Relationship between Ruffier index-derived fitness levels and resting cardiovascular performance in young adults

Abstract

Purpose of the work. Physical fitness plays a crucial role in cardiovascular health, influencing stroke volume (SV), cardiac output (CO), heart rate (HR), and blood pressure. The Ruffier Index (RI) is a simple, field-based measure of cardiovascular efficiency, but evidence linking RI-assessed fitness to resting SV and CO in young adults is limited. This study aimed to investigate the relationship between RI-derived fitness levels and resting cardiovascular parameters (SV, CO, HR, SBP, DBP) in healthy young adults, and to examine potential sex-specific differences. Methodology. A cross-sectional study was conducted with 51 healthy students (28 women, 23 men) from Pomeranian University in Słupsk, Poland (mean age: 20.8 ± 4.2 years for women; 19.9 ± 2.9 years for men). Physical fitness was classified using the RI into very good, good, average, and poor categories. Resting SBP, DBP, HR, SV, and CO were measured under standardised conditions. SV was calculated using the Starr formula, and CO was derived from SV × HR. Statistical analyses included ANOVA, post hoc Tukey tests, Pearson correlations, and linear/multivariate regression models with sex and blood pressure as covariates.