W vs. 197.2 ± 16.7 W), mean distance covered (9.02 ± 1.29 km vs. 8.89 ± 1.84 km) during the QR and NR trials, respectively. There were no statistically significant differences between trials in submaximal and maximal V02, VE or RPE, and ventilatory or lactate turnpoints (p > 0.05). Knee pain and leg muscle soreness as well as and increment in serum LDH levels did also not differ significantly following the two trials (p > 0.05). The difference in peak blood lactate concentrations (12.62 mmol. £"' ± 2.15 on QR vs. 13.84 mmol. £"' ± 1.68 on NR), however, reached borderline significance (p = 0.055). Conclusion: Despite the popularity of non-circular chain rings and the apparent mechanical advantage derived from their use, the findings of this study were unable to provide support for significant physiological advantages when using Rotor Q-rings with an eccentricity ratio of 1.10 and 74° default setting, during an incremental cycling test to exhaustion. While the borderline significance of the lower mean maximal blood lactate concentration following the Q-ring trial requires confirmation in a larger study, the possible roles of training, higher eccentricity ratios and different orientations of the crank to the chain ring in eliciting a physiological advantage, require further investigation.
An economic impact analysis of the Comrades Marathon on the city of Durban.
(2009) Maharajh, Ashok.; Coopoo, Yoganathan.
Sport has become a major industry as well as a key cultural preoccupation in contemporary society. Cities are increasingly using major sporting events and activities to re-image themselves, promote urban development and fund economic growth and regeneration. Major sport events are often recognised for their ability to generate significant economic benefits for the host destination. The major difference between this study and other economic impact studies is that the event is tracked over a two-year period. This afforded the author the opportunity to compare and note the variations in the data over the two years. Initially, the study purports to analyse the economic impact of the Comrades Marathon on the City of Durban. A secondary objective is to demonstrate the value of such a major sporting event to the regional and provincial governments as well as the formal and informal businesses in the city. Durban like other key cities in the world is and will increasingly be confronted by two main and related challenges. Firstly, there is need to successfully compete in a universal economy characterised by increased competition and globalization. Secondly, there is need to eliminate poverty and address issues of inequality and marginalization. Thus, the Comrades Marathon, as a major sporting event, can be seen as a primary driver to create jobs and contribute to competitiveness. As stated the research was conducted over two years viz. 2004 and 2005 thus representing an "up" and a "down" run. The questionnaire method and interviews were employed for this study and were administered to accommodate the alternate runs. The questionnaire requested data on the age, gender, occupations, income levels, spending patterns and the types of activities that the population found attractive. The population consisted of foreign runners and supporters, runners and supporters that reside in other provinces of South Africa, stall holders at the Comrades Expo that is normally held over three days prior to the race, representatives of the sponsors of the event and vendors. The sample was selected randomly from the population. Face-to-face interviews were conducted with representatives from the hotel industry in Durban, the Acting-Chief Executive Officer and committee members of the Comrades Marathon Association and the Marketing Managers/Public Relations Officers of three major shopping malls located in Durban. Turco, Swart, Bob and Moodley (2003) reported that the leverage ratio that is public sector input against private sector response indicated that the 2001 Comrades Marathon together with other major sporting events held in the city were successful and contributed significantly to the Durban economy. The leverage ratio is illustrative of the amount of money that was accrued to the private sector with every Rand spend by the public sector. Consideration was given to the total revenue generated by peoples' average spending at the events and the total amount accruing to the accommodation industry. Cognisance must be taken that the leverage ratio does not consider overall spending in Durban as well as other general multipliers such as revenue generated from transport, other financial transactions, product suppliers, guided tours, established businesses and informal traders. The findings showed that the leverage ratio for 2004 was computed to be 1:216.38 that is for every Rand spent by the public sector on the event R216.38 was generated by the private sector. In addition, the leverage ratio for 2005 was computed to be 1:434.49 that is for every Rand spend by the public sector on the event R434.49 was generated by the private sector. Thus, the expenditure was considerably higher in 2005 with an upsurge of R31 819 272 that is an increase of 33%. The fundamental idea behind the economic impact of sporting events is that it injects a significant increase in the demand of goods and services into the economy. This effect is not simply the direct effect of consumer spending but also the indirect effects caused by the stimulus to the economic activities induced by the direct effects.
