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.