Compared to men, women demonstrated smaller heart rate (8 vs 18 beats/min) and mean arterial pressure (3 vs 11 mmHg) responses to 35% maximal voluntary contraction handgrip exercise (P<0.05).
Observational (n=17)
Do men and women differ in forebrain and cardiovagal responses at the onset of isometric handgrip exercise?
Women exhibit smaller cardiovascular responses to isometric exercise compared to men, which is associated with stronger suppression of dorsal anterior cingulate cortex activity.
Absolute Event Rate: 8% vs 18%
p-value: p=<0.05
In general, cardiac regulation is dominated by the sympathetic and parasympathetic nervous systems in men and women, respectively. Our recent study had revealed sex differences in the forebrain network associated with sympathoexcitatory response to baroreceptor unloading. The present study further examined the sex differences in forebrain modulation of cardiovagal response at the onset of isometric exercise. Forebrain activity in healthy men (n = 8) and women (n = 9) was measured using functional magnetic resonance imaging during 5 and 35% maximal voluntary contraction handgrip exercise. Heart rate (HR), mean arterial pressure (MAP), and muscle sympathetic nerve activity (MSNA) were collected in a separate recording session. During the exercise, HR and MAP increased progressively, while MSNA was suppressed (P < 0.05). Relative to men, women demonstrated smaller HR (8 +/- 2 vs. 18 +/- 3 beats/min) and MAP (3 +/- 2 vs. 11 +/- 2 mmHg) responses to the 35% maximal voluntary contraction trials (P < 0.05). Although a similar forebrain network was activated in both groups, the smaller cardiovascular response in women was reflected in a weaker insular cortex activation. Nevertheless, men did not show a stronger deactivation at the ventral medial prefrontal cortex, which has been associated with modulating cardiovagal activity. In contrast, the smaller cardiovascular response in women related to their stronger suppression of the dorsal anterior cingulate cortex activity, which has been associated with sympathetic control of the heart. Our findings revealed sex differences in both the physiological and forebrain responses to isometric exercise.
Wong et al. (Fri,) conducted a observational in Healthy (n=17). Female sex vs. Male sex was evaluated on Heart rate response to 35% maximal voluntary contraction (beats/min) (p=<0.05). Compared to men, women demonstrated smaller heart rate (8 vs 18 beats/min) and mean arterial pressure (3 vs 11 mmHg) responses to 35% maximal voluntary contraction handgrip exercise (P<0.05).