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To investigate the protective effect of the exercise preconditioning to the myocardial injury of military training personnel due to the high intensity exercise.
The subject object went through two armed 5 km training and they went through adaptive training before high intensity exercise at one time. The soldiers didn't go through other high intensity exercise except for the armed 5 km training during the experiment time. After the 5 km training finished, the dynamic electrocardiogram instrument was worn on the soldiers. The uncomfortable symptoms table were recorded 24 hours later after the 5 km training finished. Compare the difference of the HRV, the total number of beats, the mean heart rate, the uncomfortable symptoms score, the ECG score after the two 5 km training. Compare the difference of the rate of arrhythmia and the rate of ST-T changes. Do Correlation analysis between the HRV and other index.
Armed 5 kilometers before training without preconditioning training group and armed 5 kilometers before training after training preconditioning group heart rate variability, symptoms score, the score of ECG had significant difference (P<0.05), total heart rate and average heart rate had no significant difference (P>0.05); Armed 5 kilometers before training after preconditioning the training group of sinus arrhythmia, ventricular premature beat, ST-T change rate was less than 5 kilometers armed before training without pre adaptation training group (P<0.05), armed 5 kilometers before training without preconditioning training group and armed 5 kilometers before training after the pre adaptation training group the incidence of atrial premature beat had no significant difference (P>0.05); Armed 5 kilometers before training without pre adaptation training group the correlation analysis of heart rate variability and cardiac total number, average heart rate, symptoms score and the score of ECG. Results: r=0.166, P>0.05; r=0.200, P>0.05; r=0.616, P<0.05; r=0.622,P<0.05. Armed 5 km training a set of training heart rate variability and total cardiac preconditioning, average heart rate, discomfort symptom score and the score of ECG correlation analysis Results: r = 0.232, P < 0.05; r=0.272, P > 0.05; r = 0.647, P < 0.05; r = 0.658, P<0.05.
High intensity exercise after pre adaptation training could make training heart rate variability (HRV) improved, reduce the incidence of arrhythmia and ST-T changes, and reduce the score of ECG and unwell symptom score, suggesting that exercise preconditioning has a positive role in the precaution of heart injury due to exercise; Twice after high intensity training heart rate variability have significant correlation to unwell symptom score and the score of ECG, indicating heart rate variability could be treated as early warning indicators of exercise-induced cardiac injury. After pre exercise adaptation training heart rate variability (HRV) improvement is the possible mechanism of exercise-induced cardiac damage protective effect.