The prevalence of obesity and related risk factors amongst nurses in a public health hospital in KwaZulu-Natal.
(2010) Kapitan, Meenal.; van Heerden, J.
Introduction: The prevalence of obesity in South Africa and throughout the world is increasing. Obesity is related to hypertension, atherosclerosis, diabetes, dyslipidemia and other sub-clinical conditions. Aim: To establish the prevalence of obesity and related risk factors among nurses in a public health hospital in KwaZulu-Natal. Methods: The design entailed a cross-sectional survey among 250 randomly selected nurses (22-64 years) working in King Edward Hospital (KZN). Obesity was measured using anthropometric and derived parameters of stature, body mass, body mass index (BMI) and waist to hip ratios (WHR). Related risks were determined using a screening questionnaire. Results: The mean body mass and BMI observed was 84.42 ± 17.49 kg and 32.60± 6.34 kg/m2, respectively with 76.10% of the sample being overweight or obese (64.80%; BMI~30). The mean waist circumference (93.01±12.73 cm) fell into the high risk category. A large proportion (30.4%) reported experiencing lower back pain. A significant crude odds ratio (OR) was found between obesity and the risk for lower back pain with an OR of 2.53 (CI 1.12 - 5.71). An increased but insignificant risk was observed in obese individuals for hypertension (OR 1.85: CI 0.63 - 5.40). Stressed individuals (PSS> 13) had an increased but insignificant risk for obesity (OR 1.78: CI 0.70 - 4.50) but a significantly increased risk for lower back pain (OR 8.59: CI 2.00-36.85; p:S0.05). Only 79 of the 250 nurses (31.6%) from our sample reported doing vigorous exercises on a regular basis and the nature of their exercise programs did not protect against the risk of obesity (OR 2.18: CI 1.03-4.60; p:S0.05). Discussion and Conclusion: A high prevalence of obesity and related risk factors among this population of nurses in a public hospital, and potentially in the nursing occupation at large, should be addressed within the context of employee wellbeing. The need for education on appropriate diet and exercise programming in order to prevent hypokinesis and associated diseases of lifestyle is evident. Key words: Nurses, Body Mass Index, Obesity, Low Back Pain, Hypertension, Stress, Hypokinesis
Acute stress and strain due to backpack loading among primary school pupils.
(2011) Abrahams, Sumaya.; Ellapen, Terry Jeremy.; Van Heerden, H. J.
Schoolbag carriage represents a considerable daily occupational load for children (Negrini et al., 1999). Whittfield et al., (2001) and Puckree et al., (2004) have reported that the carriage of heavy schoolbags is a suspected aetiological factor of the daily physical stress of school pupils. Methods: One hundred and eighty-seven pupils voluntarily participated in a controlled, descriptive, epidemiological retrospective study. Subjects’ biographical, epidemiological, exercise history and lifestyle information was gathered by a self-report questionnaire (adapted from Puckree et al., 2004). Subjects’ body mass, stature and mass of their schoolbags were measured using a Detecto stadiometer scale. Digital images, electromyographical muscular activity and a posture profile assessments were captured in the frontal and sagittal planes whilst the pupils were in the loaded (carrying a schoolbag) and the unloaded phases (not carrying schoolbags). These images were analyzed using biomechanical software, Dartfish. The study being retrospective in nature recorded the prevalence of schoolbag carriage musculoskeletal pain over the last 12 months. Descriptive statistical tests such as mean, mode, frequency, percentages and inferential chi-square statistical test (set at a probability of 0.05) were employed to analyze the data. Results: The result indicated that 78.99% of the cohort experience musculoskeletal pain due to schoolbag carriage (p<0.0001). The most prevalent anatomical sites of pain were the shoulders (37.04%), neck (20.37%), lumbar (11.73%) and thorax (10.49%) (p<0.0001). The mean mass of the schoolbag carried by the cohort was 5.45kg which was approximately 11.5% of their body mass. The predisposing factors of the musculoskeletal pain were the methods employed to carry the schoolbag (single strap (20.21%) versus double straps (76.6%), altered posture due to excessive schoolbag mass together with a reduced craniovertebral angle (p<0.05). Discussion & Conclusion: The excessive schoolbag mass carried by the pupils placed strain on the immature vertebral column of these pupils thus causing postural deviations which induced musculoskeletal pain and discomfort.
