Cardiorespiratory fitness involves both cardiovascular and respiratory capacities.
However, existing methods have been criticised for reflecting cardiovascular fitness, but not pulmonary fitness.
The objective of this study was to
investigate the relationship between these two testing parameters. Methods:
A cross-sectional population-based physical fitness assessment was conducted in
23 schools. The body height and weight, lung capacity, and step test results of students aged 10-18 were recorded.
Criterion-referenced standards from the China
Sports Bureau were adopted, as they include separate measurements for
cardiovascular and pulmonary fitness.
Results: The Pearson coefficients of lung capacity and the step test
index from 13,028 schoolchildren ranged from 0.007 to 0.086 and from 0.026 to
0.105 for boys and girls, respectively, showing that poor correlations exist
between the two parameters. Cluster analysis resulted in three clusters of
children with similar characteristics. A good degree of similarity was found
between the two parameters in children obtaining an “excellent” grade, but only
a moderate degree of similarity between the
two parameters in those obtaining a “good”,
“pass” or “fail” grade. Conclusion: When cardiovascular fitness and
pulmonary fitness are considered separately,
there is a poor correlation between them, thus indicating further
studies of cardiopulmonary fitness measurements is necessary.