Validity of 20 Meter Multi-stage Shuttle Run Test For Estimation of Maximum Oxygen Uptake in female University Students.

Indirect protocols for determination of cardiorespiratory fitness in terms of VO2max have been developed to avoid the complicated experimental protocol of direct VO2max estimation especially in clinical setting. 20-meter multi stage shuttle run test (SRT) is one of such indirect protocols developed in Western population. Eighty eight (88) sedentary young healthy female university students (Age 22.8±1.79 years, Body height 159.0±4.28 cm and Body mass 52.47±4.17 kg) of same socio-economic background were recruited in the study by simple random sampling from University of Calcutta, Kolkata, India to validate the applicability of SRT in the studied population. They were randomly separated into “study group” (N=58) on which the existing experimental protocol of SRT was tested and “confirmatory group” (N=30) on which the modified equations were validated. VO2max of each participant was determined by direct procedure and indirect SRT method. The difference between the mean values of directly measured VO2max and indirectly predicted VO2max (PVO2max) in the “study group” was statistically significant (P<0.001). Limit of agreement analysis revealed poor confidence level for application of current method of SRT in the studied population. However, VO2max was significantly correlated with age (r = 0.71, P<0.001), body mass (r = 0.58, P<0.001), body height (r = 0.55, P<0.001), speed (r = 0.92, P<0.001) and PVO2max (r = 0.89, P<0.001). Modified norms in the form of simple and multiple regression equations were applied in the Confirmatory Group. Results suggested a good agreement of the modified equations of SRT in this population with substantially small SEE. Hence, the currently proposed modified norms are recommended to predict VO2max in the studied population.

Pulmonary function studies in young healthy Malaysians of Kelantan, Malaysia.

Background & objectives: Pulmonary function tests have been evolved as clinical tools in diagnosis, management and follow up of respiratory diseases as it provides objective information about the status of an individual's respiratory system. The present study was aimed to evaluate pulmonary function among the male and female young Kelantanese Malaysians of Kota Bharu, Malaysia, and to compare the data with other populations. Methods: A total of 128 (64 males, 64 females) non-smoking healthy young subjects were randomly sampled for the study from the Kelantanese students’ population of the University Sains Malaysia, Kota Bharu Campus, Kelantan, Malaysia. The study population (20-25 yr age group) had similar socio-economic background. Each subject filled up the ATS (1978) questionnaire to record their personal demographic data, health status and consent to participate in the study. Subjects with any history of pulmonary diseases were excluded from the study. Results: The pulmonary function measurements exhibited significantly higher values among males than the females. FEV1% did not show any significant inter-group variation probably because the parameter expresses FEV1 as a percentage of FVC. FVC and FEV1 exhibited significant correlations with body height and body mass among males whereas in the females exhibited significant correlation with body mass, body weight and also with age. FEV1% exhibited significant correlation with body height and body mass among males and with body height in females. FEF25-75% did not show any significant correlation except with body height among females. However, PEFR exhibited significant positive correlation with all the physical parameters except with age among the females. On the basis of the existence of significant correlation between different physical parameters and pulmonary function variables, simple and multiple regression norms have been computed. Interpretation & conclusions: From the present investigation it can be concluded that Kelantanese Malaysian youths have normal range of pulmonary function in both the sexes and the computed regression norms may be used to predict the pulmonary function values in the studied population.

Validity of 20 meter multi-stage shuttle run test for estimation of maximum oxygen uptake in male university students.