Five minute recordings of heart rate variability in physically active students : reliability and gender characteristics.
(2011) Sookan, Takshita.; McKune, Andrew James.
Introduction Heart rate variability (HRV) is regarded as a useful, non-invasive method for investigating the autonomic nervous system (ANS). Over the past decade there has been an increase in the number of HRV investigations in the disciplines of medical, sport and exercise science. Despite the extensive use of HRV in investigations of ANS functioning, there are questions relating to the reliability of the technique. Therefore, HRV reliability studies for different population groups have been advocated. Furthermore, research on gender differences in HRV is contradictory. This has resulted in the need to investigate gender characteristics in HRV. Objectives The objective of this study was to evaluate the reliability of short-term (5min) recordings of HRV, and to determine the association between HRV and gender. Methods Forty four physically active students (n= 21, age= 21.17 (1.55) males and n=23, age= 19.75 (1.76) females) participated in the study. Heart rate variability parameters were determined from five minute recording of interbeat intervals (IBI) using a Suunto t6 heart rate monitor (HRM). Testing was repeated over 4 consecutive days under the same conditions. The following HRV time and frequency domain measures were calculated using Kubios HRV Software Version 2.0: mean heart rate (HR), standard deviation of normal to normal intervals (SDNN), root mean square of successive differences (RMSSD), percentage of beats that changed more than 50 ms from the previous beat (pNN50), low frequency in normalized units (LFnu), high frequency in normalized units (HFnu) and low frequency to high frequency ratio in normalized units (LF/HFnu ratio). The data was summarized using routine descriptive statistics. Relative reliability was calculated using interclass correlation coefficients (ICC) (ICC of >0.80 indicated good to excellent reliability) and absolute reliability using typical error of measurement (TEM) and TEM as a percentage of the mean score (TEM%). This statistical measures were computed for days 2 vs 3 (REL 1), 3 vs 4 (REL 2). Day 1 was used as a familiarization day. An unpaired T-test was used to determine whether there were any differences between males and females for the above HRV parameters. Significance was set at p .0.05. Results The ICCs for both REL 1 and REL 2 indicated good to excellent (ICC >0.8) reliability for IBIs and pNN50 for the time domain results. In general, the time domain results had a higher relative reliability than the frequency domain results. Males had an overall lower relative reliability than females for frequency domain parameters. Absolute reliability for REL 2 showed a slightly lower TEM value as compared to REL 1.The largest gender differences in TEM were seen in the frequency domain parameters. Specifically, for males, the TEM was higher than females for the LF/HFnu ratio (REL 2: 116%), the HFnu (REL 1: 90%) and the LFnu (REL 1: 68%). Overall the TEM% was relatively high in most HRV parameters specifically for LF/HFnu (REL 1: 31.4% females and 48.1% males; REL 2: 29.7% females and 40.4% males). These findings indicate that males have decreased absolute reliability compared to females and that random error is greater in men for the frequency domain parameters. Gender differences illustrated significant differences for resting HR (16% higher in females (p < 0.0001)), IBIs (21% higher in females (p <0.0001)) and LF/HFnu ratio (41% higher in males (p = 0.003)). The findings indicate that females have higher total HRV. Conclusions Short term recordings of HRV over consecutive days using the Suunto t6 HRM and Kubios custom HRV software are reliable depending on the HRV parameter being analysed. Overall, the relative reliability results suggest that HRV using the Suunto t6 and Kubios is good. However, the absolute reliability results suggest low reliability. In particular, males demonstrated a poorer absolute reliability (high TEM and TEM%) than females, suggesting a larger day to day random error in males. Furthermore, specific HRV measures differed between males and females demonstrating that females have higher parasympathetic modulation compared to men. The overall higher HRV in females could explain the possible cardio-protective mechanism observed in premenopausal women. Key words: Heart rate variability, Parasympathetic, Reliability, Interbeat Intervals
Salivary biomarkers of mucosal immunity and sympathetic activation in children : effects of body composition, cardio-respiratory fitness and exercise.
