Autonomic Modulation and Body Composition in Educators: Physiological Associations in the Workplace Context
Estela Álvarez‐Gallardo, Andrea Calderón García, Pilar González‐Sanz, Pedro Belinchón‐deMiguel, Vicente Javier Clemente‐SuárezABSTRACT
Purpose
This study examined the relationship between body composition and cardiac autonomic nervous system activity in educators. The objective was to explore the associations between body fat mass (BFM) and fat‐free mass (FFM) with different heart rate variability (HRV) indices in a sample of educators and to assess whether FFM moderates the relationship between BFM and autonomic function.
Method
A descriptive cross‐sectional study was conducted with 253 educators from compulsory and higher education institutions during the 2022–2023 academic year. Autonomic regulation was assessed via HRV, and body composition was measured using bioelectrical impedance analysis.
Findings
Individuals with higher fat mass exhibited less favorable autonomic modulation, evidenced by lower values of the root mean square of successive differences (RMSSD), a time‐domain index that reflects parasympathetic activity and the recovery capacity of the autonomic nervous system. Those with greater fat mass also showed a higher mean heart rate, whereas participants with higher FFM displayed more efficient cardiac activity, with lower mean, minimum, and maximum heart rates. In addition, FFM partially moderated the relationship between BFM and mean heart rate. By contrast, a higher total body water content was associated with a shift toward sympathetic dominance, reflected in higher low‐frequency (LF) components—which represent a mixture of sympathetic and parasympathetic activity—and lower high‐frequency (HF) components, which predominantly reflect parasympathetic activity. Conversely, individuals with higher FFM presented lower mean, minimum, and maximum heart rates, suggesting more efficient autonomic cardiac regulation.
Conclusion
Overall, the findings demonstrate that body composition—particularly FFM and BFM—significantly influences HRV and autonomic nervous system modulation in educators, underscoring the importance of considering body composition in the assessment of autonomic function and in the design of personalized health strategies.