Controlled 5-mo aerobic training improves heart rate but not heart rate variability or baroreflex sensitivity

2000 ◽  
Vol 89 (5) ◽  
pp. 1825-1829 ◽  
Author(s):  
Antti Loimaala ◽  
Heikki Huikuri ◽  
Pekka Oja ◽  
Matti Pasanen ◽  
Ilkka Vuori

Endurance-trained athletes have increased heart rate variability (HRV), but it is not known whether exercise training improves the HRV and baroreflex sensitivity (BRS) in sedentary persons. We compared the effects of low- and high-intensity endurance training on resting heart rate, HRV, and BRS. The maximal oxygen uptake and endurance time increased significantly in the high-intensity group compared with the control group. Heart rate did not change significantly in the low-intensity group but decreased significantly in the high-intensity group (−6 beats/min, 95% confidence interval; −10 to −1 beats/min, exercise vs. control). No significant changes occurred in either the time or frequency domain measures of HRV or BRS in either of the exercise groups. Exercise training was not able to modify the cardiac vagal outflow in sedentary, middle-aged persons.

2020 ◽  
Vol 45 (4) ◽  
pp. 431-436
Author(s):  
Danilo Fernandes da Silva ◽  
Shuhiba Mohammad ◽  
Kelly Ann Hutchinson ◽  
Kristi Bree Adamo

Traditionally, resting heart rate variability (rHRV) is measured for 10 min using the last 5 min for analyses (e.g., criterion period). It is unknown whether the measurement period can be shortened in pregnant women as there are currently no established standards. We aimed to compare shorter time segments (e.g., from the 1st to 10th minutes) of the parasympathetic index natural logarithm transformation of root mean square of successive R–R differences (Ln rMSSD) with the criterion period in pregnant and nonpregnant women. Twelve pregnant (age: 30.8 ± 3.4 years; gestational age: 20.1 ± 5.0 weeks) and 15 nonpregnant women (age: 29.8 ± 4.0 years) were included. rHRV was measured using a portable heart rate monitor for 10 min while sitting. Ln rMSSD difference/agreement between shorter time segments and criterion period was analyzed. The result observed between the 4th–5th minutes was the shortest time segment not different from/highly agreed with the criterion period in pregnant women (difference [95% confidence interval (CI)]: −0.10 [−0.22 to 0.02]/bias ± 1.96 × SD: −0.06 [−0.38 to 0.25]). In nonpregnant women, the 2nd–3rd-minute segment was the shortest with similar results (difference [95% CI]: −0.04 [−0.15 to 0.07]/bias ± 1.96 × SD: −0.03 [−0.39 to 0.32]). The Ln rMSSD was found to be stable from the 5th–10th minutes and the 3rd–10th minutes in pregnant and nonpregnant women, respectively. A shortened rHRV assessment can increase its applicability in clinical/exercise-training settings. Novelty Ln rMSSD can be measured for 5 min in pregnant women, with the last 1-min segment analyzed. The last 1-min segment from 3 min can be used for rHRV measurement in nonpregnant women. The shortened rHRV assessment can facilitate its applicability in clinical/exercise-training settings.


2021 ◽  
Vol 20 (1) ◽  
pp. 51-61
Author(s):  
Alexandra V. Mashanskaya ◽  
Anna V. Pogodina ◽  
Alina V. Atalyan ◽  
Lyubov V. Rychkova ◽  
Olga V. Bugun ◽  
...  