(2012) Konkol, Kristen F.; McKune, Andrew James.
Worldwide, overweight/obesity and associated chronic diseases such as type 2 diabetes, have reached epidemic proportions. Statistics show that overweight/obesity and chronic disease is prevalent amongst adults and children in South Africa. In addition to chronic disease/non-communicable diseases, overweight/obesity has been shown to alter immune and sympathetic activation. There is limited information on immune function (mucosal) and sympathetic activation on children both internationally and nationally and in particular investigating these parameters using non-invasive methods such as salivary biomarkers. The aim of this thesis was to investigate the levels of salivary biomarkers of immune function and sympathetic activation in children and determine the association with overweight/obesity, cardiorespiratory fitness (CRF) and increased physical activity (PA). Methods This thesis is divided into six chapters. These include an introductory chapter (Chapter One), a review of the literature (Chapter Two) and then three chapters that are written in article format and that have each been submitted to accredited journals for publication. Chapter Three is a review article that discusses salivary biomarkers in children as they relate to exercise, PA and obesity. Chapter Four is a study that examined salivary biomarkers of mucosal immunity and sympathetic activation as predicted by age, body composition and cardiorespiratory variables in one hundred and thirty-two black South African children (age 10.05 ± 1.68y, 74 females, 58 males). Chapter Five is a study that investigated salivary biomarkers of mucosal immunity and sympathetic activation in response to 12 weeks of soccer training in thirty-four black male South African children (11 – 13y) from a youth football training academy. Chapter Six includes a summary of the research findings, conclusions and well as recommendations for future research. A review of the literature revealed that participation in regular moderate intensity PA or exercise appears to enhance mucosal immunity (increases salivary IgA (sIgA)) in preadolescent children. In contrast, poor fitness and inactivity as well as strenuous training appear to compromise the mucosal immune system thereby increasing the risk of upper respiratory tract infections (URTIs). Children reporting higher levels of body fat and with a greater BMI appear to have lower sIgA levels and a greater incidence of infections. The limited research examining salivary C-reactive protein (sCRP) suggests a strong association between poor cardio-respiratory fitness (CRF) and/or overweight/obesity and inflammatory status in children based on elevated sCRP levels. Research surrounding salivary alpha-amylase (sAA) indicates that exercise can result in a marked increase in sAA as seen by an increase sympathetic activity via increased adrenergic activity in the salivary glands. The limited research suggests exercise may also pose a high stress on young athletes as seen with an increase in sAA. Additionally it appears that BMI may be a strong predictor of stress-induced sAA increases in children. Greater hypothalamic pituitary adrenal (HPA) axis response, as seen by increases in salivary cortisol, appear to be influenced greatly by increases in obesity. Higher salivary cortisol secretions have been observed in obese versus lean children in response to exercise. School study: The outcomes of the one-way ANOVAs examining the differences by body mass index (BMI) categories showed there were significant differences in weight (F = 83.64, df = 