Effect of Submaximal Warm-up Exercise on Exercise-induced Asthma in African School Children.

BACKGROUND: Regular physical activity has long been regarded as an important component of a healthy lifestyle. Exercise-induced asthma (EIA) is one of the major problems interfering with the performance of exercise. A warm-up exercise programme has been cited as a non-pharmacologic means of reducing EIA, but its effect has not been fully elucidated. OBJECTIVE: The aims of this study were to determine the prevalence of unrecognized EIA in Pretoria primary school children, determine the effect of a warm-up exercise programme on EIA and to establish the relationship between history of allergy, family history of asthma and EIA. METHODS: A random sample of 640 school children was selected. The study was divided into three phases. In phase one, a descriptive cross-sectional study was done using the standardized European Community Respiratory Health Survey (ECRHS) questionnaire. In phase two, non-asthmatic participants that returned a completed questionnaire were included in the field study. Pre-test and post-test experimental designs were used, where peak expiratory flow rate (PEFR) was measured at baseline and within ten minutes after exercise. A total of 340 subjects completed the Free Running Asthma Screening Test (FRAST); EIA was defined as a decrease in baseline PEFR ≥ 10% after exercise and 75 children (22%) had EIA. In phase three, 29 of the 75 subjects participated in the warm-up programme which was performed in the laboratory and subjects acted as their own controls. Predefined protocols for the study were followed. RESULTS: Seventy-five (22%) of the 340 participants had EIA. The mean age, height and weight were 10.51 years, 139.26 cm and 33.45 kg, respectively. Exercise-induced asthma symptoms were cough (25%), chest pain (16%), wheeze (12%) and chest tightness (12%). The history of allergy was 75%, family history of allergy 40% and positive history of allergy when near animals, feathers or in dusty areas 38%. Wheezing during or after exercise, wheezing when near animals, feathers or in dusty areas and chest pain was significant (p < 0.05). The mean PEFR after exercise without warm-up was 4.43 L/min. The mean PEFR after exercise (warm-up) was 4.98. The mean percentage change in PEFR between exercise without warm-up and exercise with warm-up was 14.83%. The paired t-test showed a significant difference between PEFR with warm-up and PEFR without warm-up (p < 0.05). CONCLUSION: There was a high prevalence of EIA among study participants. Exercise-induced asthma symptoms were significant for wheezing and chest pain. Exercise after warm-up was significant in reducing EIA. This study reports the effect of warm-up exercise on EIA and highlights the need to screen school children for EIA.

Ethylene vinyl alcohol: a review of barrier properties for packaging shelf stable foods.

Ethylene vinyl alcohol (EVOH) is one of the best known flexible thermoplastic oxygen barrier materials in use today. It is especially important for refrigerated and shelf-stable foods where oxygen deteriorates the quality of packaged products and reduces their shelf life. EVOH accounts for a majority of thermoplastic barrier materials used for rigid or semi-rigid retortable food containers. However. it is of limited use in flexible packages or lid films for rigid trays used for packaging thermally processed shelf-stable low acid foods due to its moisture sensitivity. Nevertheless, current use of other oxygen barrier materials such as polyvinylidene chloride and aluminum foil creates environmental concerns. Innovations in food processing technologies provide opportunities for increased use of EVOH in food packaging. The aim of this review is to give an overview of research on the oxygen barrier properties of EVOH from the perspective of structure-barrier property relationships and the consequences of food processing conditions.

Knowledge of students attending a high school in Pretoria, South Africa, on diet, nutrition and exercise / Conocimientos de los estudiantes que asisten a una escuela secundaria de Pretoria, África del Sur, acerca de las dietas, la nutrición y los ejercicios

OBJECTIVE: The objective of this study was to ascertain the knowledge of students on the composition of a healthy diet, daily nutritional requirements and the importance of regular exercise. METHOD: A cross-sectional survey using a self-administered questionnaire with closed and open-ended questions to assess students 'knowledge on diet, nutrition and exercise was conducted. The study group were students of Tswaing High School in Pretoria, South Africa, who were in attendance on a particular day when the study was conducted and who consented to participate in the study. Only 500 students of the school participated in the study. RESULTS: Results showed that 77% of the students do not have adequate knowledge on diet, nutrition and exercise while 23% of the students showed satisfactory knowledge. Approximately 26% and 16% of the students reported that they participated in rigorous and moderate exercise respectively. The study also showed that the majority ofthe students were however not engaged in physical activities. CONCLUSION: Students at Tswaing High School do not have adequate knowledge on nutrition, diet and exercise. Their views on what exercise entails were found not to be satisfactory. Programmes/ infor­mation or seminars that could assist to inform students on the importance ofdiet and exercise are therefore suggested.

