Heart rate variability in smokers, sedentary and aerobically fit individuals

Abstract

To test the hypothesis that certain lifestyles may affect cardiovascular regulatory mechanisms, heart rate variability (HRV) among three age-matched groups with different lifestyles (smoking, sedentary and aerobically fit) were compared. Heart rate variability was defined as the difference in heart rate during inhalation vs. exhalation. Heart rate was obtained from normal RR intervals, using a continuous electrocardiogram recording, while subjects were seated and breathing at an augmented tidal volume, and also while subjects were standing and breathing at normal tidal volumes. In the physically active group, heart rate variability was significantly elevated at rest as well as during some of the autonomic tests, when compared to the sedentary and smoker groups (p < 0.05). A hypothesis to explain this finding is that smoking or a sedentary lifestyle reduces vagal tone, whereas a physically active lifestyle, resulting in enhanced aerobic fitness, increases vagal tone. These findings may have cardiovascular health implications.

Exercise training favourably affects autonomic and blood pressure responses during mental and physical stressors in African-American men

“…VO 2 peak and AC, even among older individuals who take part in endurance training. [19][20][21] These findings are evident in the present investigation in which AC, in a highly sympathetically innervated artery, was significantly greater following aerobic training during the CPFt and CCT tests.…”

“…[8][9][10][11][12] Our prior study has demonstrated an augmentation in parasympathetic or vagal modulation and enhanced baroreflex sensitivity (BRS) and arterial compliance (AC) following aerobic training. [13][14][15][16][17][18][19][20][21] Not surprisingly, few of these studies assessed these effects in African-American men, not in populations other than whites. Accordingly, our aim was to determine the extent of benefit that could be achieved in young normotensive AA men, matched for a family history of hypertension.…”

Does Heart Rate Variability Change in Angina Pectoris Patients Treated with Spinal Cord Stimulation?

“…Because of the pain reduction produced by spinal cord stimulation, the patients increased their daily activities, which resulted in an increased mean heart rate during the day (table 1). It is known that physically active people have elevated heart rate variability compared to sedentary people [19], but in our patients an increase in any of the tested parameters of heart rate variability was not found despite their increased daily activity for more than 1 year.…”

Device-guided breathing exercises in the control of human blood pressure

“…Slow breathing can also result in increased parasympathetic activity and vagal tone and/or reduced sympathetic activation as a result of attenuation of the RSA as observed in studies of heart rate [12]. However, although some studies demonstrate concomitant reductions in BP and heart rate following slow breathing training [11], others do not [16].…”

“…The mechanism of action proposes an effect on the reflex control of the cardiovascular system via adaptation of pulmonary stretch receptors and the baroreflex response [11]. Studies of heart rate demonstrate that slow breathing results in increased parasympathetic activity and vagal tone and/or reduced sympathetic activation as a result of attenuation of the respiratory sinus arrhythmia (RSA) [12]. However, studies assessing the efficacy of slow breathing training per se demonstrate reductions in BP but not heart rate prompting the proposal of a vascular rather than cardiac reflex influence [10,13,14].…”