2, 129, P < 0.0001), BMI (F = 193.36, df = 2, 129, P < 0.0001), waist-to-hip ratio (F = 193.36, df = 2, 129, P < 0.0001), body fat percentage (F = 336.98, df = 2, 129, P = 0.0001), SBP (F = 5.72, df = 2, 129, P = 0.0042), DBP (F = 291.76, df = 2, 129, P < 0.0001), VO2max (F = 521.00, df = 2, 129, P < 0.0001), sAA concentration (F = 17.05, df = 2, 129, P < 0.0001), sAA secretion rate (F = 15.15, df = 2, 129, P < 0.0001), sIgA concentration (F = 11.30, df = 2, 129, P < 0.0001), and sIgA secretion rate (F = 8.08, df = 2, 129, P = 0.0005), between children of different BMI categories. According to the CDC-BMI-for-age standards, the participants were grouped into the following CDC-BMI-for-age categories: normal weight (< 85th percentile), overweight (≥ 85th percentile to < 95th percentile), and obese (≥ 95th percentile) (Ogden and Flegal, 2010). Tukey’s post hoc analyses revealed that obese children had significantly (P < 0.01) higher weight, BMI, body fat percentage, DBP, SBP, sAA concentration and secretion rate, compared to overweight and normal weight children, as well as a significantly lower aerobic capacity (VO2max) than both normal (P < 0.001) weight and overweight (P < 0.05) children. In addition, sIgA concentration and secretion rate were significantly lower between normal weight and obese children (P < 0.01). Multiple linear regression revealed that BMI, DBP and VO2max predicted sAA. BMI (P = 0.04) and DBP (P = 0.04) were found to be independent predictors of sAA concentration. Age and BMI category predicted sIgA secretion rate. BMI category (P = 0.0006) was found to be an independent predictor of sIgA secretion rate. Soccer study: Significant differences after 12 weeks of soccer specific training were found to be significant between pre vs. post for BMI (P =0.034), waist-to-hip ratio (P = 0.046), age (P < 0.0001), height (P < 0.0001), body fat % (P < 0.0001) and LMM (P < 0.0001). Decreases in BMI, waist-to-hip ratio, body fat % and LMM were found while age and height increased throughout the 12 weeks. Significant differences were also found between sIgA secretion rate pre vs. post training (P =0.025) as increases in these values pre to post were observed. Conclusions The results from the studies on the school children and soccer players suggested that mucosal immune function and sympathetic activation appear to be affected by body composition, CRF and chronic exercise training. The main findings for the school study revealed that BMI, DBP and VO2 predict sAA and that age and BMI category predict sIgA. This study also found that obesity (based on BMI) has a major role to play and that obese children have elevated sAA, lowered sIgA, and poor CRF. The finding of an increase in sIgA secretion rate in the soccer study suggested that a structured 12 week exercise programme can elevate mucosal immune function in youth soccer players. The underlying mechanism responsible may be an exercise-induced increase in the transport of sIgA across the mucosal epithelium and/or enhanced production of IgA in the mucosa via mediating cytokines. The literature review demonstrated that PA and overweight/obesity may have an impact on salivary biomarkers of mucosal immunity and sympathetic activation in children, however further research with regards to optimal intensity, duration and modality need to be assessed in the pre-pubescent population.Physical activity, obesity, immunity, neuro-endocrine, children, salivary biomarkers, sympathetic activation.
Muscle damage and inflammation following a three-day trail run.
(2012) Denissen, Emmerentia C.; Peters-Futre, Edith Margret.
