Meeting international self-report muscle strengthening guidelines is associated with better cardiovagal baroreflex sensitivity in adults

Abstract

Engaging in muscle strengthening activities (e.g., resistance training) at least twice/week is promoted by (Inter)national movement guidelines. Cardiovagal baroreflex sensitivity (cvBRS) reflects the ability to modulate R-R interval in response to changes in systolic blood pressure. Given the current conflicting literature, this study posed to explore the relationship between self-report muscle strengthening frequency and spontaneous cvBRS. 114 adults (62 females; age: 33 ± 19 years, 22% >55 years; body mass index: 24.2 ± 3.7 kg/m²) self-reported their weekly muscle strengthening activity frequencies via the Physical Activity and Sedentary Behaviour Questionnaire. Supine beat-by-beat R-R intervals [electrocardiography; 1.00 ± 0.18 s (0.90-1.50 s)] and systolic blood pressure [via finger photoplethysmography; 116 ± 11 mmHg (93-151 mmHg)] were recorded for 10.7 ± 2.0 min (5.3-14.5 min). Spontaneous cvBRS was assessed using the sequence technique. Data were analyzed using multiple regressions adjusted for age, sex, body mass index. Participants completed 2 ± 2 (0-7) days/week of muscle strengthening activities (56% met guidelines), and average overall cvBRS was 14.9 ± 9.1 (3.1-48.4) ms/mmHg. Higher reported frequencies were positively associated with overall cvBRS (Adjusted R² = 0.40, p < 0.001; β = 2.24, p < 0.001). Meeting muscle strengthening activity guidelines was associated with improved overall cvBRS (Adjusted R² = 0.29, p < 0.001; β = 7.68, p < 0.001). All results were unchanged if cvBRS for up-sequences or down-sequences only were used (all, p < 0.001). In conclusion, engaging in muscle strengthening exercises and particularly meeting existing guidelines were associated with better beat-by-beat vagally-mediated blood pressure regulation.

Keywords: autonomic function; blood pressure regulation; cardiovagal baroreceptor sensitivity; physical activity guidelines; resistance training.

Figure 1

Multiple regression of muscle strengthening frequency and spontaneously measured cardiovagal baroreflex sensitivity. Participants (n = 114, 62 females) are grouped by age and sex, with triangles representing males, circles representing females, grey representing those 55 years or younger, and white representing those over 55 years. The multiple regression included moderate-to-vigorous physical activity, age, sex, and body mass index as covariates.

Figure 2

Comparing the spontaneously measured cardiovagal baroreflex sensitivity of those who met muscle strengthening guidelines to those who did not. Participants (n = 114, 62 females) are grouped by sex and age with triangles representing males, circles representing females, grey representing those 55 years or younger, and white representing those over 55 years. Mean and standard deviation of each group, those that did not meet guidelines and those that did are represented by the large black circles. The multiple regression included moderate-to-vigorous physical activity, age, sex, and body mass index as covariates.