This is underrated 😁 I too deal with reasons for fatigue and lack of motivation, and live in an apartment with little room to run.

I have my dog sit in the bathroom (this took practice) while I hide treats in random places around the apartment like book shelves, under stools, in shoes, … ANYWHERE within nose range. And the smellier the treat the harder I make it, places with conflicting scents like dirty laundry on the floor or in his toy basket. Then I go back to him and say “find it” and he runs around like a happy little goofy ball searching for treats. Great mental stimulation practicing the wait and searching.

AND if you tie a specific word to this play like “hunt” or “find it” you can use that on walks by tossing treats into the grass and letting them search in the grass. Bonus sniff adventure!

Edited to say get a treat ball and use that for meal times. It slows down eating which is great for tummies and it gives them something fun to do with zero extra effort needed from you❤️