Introduction The physiological effects of single and multiday road running races have been studied extensively and include the occurrence of rhabdomyolysis, reflected by significantly increased urinary myoglobin (uMb), as well as increased concentrations of serum creatine phosphokinase (CPK), high sensitivity C-reactive protein (hsCRP), cortisol and cardiac troponin-T (cTnT), dehydration and compromised renal function. Furthermore, in hyperthermic athletes, a positive relationship has been noted between hyperthermia, muscle damage, dehydration and pacing. The physiological effects of a multiday trail run of similar duration to single day road races, however, are unknown. The side-effects of the use of statin medication for hypercholesterolaemia include muscle fatigue, cramping and increased muscle damage. These have been found to be aggravated in endurance athletes and it has been reported that females, especially when being medicated from a young age, are more susceptible to these side-effects. Objectives 1. To investigate the effect of a three-day trail run on systemic and urinary markers of muscle damage and inflammation in recreational runners and to establish the association of dehydration and hyperthermia with these markers. 2. To observe the effect of the three day trail run on systemic and urinary markers of muscle damage and inflammation on an additional hypercholesterolaemic female athlete using statin medication in combination with a lipid uptake inhibitor. Method Firstly, an observational cohort study was conducted on 19 recreational male (n=6) and female (n=13) athletes during a 95km trail run over three days. Pre-and post-stage and 24 and 72 h post-race concentrations of serum CPK, hsCRP, cortisol, cTnT, and osmolality (sOsm) as well as uMb, changes in body mass, delayed onset muscle soreness (DOMS) and thigh circumference (TC) were measured. Continuous recordings of heart rate (HR) and intestinal temperature (Tintest ) were made throughout each stage. In addition, a case report is included on one trained female endurance athlete currently being treated for familial hypercholesterolaemia with 20 mg Aspavor and 10 mg Ezetrol daily and not included in the above cohort, to investigate the degree of muscle damage and inflammation she experienced as a result of participation in the three-day event. Results: Heart rate ranged between 77 and 83% age-predicted-maximum (APmax) and Tintest between 36.1 and 40.2 ºC during the three stages. Significant rises in mean serum CPK, hsCRP, sOsm and blood neutrophil count reached peak concentrations of 1 488U/L, 8.91mg/l, 298mosm/L and 10.21 10^9/L (p≤0.001), respectively. No evidence of elevations in uMb and cTnT were detected. The stage-induced increments in DOMS correlated positively with CPK, r=0.71; 95% CI [0.62, 0.78]. TC decreased significantly post S1post and S2post (p≤0.05) and a maximum mean body mass loss of 3.09% (±1.04%) occurred during S2. There was no significant difference between nonsteroidal anti-inflammatory drug (NSAID) users and non-users in terms of serum CPK, hsCRP, cortisol, post race DOMS scores, running times, TC or sOsm (p>0.05). The post-pre change in sOsm during each stage correlated inversely with the changes in % body mass, r = -0.36, 95% CI [-0.57,-0.094] and the pooled data examining the relationship between the change of sOsm and change in serum CPK for the three stages (n=57), revealed an insignificant positive correlation (r= 0.034, 95% CI [-0.228, 0.291]. The maximum Tintest ranged between 38.3 º C and 40.2 º C and only exceeded 40º C in two of the 12 athletes monitored. The relationship between the change in Tintest and serum CPK was insignificant (p>0.05) for the 11 individuals from whom complete sets of data were available (r= 0.24, 95% CI [-0.42, 0.734]. In the hypercholesterolaemic athlete, the maximum serum CPK (665U/L), hsCRP (1.9mg/Ll) and cortisol (845nmol/L) concentrations corresponded with undetected uMb despite a maximum body mass loss of 4.5% Conclusion: Three consecutive days of 95km trail running resulted in low markers of muscle damage and inflammation, when compared to results obtained in previous single day road races of similar duration despite the maintenance of a heart rate above 77% APmax, Tintest rising above 39o C and mean body mass decrement of >2.0%. The unchanged concentrations of serum cTnT and uMb confirmed the low values of the markers of muscle damage and inflammation. An insignificant positive correlation between muscle damage and dehydration was noted. Furthermore the daily use of 0.4 mg/kg Atorvastatin in combination with 10mg Ezetrol did not result in the subject experiencing subjective myalgia, cramps, fatigue or increased markers of muscle damage following her participation in the trail run.
