How do I not lose motivation?

Keep reminding yourself of that goal that you want to achieve and how good would you feel and how would it impact you when you achieve it then tell yourself...."One more"..and keep going then when you feel like giving up... tell yourself.." One more" and keep going......and to motivate yourself more..try to use whatever your trying to achieve small goals until you reach your main goal...

Walk around your neighborhood, whistling Yankee Doodle as loud as you can. When you hear the barks of a pitbull coming towards you, run! How's that for motivation?