Heterogeneity of cardiorespiratory fitness among Brazilian regions and comparison with Norwegian values

Abstract Introduction Cardiorespiratory fitness (CRF) is an important component of health-related physical fitness, and its reduction is associated with a higher risk of cardiovascular disease and increased mortality. Maximal oxygen consumption (VO2 max) measured in the Cardiopulmonary Exercise Test (CPET) is the gold standard for CRF evaluation. The measured VO2 max is compared to predicted normal reference values to provide an accurate and individualized evaluation and classification. However, predicted values have gender and age differences, and data from different regions and countries can be heterogenous due to different demographic and biopsychosocial characteristics. Purpose To compare reference values of VO2 max in Brazilian and Norwegian population samples do analyze geographical CRF differences. Method Brazilian reference values for CRF were compared within each other and with Norwegian values. The included studies evaluated healthy individual with CPET and direct measurement of VO2 max on a treadmill. Mean, standard deviation and sample size were obtained from the published articles in the last decade, and and standard error of mean (SEM) were calculated. The differences on CRF between studies were analyzed using SEM and the 95% confidence interval. Results Brazilian reference values for CRF were different between each other, with lower values at Northeast region and higher values at Southeast for all age groups and both genders. Midwest region showed CRF with intermediate values between these two regions. Comparisons also revealed different values from Norway, which presented the highest CRF for all age groups and both genders (Pictures 1 and 2). Observed heterogeneity in CRF may be explained by anthropometric differences, as Northeast individuals had lower height than the other Brazilian samples, and the Norwegians were the tallest. Other demographic and biopsychosocial characteristics may also play a role. Conclusion The present study revealed differences on CRF between countries and within Brazilian population, with a negative gradient from southern to northern regions of Brazil. This finding reinforces the appropriateness of adequate use of regional and country specific reference values for VO2 max to ensure a correct CRF evaluation and classification. Funding Acknowledgement Type of funding sources: None.