Association between physical fitness and job performance in South African fire-fighters.
(2012) Schmidt, Carl.; McKune, Andrew James.
Aim. Accurate correlations between a wide range of physical fitness measures and occupational demands are needed in order to identify specific fitness tests and training needs for firefighters. Methods. Forty-eight experienced, professional firefighters (29 ± 7.24 yrs) participated in fitness and job performance testing sessions each spaced a week apart. Analysis was performed using Pearson moment correlation coefficients and multiple linear regression with alpha set at p≤.05. Results. Significant correlations (p≤.01) were found between a job performance task (Revised Grinder) and the following: lean muscle mass (r = -.69), overall fitness (r = -.62), height (r = -.62), strength endurance: deadlift (r = -.54), bent-over row (r = -.51), bench press (r = -.51), shoulder press (r = -.46); maximal strength: hand grip strength (r = -.57), bench press (r = -.51), anaerobic capacity: 400m (r = .50), and aerobic capacity: multistage shuttle run (r = -.46). Multiple linear regression determined that lean muscle mass and aerobic capacity account for 82% of the variation in the job performance task. Conclusion. It is apparent that firefighting taxes virtually all aspects of physical fitness. This data can help the exercise specialist choose appropriate tests and prescribe specific fitness programmes for firefighters. Traditional firefighter exercise programmes focusing mainly on cardiovascular fitness should be replaced with physical conditioning programmes that address all components of fitness. Cardiovascular fitness testing should include the performance of job-related tasks to improve test validity.
Respiratory tract symptoms in multi-day trail runners - a focus on allergy.
(2012) De Waard, Anton Hans.; Peters-Futre, Edith Margret.
Introduction: Respiratory tract symptoms (RTS), common in athletes during heavy training and after events, result in impaired readiness for events and race times. Since the 1980’s exercise immunologists have investigated the aetiological factors surrounding the development of exercise induced RTS in order to develop effective preventative strategies. A number of theories have been put forward and explored, such as increased susceptibility to infection, ‘run-away’ inflammatory response and reactivation of prior viral infection. It has been suggested that the mechanisms producing exercise induced inflammation could potentiate allergic responses in sensitized individuals and recently allergic response has been proposed as a potential contributor to exercise induced RTS. Certainly allergic reactions can produce a range of respiratory symptoms; however the relationship between allergic sensitization, allergic reaction and the incidence of post-exercise RTS has not been well defined. Objectives: The primary objective of this study was to document the incidence of RTS for two weeks before and two weeks after a three-day trail run and relate these to the general systemic and salivary immunological profile as well as atopic status of the participants. The secondary objective was to validate the use of the Phadiatop® assay as a predictor of allergy-associated post-race RTS in trail runners. Study Design and Methods: The study formed part of a larger, descriptive field study examining the physiological responses of trail runners during the Three Cranes Challenge, a multi-day 95 km event divided into three stages, in Karkloof, KwaZulu-Natal. Outcome measures examined included self- reported RTS over a 31 day period (pre, during and post race), as well as pre-race Phadiatop® status, salivary IgA (sIgA) concentrations and changes in concentrations of serum IgE (sIgE), cortisol, high sensitivity C-Reactive Protein (hs-CRP) and differential leukocyte counts. The haematological and salivary parameters were obtained at 8 time points before, during and after the event. A convenience sample of 22 individuals was used and two separate analyses were conducted on the data. The inclusion criteria of the first analysis were met by 14 participants. In this analysis, the incidence of RTS was related to each participant’s general immunological profile. Sixteen of the subjects met the inclusion criteria for the second analysis, in which their Phadiatop® status was related to their sIgE and blood eosinophil and basophil concentrations in order to establish the validity of the Phadiatop® assay in predicting the development of allergy–associated postexercise RTS in trail runners. Results: In the first