I hit a plateau for 5 months. Added practicing more than just one dance, but my limit was to 30 minutes for 4 dances, after Zumba, yoga or walking 6,000 steps. It didn't allow me to mess up because I had limited time. Sometime I broke up my walking with breaking into choreography then walk again. Change up the stair stepper, so you ambush your body at least every once in awhile. Motivation can waiver, that is human nature. Know what the end game is, better posture? Better balance? Stronger bones? Peace in the body rather than stress related muscle tension, stamina,,,,knowing that helps to maintain your course. We've all been there. Good luck.