Maximum oxygen uptake or VO₂max has been internationally accepted as the best parameter to evaluate cardiorespiratory fitness. Direct measurement of cardiorespiratory fitness in terms of VO₂max is restricted within the well equipped laboratory because of its exhausting and difficult experimental protocol (Fox, 1973). Among various indirect protocols (Fox, 1973; Das and Bhattacharya, 1995; Kline et al., 1987; Siconolfi et al., 1982; Mcardle et al., 1972) the Queen’s College step test or QCT is the simplest one and has already been established as the best indirect method to evaluate cardiorespiratory fitness in young Indian individuals (Chatterjee et al., 2006).

There is dearth of data on VO₂max among sedentary college students of Uttar Pradesh, India. The present study was therefore conducted to:

(i)

Evaluate VO₂max in college students of Uttar Pradesh, India.

Selection of Participants

Male (N=75) and female (N=75) healthy sedentary students from the middle class socioeconomic background, having age range of 19 to 24 years were recruited for the study on the basis of random sampling from the Institute of Dental Sciences, Bareilly, Uttar Pradesh, India. The experimental protocol was fully explained to participants to allay their apprehension and ensure maximum co-operation. They had a light breakfast 2–3 hours before the test and refrained from any energetic physical activity for that period. The participants had no history of any major disease and did not follow any physical conditioning program, apart from some recreational sports. All the participants were non-smokers. Necessary permission was taken from the ethical committee to conduct the study.

Age of each participant was calculated from the date of birth as recorded in their school certificate. Body height and body mass were measured with standard instrument with an accuracy of + 0.5 cm in case of body height and + 0.25 kg in case of body mass. The body surface area was calculated from the equation of DuBois and DuBois (1916) which is as follows:

BSA (m²) = (Body Height)^0.725 x (Body Mass)^0.425 x 0.007184

Evaluation of VO₂max by QCT

The step test was performed on a stool of 16.25 inches (41.3 cm) height for a total duration of 3 minutes at the rate of 24 cycles per minute, which was set by a metronome. After completion of the exercise, the subject was asked to remain standing and the carotid pulse rate was measured from 5–20 seconds of the recovery period. This 15 second pulse rate was converted into beats per minute and the following equations were used to predict the maximum oxygen uptake capacity (Chatterjee et al., 2004; Chatterjee et al., 2005):

In Males:

VO₂max (ml/kg/min) = 55.23 - (0.09 x pulse rate in beats/min)

In Females:

VO₂max (ml/kg/min) = 54.12 - (0.13 x pulse rate in beats/min)

The whole experiment was performed at a laboratory temperature varying from 27–29°C and with the relative humidity ranging between 75% and 83%.

Means and standard errors of age, body height, body mass, BSA and VO₂max of the male and female participants are presented in table 1. Though age did not show any inter-group variation, but the values of all other parameters are significantly higher among males than the female students.

Table 2 shows the correlation coefficients of VO₂max with different physical parameters. All the physical parameters are significantly (P<0.001) correlated with VO₂max in both the sexes. VO₂max exhibited maximum correlation with body height in both the sexes and therefore it was considered as the best independent parameter among all the physical parameters to compute the regression equation for VO₂max. These regression norms are shown in figure 1.

The males have higher value of VO₂max than their female counterparts as also reported in previous studies from the country and abroad (Fox, 1973; Das and Bhattacharya, 1995; Kline et al., 1987; Mcardle et al., 1972). But the values of VO₂max obtained in both sexes is comparatively low indicating that the studied population have lower aerobic capacity and poor physical fitness in respect to Caucasians, Kurds, Yemenites, Europeans, Africans, Japanese, young population of Denmark and Americans (Wyndham et al. 1963; Davies et al. 1972; Kitagawa et al. 1977; Okura and Tanaka 2001; Wassmer and Mookerjee 2002; Uth et al. 2004). The VO₂max of active subjects reported by Sengupta et al. (1974), Das (1968), Banerjee et al. (1974), Walter and Nancy (1983) was much higher than that of the present study. On the other hand the cardiorespiratory fitness obtained in the present population is comparatively higher than male smokers and non-smokers of Kolkata (Chatterjee et al., 1987), female non-smokers of Kolkata (Chatterjee and Chakraborty 1986) and university boys and girls of Kolkata (Chatterjee et al., 2004; Chatterjee et al., 2005).

The physical parameters showed significant correlation with VO₂max as also reported in previous studies (Kitagawa et al., 1977; Banerjee et al., 1974; Chatterjee et al., 1987; Chatterjee and Chakraborty 1986; Watanabe et al., 1994). This might be the probable cause for having significantly greater VO₂max among males as they in turn showed significantly higher values of physical parameters (except age) than their female counterparts. In the present population, maximum correlation of VO₂max was obtained with body height in both the sexes and therefore body height was considered as the best parameter to compute the prediction norm for VO₂max among the young college students of Uttar Pradesh, India (Fig 1).

The present investigation depicted that the young college students of Uttar Pradesh, India have normal cardiorespiratory fitness which is well correlated with physical parameters with males having superiority than their female counterparts. Prediction norm for VO₂max computed in both the sexes from body height will help for diagnosis, follow up and treatment of any kind of cardiorespiratory trouble in the studied population.