Static exercise of the lower limbs significantly increased systolic blood pressure and vagal-modulated heart rate variability compared to dynamic exercise at matched heart rates.
Does static exercise compared to dynamic exercise at similar heart rate levels elicit different autonomic responses (blood pressure and heart rate variability) in healthy males?
Static and dynamic exercise elicit qualitatively different autonomic control processes and blood pressure responses even when matched for heart rate, with static exercise inducing stronger vagal cardiac activity and sympathetic vascular efferent activity.
Absolute Event Rate: 158% vs 140.2%
p-value: p=<0.001
UNLABELLED: Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heart rate (HR) response. METHOD: 23 males performed two kinds of voluntary exercise in a supine position at similar heart rates: static exercise (SE) of the lower limbs (static leg press) and dynamic exercise (DE) of the lower limbs (cycling). Subjective effort, systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), rate pressure product (RPP) and the time between consecutive heart beats (RR-intervals) were measured. Time-domain (SDNN, RMSSD), frequency-domain (power in the low and high frequency band (LFP, HFP)) and geometric measures (SD1, SD2) as well as non-linear measures of regularity (approximate entropy (ApEn), sample entropy (SampEn) and correlation dimension D2) were calculated. RESULTS: Although HR was similar during both exercise conditions (88±10 bpm), subjective effort, SBP, DBP, MAP and RPP were significantly enhanced during SE. HRV indicators representing overall variability (SDNN, SD 2) and vagal modulated variability (RMSSD, HFP, SD 1) were increased. LFP, thought to be modulated by both autonomic branches, tended to be higher during SE. ApEn and SampEn were decreased whereas D2 was enhanced during SE. It can be concluded that autonomic control processes during SE and DE were qualitatively different despite similar heart rate levels. The differences were reflected by blood pressure and HRV indices. HRV-measures indicated a stronger vagal cardiac activity during SE, while blood pressure response indicated a stronger sympathetic efferent activity to the vessels. The elevated vagal cardiac activity during SE might be a response mechanism, compensating a possible co-activation of sympathetic cardiac efferents, as HR and LF/HF was similar and LFP tended to be higher. However, this conclusion must be drawn cautiously as there is no HRV-marker reflecting "pure" sympathetic cardiac activity.
Weippert et al. (Fri,) conducted a other in Healthy (n=23). Static exercise (isometric leg press) vs. Dynamic exercise (cycling at matched heart rate) was evaluated on Systolic blood pressure (SBP) [mmHg] (p=<0.001). Static exercise of the lower limbs significantly increased systolic blood pressure and vagal-modulated heart rate variability compared to dynamic exercise at matched heart rates.