Ejection Fraction in Echo. Too much?

Sir Recently i done my Echo Report in which my Ejection Fraction is 57%. Earlier about 1 year 8 months ago my EF was 64% in the Echo done then. Though i know that I am really bothered by the fact that my EF declined from 64% to 57%. Is it the point to be worried about? Or does EF change from lab to lab i.e. if i will get the EF tested again then it will return to 64%. What i have read somewhere is that it should be above 60%.please advise. And one more thing is i follow a very active life style i.e. i go for 45 mins high brisk walk with 4 min jogging. Other then that i do 20 min full body stretch. So in total i am following 1hr 10-15 minutes of workout 5 day a week Is that too much? Will that leave any adverse effects on my heart because i have read that some athletes use to develop LEFT VENTRICULAR HYPERTROPHY when they to strenuous activity. Echocardiogram attached herewith for your ready reference.