OBJETIVO: El objetivo de este estudio fue determinar el conocimiento de los estudiantes sobre la composición de una dieta saludable, los requisitos nutritivos diarios, y la importancia de realizar ejercicios deforma regular. MÉTODO: Se realizó un estudio transversal usando una encuesta auto-administrada con preguntas cerradas y abiertas, a fin de evaluar el conocimiento de los estudiantes sobre las dietas, la nutrición y los ejercicios. El grupo del estudio estuvo formado por estudiantes de la Escuela Secundaria Tswaing en Pretoria, África del Sur, que estaban presentes el día cuando se llevó a cabo el estudio, y estuvieron de acuerdo en participar en dicho estudio. Sólo 500 estudiantes de la escuela participaron en el estudio. RESULTADOS: Los resultados mostraron que el 77% de los estudiantes no tienen conocimientos adecuados sobre la dieta, la nutrición y los ejercicios, mientras que el 23% de los estudiantes mostraron conocimientos satisfactorios. Aproximadamente el 26% y el 16% de los estudiantes reportaron haber participado en ejercicios rigurosos y moderados respectivamente. Sin embargo, el estudio también mostró que la mayoría de los estudiantes no participaban en actividades físicas. CONCLUSIÓN: Los estudiantes en la escuela secundaria de Tswaing no tienen conocimientos adecuados sobre nutrición, dieta y ejercicios. Se halló que sus opiniones sobre lo que los ejercicios implican, no eran satisfactorias. Por lo tanto, se sugieren programas de información o seminarios que puedan ayudar a informar a los estudiantes acerca de la importancia de la dieta y los ejercicios.

Knowledge of students attending a high school in Pretoria, South Africa, on diet, nutrition and exercise.

OBJECTIVE: The objective of this study was to ascertain the knowledge of students on the composition of a healthy diet, daily nutritional requirements and the importance of regular exercise. METHOD: A cross-sectional survey using a self-administered questionnaire with closed and open-ended questions to assess students 'knowledge on diet, nutrition and exercise was conducted. The study group were students of Tswaing High School in Pretoria, South Africa, who were in attendance on a particular day when the study was conducted and who consented to participate in the study Only 500 students of the school participated in the study RESULTS: Results showed that 77% of the students do not have adequate knowledge on diet, nutrition and exercise while 23% of the students showed satisfactory knowledge. Approximately 26% and 16% of the students reported that they participated in rigorous and moderate exercise respectively The study also showed that the majority of the students were however not engaged in physical activities. CONCLUSION: Students at Tswaing High School do not have adequate knowledge on nutrition, diet and exercise. Their views on what exercise entails were found not to be satisfactory. Programmes/ information or seminars that could assist to inform students on the importance of diet and exercise are therefore suggested.

Chemical composition of Mopane worm sampled at three sites in Botswana and subjected to different processing.

Effects of site and degutting on chemical composition of mopane worm were investigated. Samples were cooked for 30 min in either brine or in plain water. Samples from Moreomabele were high in acid detergent fibre (ADF) (P < 0.05) and acid detergent insoluble nitrogen (ADIN) (P < 0.01) while samples from Sefophe had least ADF and ADIN concentrations. In vitro true dry matter digestibility (IVTDMD) tended (P = 0.06) to be high in samples from Maunatlala than those from Moreomabele and Sefophe. No site difference (P > 0.05) was observed on the rest of the variables. Degutted samples had high crude protein (CP), ADF and IVTDMD (P < 0.05) but lower (P < 0.001) concentrations of ash, acid detergent lignin (ADL) and condensed tannins. Acid detergent insoluble nitrogen was significantly higher (P < 0.001) in degutted than whole samples. Salting did not (P > 0.05) change concentrations of all but ADF which tended (P = 0.09) to be high in salted samples. Samples which were degutted and salted had higher (P < 0.01) ADF and ADIN than degutted and salted or those left whole and salted or left unsalted. Leaving samples as whole diluted the concentration of CP but increased the fibre components and condensed tannins content. However, mopane worm destined for livestock feeding may be left whole and salt added.