Effects of high intensity military training on cardiovascular system of military personnel

Objective To explore the changes of cardiovascular system of military personnel during highly intensive training. Methods One hundred and seventy officers and soldiers were as research subjects, including 100 individuals in high- intensity group and 70 in control group. The levels of serum cortisol (COR), high sensitivity C-reactive protein (hs-CRP), cardiac- specific Troponin T (cTnT) and human heart fatty acid binding protein (H-FABP) were measured when military training ended. All subjects were tested with fatigue assessment instrument (FAI). The data of blood pressure and electrocardiogram were collected from 40 individuals randomly selected from high-intensity group and 36 from control group before and after training for analyzing the blood pressure, arrhythmia and heart rate variability (HRV). Results The levels of COR (indicator related to stress) and hs-CRP (indicator related to inflammation) were significantly higher in high intensity group than in control group (P<0.05). Highly intensive training can lead to the emergence of myocardial micro-injury, the levels of cTnT and H-FABP were obviously higher than those in control group (P<0.01), and the mean blood pressure and the severity of fatigue status were significantly higher than those in control group (P<0.05). The incidence of severe ventricular arrhythmia was lower in both groups (P=1.000). The average heart rate, total heart beats, total number of atrial premature beat, total number of ventricular premature beat, the incidence of sinus arrhythmia and intermittent second degree type I atrioventricular block were significantly higher in high intensity group than in control group (P<0.05). The HRV of high intensity group was obviously decreased (P<0.01). Conclusion Highly intensive training may induce the military personnel into the state of acute stress and inflammation, which may lead to myocardial injury, increase severity of fatigue status, accompanied with the rise of blood pressure, low HRV and increased incidence of various arrhythmias. DOI: 10.11855/j.issn.0577-7402.2018.04.15