Background. Searching for new strategies for the rehabilitation of adolescents with obesity and comorbid arterial hypertension (AHT) before significant pathological changes development in the cardiovascular system remains the urgent challenge. Objective. The aim of the study was to examine the effect of interval hypoxic training (IHT) on blood pressure (BP) levels in adolescents with overweight / obesity and comorbid AHT. Methods. Adolescents aged 14-17 years with body mass index SDS ≥ 1 and grade I AHT (mean level of systolic and/or diastolic BP ≥ 95th percentile for population of corresponding age, sex and height) have been randomized to the group «aerobic training» (treadmill walking) and “aerobic training + IHT” (usage of hypoxicator in intermittent operation cycles). All patients were on subcaloric diet (10% reduction in caloric intake for given age). Primary outcome measure was the difference between groups on systolic/diastolic BP levels according to 24-hour BP monitoring after completion of training program (10 classes each). The effects of IHT on body composition (bioelectrical impedance analysis), heart rate variability and psychoemotional state (Spielberger scale, assessment of health, activity and mood) were further estimated. Results. 43 patients were assigned to the index group, and 42 — to the control group. 67 patients have completed the research program. 5 patients (12%) from the IHT group and 13 patients (31%; p = 0.029) from the control group prematurely discontinued participation in the trial due to poor exercise tolerance. The groups were comparable in baseline systolic and diastolic BP. Decrease in BP occurred in both groups after 10 workouts. There were no differences in decrease value: mean difference for SBP was 2.4 mm Hg (95% CI -6.6 ... 1.8), for DBP — 0.2 mm Hg (-3.6 ... 4.0). However, the incidence of reaching the targeted SBP (< 95th percentile for the corresponding age and sex) after completion of the treatment was recorded in 66% patients in the experimental group and in 42% patients in the control group (p = 0,047). Positive dynamics in several indicators of heart rate variability and psychoemotional state were mentioned in the IHT group. Conclusion. The IHT implementation in the complex of rehabilitation program for adolescents with overweight / obesity and AHT has no additional positive effect on BP levels. However, the incidence of reaching the targeted SBP (< 95th percentile for the corresponding age and sex) after completion of the treatment was recorded in 66% patients in the experimental group and in 42% patients in the control group (p = 0,054).


2019 ◽  
Vol 33 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Stefan Duschek ◽  
Alexandra Hoffmann ◽  
Casandra I. Montoro ◽  
Gustavo A. Reyes del Paso

Abstract. Chronic low blood pressure (hypotension) is accompanied by symptoms such as fatigue, reduced drive, faintness, dizziness, cold limbs, and concentration difficulties. The study explored the involvement of aberrances in autonomic cardiovascular control in the origin of this condition. In 40 hypotensive and 40 normotensive subjects, impedance cardiography, electrocardiography, and continuous blood pressure recordings were performed at rest and during stress induced by mental calculation. Parameters of cardiac sympathetic control (i.e., stroke volume, cardiac output, pre-ejection period, total peripheral resistance), parasympathetic control (i.e., heart rate variability), and baroreflex function (i.e., baroreflex sensitivity) were obtained. The hypotensive group exhibited markedly lower stroke volume, heart rate, and cardiac output, as well as higher pre-ejection period and baroreflex sensitivity than the control group. Hypotension was furthermore associated with a smaller blood pressure response during stress. No group differences arose in total peripheral resistance and heart rate variability. While reduced beta-adrenergic myocardial drive seems to constitute the principal feature of the autonomic impairment that characterizes chronic hypotension, baroreflex-related mechanisms may also contribute to this state. Insufficient organ perfusion due to reduced cardiac output and deficient cardiovascular adjustment to situational requirements may be involved in the manifestation of bodily and mental symptoms.


1997 ◽  
Vol 273 (6) ◽  
pp. H2627-H2631 ◽  
Author(s):  
Acácio Salvador Véras-Silva ◽  
Katt Coelho Mattos ◽  
Nilo Sérgio Gava ◽  
Patricia Chakur Brum ◽  
Carlos Eduardo Negrão ◽  
...  

The decrease in cardiac sympathetic tone and heart rate after low-intensity exercise training may have hemodynamic consequences in spontaneously hypertensive rats (SHR). The effects of exercise training of low and high intensity on resting blood pressure, cardiac output, and total peripheral resistance were studied in sedentary ( n = 17), low- ( n = 17), and high-intensity exercise-trained ( n = 17) SHR. Exercise training was performed on a treadmill for 60 min, 5 times per week for 18 weeks, at 55% or 85% maximum oxygen uptake. Blood pressure was evaluated by a cannula inserted into the carotid artery, and cardiac output was evaluated by a microprobe placed around the ascending aorta. Low-intensity exercise-trained rats had a significantly lower mean blood pressure than sedentary and high-intensity exercise-trained rats (160 ± 4 vs. 175 ± 3 and 173 ± 2 mmHg, respectively). Cardiac index (20 ± 1 vs. 24 ± 1 and 24 ± 1 ml ⋅ min−1 ⋅ 100 g−1, respectively) and heart rate (332 ± 6 vs. 372 ± 14 and 345 ± 9 beats/min, respectively) were significantly lower in low-intensity exercise-trained rats than in sedentary and high-intensity exercise-trained rats. No significant difference was observed in stroke volume index and total peripheral resistance index in all groups studied. In conclusion, low-intensity, but not high-intensity, exercise training decreases heart rate and cardiac output and, consequently, attenuates hypertension in SHR.