analysis, 78.6 % (n=11) of subjects met the criteria for positive diagnosis of upper respiratory symptoms (URS) during the two week post-race period. In four subjects (36.4 %), URS appeared to be of inflammatory origin, but these were not linked to systemic markers of an allergic response. Of the URS positive subjects, six (54.5 %) presented with markers of infection, three (27.3 %) with markers of a de novo infection and three (27.3%) with a profile suggestive of reactivation of previous infection. Of those presenting with markers of infection 66.7 % (n=4) had concomitantly elevated levels of IgE suggestive of allergic response. There was, however, no evidence of isolated allergic reaction independent of other causes amongst the symptomatic subjects. In the second analysis, 75% (n=12) of runners presented with post-race RTS and seven of these were Phadiatop® positive. In four of the Phadiatop® positive RTS subjects, symptoms appeared to be of allergic origin. Although total IgE concentrations were significantly higher (p< 0.01) in Phadiatop® positive group, there was no significant difference between the eosinophil and basophil concentrations or post-race RTS of the positive and negative groups (p>0.05). Of the four subjects who did not develop RTS, three were Phadiatop® positive. Conclusion: Respiratory tract symptoms in trail runners have a multi-factorial aetiology. A link between concurrent markers of an allergic response and infection is common in symptomatic trail runners. The Phadiatop® assay does not accurately predict the incidence of allergic postexercise RTS in trail runners.
The effects of music tempo on performance, psychological and physiological variables during 20 km cycling in well-trained cyclists.
(2013) Dyer, Barry.; McKune, Andrew James.
Introduction Music is commonly used to accompany exercise and has been viewed as a type of legal performance enhancing drug due to its beneficial effects such as reduced RPE, increased work output, enhanced mood, enhanced motor skill acquisition, and increased performance during a variety of exercise tasks. Despite the fact that athletes report using music before, during and after training to increase performance and self-regulate mood, the majority of evidence available has been based on untrained, non-athletic populations. This highlights the need for further research into the effects of music on well-trained individuals engaging in exercise. Objectives The purpose of this study was to investigate the effects of different music tempi on performance, psychological and physiological responses of well-trained, experienced cyclists to time trial cycling. Methods Ten male road cyclists (age:35yrs ± 7, VO2 peak: 5.6 L/min ± 0.4; sum of 7 skinfolds: 58 ± 9.4) performed four 20km time-trials on a Computrainer™ Pro 3D electromagnetically braked indoor cycle trainer over a period of four weeks. The time-trials were spaced a week apart. The music conditions for each trial were randomised between fast-tempo (140 bpm), medium-tempo (120 bpm), slow-tempo (100 bpm), and no-music. Measures recorded during the time-trials included (1) physiological: heart rate, oxygen consumption, breathing frequency, respiratory exchange ratio, (2) psychological: mood states (Profile of Mood States (POMS) pre and post time-trial), (3) Performance: peak and average power output, time to completion, pedal cadence and (4) rating of perceived exertion. Averaged data were compared using one-way analysis of variance. Data for heart rate, oxygen consumption, breathing frequency, RPE, cadence and power output were also collected at three minute intervals during each trial. These were compared using two factor (time x condition) repeated measures analysis of variance. For all data sets, where a significant difference was observed, a Bonferroni post-hoc test was used to determine specific differences. Significance was set at P < 0.05. Results Results revealed no significant changes in physiological variables or performance variables. Total mood disturbance and tension as measured by the POMS were increased significantly in response to the fast-tempo trial. Conclusion Fast tempo music is often perceived as highly motivational and results in increased arousal in the listener. It is likely that prolonged exposure to arousing stimuli such as fast tempo music in conjunction with the intense sensations associated with time-trial exercise could have led to the disturbances in mood state observed during the fast-tempo music trial.

Browse

Browsing Masters Degrees (Biokinetics, Exercise and Leisure Sciences) by Issue Date