Direct estimation of cardiorespiratory fitness in terms of VO2max is restricted within well equipped laboratory. Eighty four (84) sedentary male university students (Age 22.77±1.73 years, Body height 167.73±4.07 cm and Body mass 58.25±4.02 kg) of same socio-economic background were recruited from students of University of Calcutta, Kolkata, India to validate the applicability of 20 meter shuttle run test (SRT) for indirect estimation of VO2max in young male sedentary university students of Kolkata, India. They were further asigned to “study group” (N=54) on which the existing experimental protocol of SRT was tested and “confirmatory group” (N=30) on which the modified equations were validated. VO2max of each participant was determined by direct procedure and indirect SRT method with a gap of four days in between the tests. The difference between the mean values of directly measured VO2max and indirectly predicted VO2max (PVO2max) in the “study group” was statistically significant (P<0.001). Limit of agreement analysis revealed poor confidence level for application of current method of SRT in the studied population. VO2max was significantly correlated with age (r=0.70, P<0.001), body mass (r=0.64, P<0.001), body height (r=0.58, P<0.001), speed (r=0.94, P<0.001) and PVO2max (r=0.89, P<0.001). Modified norms in the form of simple and multiple regression equations have been computed. Our results suggest that SRT in its original form cannot be applied in the young males of Kolkata, India, due to its poor agreement with the direct method but is applicable with the modified equations. The SEE of these currently proposed norms arc substantially small enough to recommend the modified equations in the studied population to evaluate VO2max.

Effects of acute supplementation of Panax ginseng on endurance running in a hot & humid environment.

Background & objectives: Athletes in Malaysia need to perform in a hot and humid environment due to the climatic nature of the country. c0 hronic supplementation of Panax ginseng (PG) (a deciduous perennial plant belonging to the Araliaceae family) enhances physical performance. As the ergogenic effect of acute supplementation of PG on endurance performance has not been explored in the Malaysian population especially in a hot and humid condition this study was taken up. Methods: Nine heat adapted recreational runners (age : 25.4 ± 6.9 yr, body mass : 57.6 ± 8.4 kg; body height : 168.3 ± 7.6 cm) were recruited in this placebo-controlled double-blind randomized study. Subjects ingested 200 mg of PG one hour before the exercise test on treadmill at 70 per cent of their VO2max in a laboratory environment of 31 °C and 70 per cent relative humidity. They drank 3 ml/kg body weight of cool water every 20 min during the exercise to prevent adverse effects of dehydration. Blood samples were drawn every 20 min for the analysis of glucose, lactate, insulin and free fatty acids. Oxygen uptake was determined every 20 min while heart rate, body and skin temperatures, and ratings of perceived exertion (RPE) were recorded every 10 min during the trials. Results: Endurance running time to exhaustion did not differ between PG and placebo trials. Heart rate, skin temperature, core body temperature, oxygen uptake, RPE, plasma insulin, glucose, free fatty acid and lactate levels during the endurance exercise did not show any significant differences between the trials. Interpretation & conclusions: We conclude that acute supplementation of 200 mg of PG did not affect the endurance running performance of the heat-adapted male recreational runners in the heat.

Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot & humid climate.

Background & objectives: Athletes in Malaysia need to perform in a hot and humid climate. Chronic supplementation of caffeine on endurance performance have been studied extensively in different populations. However, concurrent research on the effects of acute supplementation of caffeine on cardiorespiratory responses during endurance exercise in the Malaysian context especially in a hot and humid environment is unavailable. Methods: Nine heat adapted recreational Malaysian male runners (aged: 25.4 + 6.9 yr) who were nonusers of caffeine (23.7 + 12.6 mg per day) were recruited in this placebo - controlled double - blind randomized study. Caffeine (5 mg per kg of body weight) or placebo was ingested in the form of a capsule one hour prior to the running exercise trial at 70 per cent of VO2max on a motorised treadmill in a heat-controlled laboratory (31oC, 70% relative humidity). Subjects drank 3 ml of cool water per kg of body weight every 20 min during the running trials to avoid the adverse effects of dehydration. Heart rate, core body temperature and rate of perceived exertion (RPE) were recorded at intervals of 10 min, while oxygen consumption was measured at intervals of 20 min. Results: Running time to exhaustion was significantly (P<0.05) higher in the caffeine trial compared to the placebo trial. Heart rate, core body temperature, oxygen uptake and RPE did not show any significant variation between the trials but it increased significantly during exercise from their respective resting values in both trials (P< 0.001). Interpretation & conclusion: Our study showed that ingestion of 5 mg of caffeine per kg of body weight improved the endurance running performance but did not impose any significant effect on other individual cardiorespiratory parameters of heat-acclimated recreational runners in hot and humid conditions.

