RESUMO

It is well established that endurance exercise has positive effects on cardiac autonomic function (CAF). However, there is still a dearth of information about the effects of regular high-intensity interval training combined with different types of exercises (HIITCE) on CAF. OBJECTIVE: The aim of this study is to compare CAF at rest, its reactivity, and reactivation following maximal exercise testing in HIITCE and endurance athletes. METHODS: An observational study was conducted with 34 male athletes of HIITCE (i.e., CrossFit®) [HG: n = 18; 30.6 ± 4.8 years] and endurance athletes (i.e., triathlon) [TG.: n = 16; 32.8 ± 3.6 years]. We analyzed 5 min of frequency-domain indices (TP, LF, HF, LFn, HFn, and LF/HF ratio) of heart rate variability (HRV) in both supine and orthostatic positions and its reactivity after the active orthostatic test. Post-exercise heart rate recovery (HRR) was assessed at 60, 180, and 300 s. Statistical analysis employed a non-parametric test with a p-value set at 5%. RESULTS: The HG showed reduced HFn and increased LFn modulations at rest (supine). Overall cardiac autonomic modulation (TP) at supine and all indices of HRV at the orthostatic position were similar between groups. Following the orthostatic test, the HG showed low reactivity for all HRV indices compared to TG. After the exercise, HRR does not show a difference between groups at 60 s. However, at 180 and 300 s, an impairment of HRR was observed in HG than in TG. CONCLUSION: At rest (supine), the HG showed reduced parasympathetic and increased sympathetic modulation, low reactivity after postural change, and impaired HRR compared to TG.

Assuntos

RESUMO

Physical inactivity is considered a risk factor for cardiovascular disease and is strongly associated with changes in arterial structure. Regular physical activity and exercise contributes to the prevention of coronary artery disease. Therefore, cardiovascular and resistance training improve hemostatic parameters and promote a less thrombotic blood profile. This review highlights the studies, mechanisms, and outcomes relating to the effectiveness of resistance training on the process of hemostasis. The Pubmed, Scopus, Medline, Scielo, Lilacs, Ibecs, and Cochrane databases were used to locate the original articles. Seventeen studies were found during the research process. Of these, ten articles were excluded. Those protocols using a high volume of training for young adults showed a greater fibrinolytic response, and training protocols with intensities above 80% of 1 maximum repetition showed an increased platelet activity. In subjects with coronary artery disease, just one session of resistance training resulted in improvement in the fibrinolytic system (tissue plasminogen activator) without raising potential thrombotic markers.