Meeting Muscle Strengthening Guidelines Is Associated With Better Cardiovagal Baroreflex Sensitivity In Adults

Engaging in muscle strengthening activities (e.g., resistance training) at least twice/week is promoted by (Inter)national movement guidelines for optimal health benefits. Cardiovagal baroreflex sensitivity (cvBRS) reflects the efficiency of modulating R-R interval in response to changes in systolic blood pressure. Despite muscle strengthening exercise being promoted, conflicting reports exist as to whether resistance exercise improves, reduces, or does not alter cvBRS. PURPOSE: To explore whether the frequency of self-reported muscle strengthening exercise and meeting the guidelines of ≥2 sessions/week is associated with spontaneous cvBRS. METHODS: Healthy adults (n = 114, 62♀; age: 33 ± 19 years, 22% > 55-years; body mass index: 24.2 ± 3.7-kg/m2) self-reported weekly muscle strengthening activity frequencies via the Physical Activity and Sedentary Behaviour Questionnaire. Beat-by-beat R-R intervals (electrocardiography; 1.00 ± 0.18-ms) and systolic blood pressure (via finger photoplethysmography; 116 ± 11-mmHg) were recorded for 10.7 ± 2.0-mins. Spontaneous cardiovagal baroreflex sensitivity was assessed using the sequence technique. Data were analyzed using linear regressions adjusted for age, sex, body mass index. RESULTS: Participants completed 2.4 ± 2.1 (0-7) days/week of muscle strengthening activities (56% met guidelines) and overall cvBRS was 14.9 ± 9.1 (3.1-48.4) ms/mmHg. More frequent muscle strengthening activities was positively associated with overall cvBRS (Adjusted R2 = 0.40, p < 0.001; =2.24, p < 0.001). Meeting muscle strengthening activity guidelines was also associated with improved overall cvBRS (Adjusted R2 = 0.29, p < 0.001; =7.68, p < 0.001). All results were unchanged if cvBRS for up-sequences or down-sequences only were used (all, p < 0.001). CONCLUSION: Engaging in muscle strengthening exercises and particularly meeting international guidelines were associated with better beat-by-beat vagally-mediated blood pressure regulation, coinciding with public health guidelines.