Difference of Frequency Effect Between Once A Week With SevenTimes A Week Aerobic Exercise to Beta Endorphin Level of MaleLaboratory Rat's Brain Tissue

Background: Physical excrcise not only promotes fitness but also increases brain performance and improves mood through increasing beta endorphin level in brain. it is unknown whether physical exercise’s frequency affects the secretion of beta endorphin. The purpose of this rescarch is to know the effect of aerobic physical exercise, divided into once a weck and seven times a weck group, to beta endorphin level of laboratory rats. Method: This research is a laboratory experimental research with Post Test Contro, Group Design. This research's subjects are 27 male laboratory rats distributed to control group, once a week aerobic group, and seven times a week aerobic group. Physical exercise treatment was given by using treadmill for six weeks, with the speed set on 20m/minutes for 30 minutes. Beta endorphin level was measured using ELISA Kit for RatEndorphin from ELABSCIENCE, followed by independent sample test. Result: There is an increase in the level of beta endorphin of male laboratory rats brain tissue of the once a week aerobic group compared to seven times a week and control groups(45,55± 7.03pg/ml vs 40.00 士 10,61pgml vs 27,11 士 10,46pg/ml). There is a significant difference (p<O,05) in the mean of beta level betiveen experimental groups with control group. However, There is no significant difference in the mean of beta endorphin level between once a week aerobic group with seven time aerobic group (p=0,209). Conclusion: Both once a week and seven times a week acrobic physical exercises affect brain tissue's beta endorphin level. There is no significant difference of brain tissue's beta endorphin level's mean between the rats given different frequency of physical exercise treatment.