The Investigation Of The Precaution Of Exercise Preconditioning To The Myocardial Injury Of Military Training Personnel Due To The High Intensity Exercise

ObjectiveTo investigate the influence factors of the cardiac injury due to the exercise and the protective effect of the exercise preconditioning. Methods1.We conducted the psychological assessment for the soldiers in the high altitude training base through the scl-90 scale and record the ECG at three different time which are before exercise, after exercise instantly and 24 hours after exercise.The uncomfortable symptoms were recorded in the symptom assessment scale. Then we analyzed the changes of the ECG scores at different time and conducted correlation analysis among the scores of the scl-90 scale, the ECG scores and the scores of the uncomfortable symptoms.2.Thirty soldiers who come from a high altitude training base and had not gone throuh high intensity exercise for a week were randomly chosen. 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. Results1.The scores of the psychological scale had no significant correlation with that of the ECG at different time(P>0.05), but they had significant correlation with that of the uncomfortable symptoms(P<0.05).The scores of the ECG recorded after exercise instantly were significantly higher than that recorded before exercise and 24 hours after exercise(P<0.05).There was no significant difference between the scores of the ECG recorded before exercise and that recorded 24 hours after exercise(P>0.05).The ECG scores of the soldiers in different psychological status groups had no significant difference at the time of before exercise and after exercise instantly(P>0.05), however the ECG scores of the soldiers with the total average score of the scl-90 scale score lower than 1.44 were significantly lower than that of the soldiers with the total average score of the scl-90 scale score higher than 1.44(P<0.05). The ECG scores of the soldiers of different army time had no significant difference at different time(P>0.05).2.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. Conclusion1.The exhausted exercise has significant influence on the changes of the ECG; The soldiers have a good tolerance to the exhausted exercise, for the changes of the ECG return to normal 24 hours after exercise; The army time factors and psychological factors have no significant influence on the changes of the ECG; The higher the scores of the scl-90 scale are, the soldiers are more prone to developing uncomfortable symptoms, which indicates that it’s of great significance to make psychological counseling among the soldiers before exhausted exercise.2.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.