Cardiac Autonomic Function and High-Intensity Interval Training in Middle-Age Men

The study aims to investigate the literature on the effect of high-intensity interval training (HIIT) on cardiac autonomic function in individuals with cardiovascular disease (CVD) and lifestyle disorders. We performed electronic database search from CENTRAL, WoS, Scopus, Pubmed, and PEDro up to 25th February 2021. Randomised control trials/quasi-experimental trials/cross-over trials that assessed the effects of HIIT with control/alternative treatment on cardiac autonomic control were included in this review. A total of 11 studies were included for qualitative analysis and among them, 8 were quantitatively analysed. A random-effect model of standardised mean difference (SMD) and mean difference of the respective outcome measures for cardiac autonomic control was determined. The findings of the qualitative analysis revealed the beneficial effects of HIIT on cardiac autonomic modulation. However, the majority of the studies had an unclear or high risk of bias for randomisation, concealment methods, and blinding of participants to the intervention that could have influenced the interpretation of the findings. The SMD revealed a significant effect of HIIT on standard deviation of N-N intervals (SDNN) (ms) [SMD: 0.40, 95% confidence interval (CI): -0.001 to 0.80, P=0.05], high frequency power (HF) (ms2) [0.46, 95% CI: 0.17 to 0.76, P=0.002], and ratio of low and high frequency power, (LF/HF) [-0.80, 95% CI: -1.27 to -0.33, P=0.0008]. In conclusion, HIIT may effectively modulate cardiac autonomic function by increasing parasympathetic dominance, sympathetic withdrawal, and sympathovagal balance in individuals with CVD and lifestyle disorders. The study has a PROSPERO registration number: CRD42021231225

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Comparison of performance-related responses to an endurance running training between untrained men and women

Archivos de Medicina del Deporte ◽

10.18176/archmeddeporte.00021 ◽

2021 ◽

Vol 38 (1) ◽

pp. 15-21

Author(s):

D Fernandes da Silva ◽

C Segabinazi Peserico ◽

F Andrade Machado

Keyword(s):

High Intensity ◽

Autonomic Function ◽

Interval Training ◽

Cardiac Autonomic Function ◽

High Intensity Interval Training ◽

Endurance Running ◽

Men And Women ◽

Male And Female ◽

Running Training ◽

High Intensity Interval

Introduction: The adherence on endurance running events is increasing exponentially around the World in both previously untrained men and women, thus the incorporation of more appropriate and individualized training approaches are required. It is not known if male and female untrained runners differ in the responses to endurance running training on performancerelated variables. Objective: We aimed to compare performance-related responses to an endurance running training program between untrained men and women. Material and method: Sixteen participants (8 men and 8 women) were paired in the baseline by age, body mass index, and percentage in which time to complete 5 km (t5km) represented from the average of best 50 runners t5km in the greatest regional race for each gender. They completed an 11-week training protocol alternating high-intensity interval training and moderateintensity continuous running, three times per week, in a running track. In the week 1 and 11 of the protocol (baseline and post-training weeks), peak running velocity at treadmill (Vpeak), time limit (tlim) at 100% Vpeak, t5km, and the index rMSSD of heart rate variability (HRV) were measured for cardiac autonomic function. Baseline gender-differences were accounted in the analysis. Results: Male and female significantly improved Vpeak (9.4 ± 1.7% and 7.2 ± 1.7%, respectively) and t5km (-13.0 ± 1.8% for both), and no gender-related differences for the adaptations in these two variables were observed. The tlim at 100% Vpeak and rMSSD did not change across the training period in both groups. Percentage of change for men was “moderately” higher than for women for rMSSD (33.4 ± 40.7% vs. 13.9 ± 21.4%), although statistically non-significant. Conclusion: Men and women responses to training were similar with regards to their running performance and cardiac autonomic function. With regards to practical application, Vpeak and its tlim can be applied in exercise settings for the prescription of moderate- to high-intensity running training with similar benefits regardless of the biological gender

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