Solve the problem of elastic rope


I have a pair of pajama pants, after using a long time embedded elastic rope loose, after replacing the same situation will be encountered again after a short time, I want to get rid of this dilemma of frequent replacement of elastic rope. I thought of two methods, method 1: replace the good quality elastic rope (economic conditions do not allow) method 2: the use of ordinary rope instead (although there is no longer the problem of losing elasticity, but still need to re-connect each time you wear pajama pants), what can be a more complete solution to this problem?(see figure)