Effect of Intensity on Changes in Cardiac Autonomic Control of Heart Rate and Arterial Stiffness After Equated Continuous Running Training Programs

Abstract

Background: It is well known that exercise training has positive effects on both cardiac autonomic function and arterial stiffness (AS). However, it is not clear that which exercise training variables, intensity or volume, or both, play a crucial role in this regard. This study investigates the chronic effects of high-volume moderate-intensity training (HVMIT) and low-volume high-intensity training (LVHIT) on heart rate variability (HRV) and AS in sedentary adult men.Materials and Methods: Notably, 45 males (age: 42 ± 5.7 years) were randomly assigned to a control (n = 15), HVMIT (n = 15), or LVHIT (n = 15). The HVMIT group ran three times per week on a treadmill at 50–60% of VO2max for 45–60 min, while the LVHIT trained at 70–85% of VO2max for 25–40 min. Both training protocols were equated by caloric expenditure. HRV, pulse wave velocity (PWV), hemodynamic variables, and body composition were measured before and after 12 weeks.Results: Both protocols (i.e., HVMIT and LVHIT) significantly increased the SD of normal sinus beat intervals (SDNN) and high-frequency (HF) bands (p < 0.05) after 12 weeks. Whereas the low-frequency (LF)-HF ratio decreased significantly in both training protocols (p < 0.05); however, these changes were significantly greater in the LVHIT protocol (p < 0.05). Furthermore, the root mean square of successive RR interval differences (RMSSD) significantly increased only in the LVHIT (p < 0.05). Moreover, a significant decrease in LF and PWV was only observed following the LVHIT protocol (p < 0.05). Some measures of HRV and PWV were significantly correlated (r = 0.275–0.559; p < 0.05).Conclusion: These results show that the LVHIT protocol was more efficient for improving HRV variables and PWV than the HVMIT protocol after 12 weeks of continuous running training. Interestingly, changes in some HRV parameters were related to changes in PWV. Further studies should elaborate on the link between central and peripheral cardiovascular adaptations after continuous and intermittent training regimens differing in intensity.

Remote, Whole-Body Interval Training Improves Muscular Endurance and Cardiac Autonomic Control in Young Adults

“…The authors concluded that constant aerobic exercise was not enough stimulus to unveil cardiac functional gains in the interceded sample. Likewise, other reports denoted that 12 weeks of intervention induces HR reduction in age-matched subjects, such as in our sample [ 41 , 47 ]. Thus, a more-prolonged, unsupervised program could have helped to denote a major significance in HR reduction.…”

“…Nevertheless, the RMSSD and HF were not modified in either HIIT intervention. Unlike the other reports, our study utilized 14 and 21 min of total volume per session, a minor time employed in comparison to other authors who applied larger volume durations in their programs (~25–60 min) [ 41 , 52 ]. The null effects of HIIT-14 on HRV variables were compatible with the experiments conducted by Soltani et al, where the researchers determined that HRV adaptations are intensity- and volume-dependent [ 41 ].…”

“…While this physiological marker is a good indicator of cardiovascular health, muscle strength, and endurance, there are other elements necessary to survey physical fitness and performance [ 38 , 39 , 40 ]. Both variables have shown significant improvements in a controlled-environment manner [ 38 , 41 , 42 ]. However, the effects of remote, home-based HIIT on both cardiac and muscular endurance, while keeping the safety measures of the COVID-19 lockdown, is incipient.…”

Does Exercise Training Improve Cardiac-Parasympathetic Nervous System Activity in Sedentary People? A Systematic Review with Meta-Analysis

“…Briefly, electronic database searches retrieved a total of 9201 references after deleting duplicates. Sixty-seven studies were selected after reviewing titles and abstracts, of which, 26 were included in the qualitative synthesis after reviewing the full-text [ 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ] and 41 were excluded as follows: (a) participants ( n = 12); (b) interventions ( n = 11); (c) comparison ( n = 7); (d) outcomes ( n = 7); (e) data previously published ( n = 2) and (f) language ( n = 2). Out of all the studies included in the qualitative synthesis, seven were excluded from the quantitative synthesis due to insufficient information to calculate the ES ( n = 5) [ 65 , 71 , 75 , 76 , 86 ] or the findings reported were not pooled ( n = 2) [ 72 , 82 ].…”

“…Included studies were published from 1995 to 2022. Out of all the 26 studies included [ 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ], 20 (77%) were randomised [ 66 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ] and six (23%) were non-randomised [ 65 , 67 , 77 , 78 , 79 , 80 ]. Eleven studies (42%) recruited exclusively male participants [ 67 , 70 , 71 , 74 ,…”