Prediction of maximal oxygen consumption from body mass, height and body surface area in young sedentary subjects.

The study was aimed to establish prediction norms for maximal oxygen uptake (VO2max) from age, body mass and body surface area (BSA) in young sedentary subjects of Kolkata, India. Students of 20-24 years (male = 40 and female = 40) were recruited by simple random sampling from University of Calcutta, Kolkata. Thirty participants from each sex were further randomly alloted to the "study group" and rest 10 participants to the "confirmatory group". Physical parameters were measured and VO2max determination comprised of incremental bi-cycle exercise followed by expired gas analysis in Scholander micro-gas analyzer. Significant (P<0.001) correlation of VO2max existed with age, body mass, body height and BSA. Prediction of VO2max in the confirmatory groups using the norms obtained from different physical parameters depicted insignificant variation from the directly measured value of VO2max. Among these equations VO2max prediction from BSA was considered as the most valid one because of its highest correlation coefficient with VO2max in both the sexes. Multiple regression equation for prediction of VO2max from body mass and body height was also computed. The equation established from BSA is recommended as the most reliable and valid to predict VO2max in the young sedentary subjects of Kolkata, India; and multiple regression equations are also recommended for cross-checking the value.

Cardiorespiratory fitness of obese boys.

Childhood obesity is increasing worldwide and may be linked to coronary heart diseases that appear later in life but its risk related behaviour patterns are evident during childhood and adolescence. The present study aimed to evaluate the cardiorespiratory fitness in terms of maximum oxygen uptake (VO2max) in obese boys of West Bengal, India. Obese boys (N = 49) in the age range of 10-16 years were separated from their non-obese counterparts (N = 70) according to international age-wise cut off points of body mass index (BMI) and VO2max was evaluated by Queen's College Step Test (QCT). Lean body mass (LBM) was measured by skinfold method. Absolute VO2max was significantly higher (P<0.001) among obese boys because of higher values of body mass and LBM, which in turn exhibited significant correlation (r = 0.82 and r = 0.93, respectively; P<0.001) with VO2max. But VO2max per kg of body mass was significantly higher among non-obese boys but the VO2max per unit of body surface area was significantly higher (P<0.001) in obese group. VO2max is largely dependent on body mass and LBM whereas excessive fat mass imposes unfavourable burden on cardiac function and oxygen uptake by working muscles. This indicates that reduced oxygen utilization by adipose tissue during exercise reduces the overall VO2max.

Validity of Queen's College Step Test for estimation of maximum oxygen uptake in female students.

BACKGROUND AND OBJECTIVES: Maximum oxygen uptake (VO(2) max) is internationally accepted parameter to evaluate the cardiorespiratory fitness. But determination of VO(2)max is restricted within well equipped laboratory because of its exhausting, hazardous and complicated experimental protocol. Various attempts have been made to enumerate indirect and easy protocols for prediction of VO(2)max but such record is unavailable in Indian women. The present study was conducted to validate the applicability of Queen's College Step Test (QCT) for indirectly estimating the maximum oxygen uptake in female sedentary university students. METHODS: Forty sedentary female university students of same socio-economic background were recruited by simple random sampling from University of Calcutta, Kolkata. VO(2)max of each participant was determined by direct procedure and indirect QCT method with a gap of four days in between the tests. Direct estimation of VO(2)max comprised incremental bicycle exercise followed by expired gas analysis by Scholander micro-gas analyzer whereas VO(2)max was indirectly predicted by standard protocol of QCT. RESULTS: The difference between the mean VO(2)max values directly measured and indirectly predicted (PVO(2)max) was statistically significant (P<0.001). Limit of agreement analysis revealed poor confidence level for application of current method of QCT in the studied population. VO(2)max value exhibited significant correlation (r = -0.83, P<0.001) with QCT pulse rate. For precise and reliable estimation of VO(2)max in the studied population a new equation was computed. INTERPRETATION AND CONCLUSION: Our results suggest that QCT in its original form cannot be applied due to its poor agreement with the direct method but can be applied with the modified equation in this population to evaluate maximum oxygen uptake, especially when large numbers of participants are to be tested in absence of a well equipped laboratory.