[Development of a Hebrew questionnaire to be used in epidemiological studies to assess physical fitness--validation against sub maximal stress test and predicted VO2max].

BACKGROUND

The physical activity questionnaire is typically chosen for population studies because it is practical and does not interfere with the behavior of the surveyed individual. This instrument can be adapted for the particular studied population, and in terms of accuracy it is both reliable and valid.

AIM

To develop a valid and appropriate measure to assess physical fitness according to the level of physical activity throughout the day, and to estimate the relation between a subjective questionnaire measurement evaluating physical activity, to predicted VO2max, as an objective measure of physical fitness.

METHODS

Three hundred healthy subjects, 150 men and 150 women, aged 25-65 years old participated in this study. All subjects were routinely examined in the Sheba Medical Center Executive Screening Survey. They were asked to complete a self-administered questionnaire and report on the level of physical activity at work, the level of sports activity and the level of leisure time non-sport activity. The index calculated from the questionnaire was compared to the result from a sub-maximal exercise test, which they performed in The Executive Screening Survey, to composite a valid questionnaire to estimate physical fitness.

RESULTS

A high and statistically significant correlation (r = 0.64, P < 0.01) was found between the indexes of physical activity calculated from the questionnaire to the predicted VO2max, measured from the sub-maximal exercise test. The reliability of the questionnaire was examined by test-retest and a high and statistically significant correlation (r = 0.89, P < 0.01) was found between the first and the proceeding one month administration of the questionnaire. The final modal to predict VO2max included a total index of physical activity, gender, BMI, age and resting heart rate. Overall this model predicted 58% of the VO2max.

CONCLUSIONS

The self-administered questionnaire developed in this study has high construct validity and a significant correlation to predicted VO2max, with high sensitivity in both sexes and among active and non-active subjects. It is therefore an appropriate tool to be used in epidemiological studies.