The purpose of this study was to investigate the effects of exhaustive exercise in the morning and evening on the electrical activity of the heart of middle-aged male athletes. This study was based on the quasi-experimental method.The study population included all male athletes in Shiraz.17 athletes were voluntarily selected as the sample size.In this study, the independent variable was the time and exhaustive exercise which was conducted in the morning and evening.The dependent variablesincludedQRS-T-wave changes, PR segment, PR interval, and QTinterval. They were measured in the stages of exhaustion and recovery as a pretest. All the participants were prepared to exercise to the point of maximum exhaustion.They were tested using the Bruce protocol as a routinely used and well-validated exercise treadmill test. There were seven stages in total, and each stage lasted 3 min. There was a progressive increase in workload in terms of speed and incline with each successive stage.The electrical activity of the heart was recorded by electrocardiogram at each stage. The hypotheses were tested using repeated measures ANOVA through SPSS.16 software at the significance level of P £ 0.05.The results showed that there is no significant difference between the variables, including QRS-T-wave changes, PR segment, PR interval, and QT intervalin the morning and evening.
exhaustive exercise, electrocardiogram, men, athlete
An increase in the cardiovascular disease is common in many countries.The disease is the top killer diseases in the world.It is estimated that by 2030 about 23 million people will lose their lives due to cardiovascular disease.In Iran, the highest mortality rate of adult age group is related to cardiovascular disease. Studies show that physical activity as an appropriate method resolves problems with cardiovascular disease. Research has shown that different factors associated with cardiovascular system, such as heart rate and blood pressure, follow a circadian rhythm. There is a relationship between the electrical activity of the heart and the circadian rhythm. The circadian rhythm affectsthe electrical activity of the heart in humans and many other mammals (Pysyvn et al., 2000).
A summary of the inferential findings is presented below:
The findings of this study showed that QRS voltage is significantly reduced after beginning the physical activityin the morning and eveningand this value slightly increases in the recovery status, but it is significantly lower than the pre-test values. Hence, the p-values of the QRS voltage were not significantly different in the pretest in the morning and evening, exhaustion in the morning and evening, and recovery in the morning and evening.
248 total views, 1 views today