Myocardial Damages After 80 Km Mountains Marathon Race

Abstract

PURPOSE Recently, the jogging is popular irrespective of age and sex. A regular jogging has an effective way to improve their health, but there is possibility of sudden death. In Japan, concern about sudden death during marathon run and other exercises has been focused since the end of 2002, when there were many cases of sudden death frequently happened. However there has been little investigation into the degree of cardiac fatigue due to prolonged exercises and the recovery process from cardiac fatigue. Therefore, the rest period after prolonged exercises is generally depending on only each individual's experiences. The purpose of this study is to investigate into the myocardial stress reaction and recovery after an ultra marathon race. METHODS Blood samples for measuring brain natriuretic peptide (BNP) were drawn before, immediately after (I), one days after (1D), three days after (3D) and five days after (5D) the 80 km mountains ultra marathon race. Some recent findings have shown that plasma levels of BNP correlated with myocardial stress. In addition, heart rate (HR) and QT intervals were analyzed from the electrocardiogram (ECG) measured at almost same time as blood drawing. RESULTS Not only the ECG QT intervals immediately after ultra marathon but also that of one day after were prolonged (B:371.3 ± 12.06, I: 378.5 ± 14.45, 1D: 386.6 ± 13.94, p<0.05). It was thought that myocardial electric activity was unstable until one day after the ultra marathon race. BNP reached a peak one day after the marathon race and increased significantly until three days after (B: 3.6 ± 3.35, 1D: 19.3 ± 13.67, 3D: 9.75 ± 5.64p<0.05). CONCLUSIONS After 80km mountain ultra marathon race, subjects who were average jogger level had myocardial damages. The myocardial damage was from a result of the myocardial heavy stress brought by the increased heart rate after prolonged exercise. In order to carry out movement more safely, it needs to take at least three days rest for recovering cardiac fatigue after ultra marathon.