2017 ◽  
Vol 49 (5S) ◽  
pp. 908-909
Author(s):  
Luis Andrés Téllez-T ◽  
Diana Camelo-Prieto ◽  
Alejandra Tordecilla-Sanders ◽  
Jorge E. Correa-Bautista ◽  
Robinson Ramírez-Vélez ◽  
...  

2019 ◽  
Vol 126 (5) ◽  
pp. 1272-1280 ◽  
Author(s):  
Jon Egelund ◽  
Michael Nyberg ◽  
Camilla M. Mandrup ◽  
Jawdat Abdulla ◽  
Bente Stallknecht ◽  
...  

We examined the influence of recent menopause and aerobic exercise training in women on myocardial perfusion, left ventricular (LV) dimension, and function. Two groups ( n = 14 each) of healthy late premenopausal (50.2 ± 2.1 yr) and recent postmenopausal (54.2 ± 2.8 yr) women underwent cardiac magnetic resonance imaging (cMRI) at baseline and after 12 wk of high-intensity aerobic training. Measurements included LV morphology, systolic function, and myocardial perfusion at rest and during an adenosine stress test. At baseline, resting myocardial perfusion was lower in the postmenopausal than the premenopausal group (77 ± 3 vs. 89 ± 3 ml·100 g−1·min−1; P = 0.01), while adenosine-induced myocardial perfusion was not different ( P = 0.81). After exercise training, resting myocardial perfusion was lower in both groups (66 ± 2; P = 0.002 vs. 81 ± 3 ml·100 g−1·min−1; P = 0.03). The adenosine-induced change in myocardial perfusion was lower in the groups combined (by 402 ± 17 ml·100 g−1·min−1; P = 0.02), and the adenosine-induced increase in heart rate was 10 ± 2 beats/min lower ( P < 0.0001) in both groups after training. Normalization of myocardial perfusion using an estimate of cardiac work eliminated the differences in perfusion between the premenopausal and postmenopausal groups and the effect of training. Left ventricle mass was higher in both groups ( P = 0.03; P = 0.006), whereas LV end-diastolic ( P = 0.02) and stroke ( P = 0.045) volumes were higher in the postmenopausal group after training. Twelve weeks of exercise training increased left ventricle mass and lowered resting and adenosine-induced myocardial perfusion, an effect that was likely related to cardiac work. The current data also suggest that the early menopausal transition has limited impact on cardiac function and structure. NEW & NOTEWORTHY This study provides for the first time estimates of myocardial perfusion in late premenopausal and recent postmenopausal women before and after a period of intense aerobic training. Resting myocardial perfusion was lower in postmenopausal than premenopausal women. Training lowered myocardial resting and stress perfusion in both groups, an effect that was likely influenced by the lower heart rate.


Circulation ◽  
2000 ◽  
Vol 102 (21) ◽  
pp. 2588-2592 ◽  
Author(s):  
Ferdinando Iellamo ◽  
Jacopo M. Legramante ◽  
Michele Massaro ◽  
Gianfranco Raimondi ◽  
Alberto Galante

2006 ◽  
Vol 86 (5) ◽  
pp. 626-635 ◽  
Author(s):  
Mei-Wun Tsai ◽  
Wei-Chu Chie ◽  
Terry BJ Kuo ◽  
Ming-Fong Chen ◽  
Jen-Pei Liu ◽  
...  

Abstract Background and Purpose. Cardiac autonomic dysfunction is associated with risk of restenosis and cardiovascular mortality in patients after percutaneous transluminal coronary angioplasty (PTCA). Analysis of heart rate variability (HRV) is an important, widely used method for assessing cardiac autonomic regulation. The purpose of this study was to investigate the effect of exercise training on HRV in subjects after PTCA. Subjects and Methods. A total of 84 subjects who had undergone PTCA were recruited for this study. The subjects (age [mean±SD]=57.0±9.3 years) were randomly assigned to either an exercise group to undergo an 8-week outpatient exercise program or a control group to undergo usual care. Heart rate variability was measured for 5 minutes in the supine resting position at baseline and at the end of 8 weeks. Results. The parasympathetically modulated HRV of the subjects in the exercise group increased significantly compared with the HRV of subjects in the control group. The effects of training on HRV were independent of angioplasty type (balloon or stent) and were unrelated to whether the subjects had received previous PTCA. Discussion and Conclusion. Exercise training can increase parasympathetic modulation of cardiac function in people after they have undergone successful PTCA. Our results suggest that analysis of HRV can be extended to assess the effect of exercise training on cardiac autonomic dysfunction in people after coronary angioplasty.


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