To me, the most exciting (for the city and for the owners) option would be some retail space, maybe 17,500-20,000 sq ft of rentable space for tenants such as a restaurant or sandwich shop, a dentist/salon, a boutique gym, niche retail, etc. 

For someone wanting to put in gym equipment you might check out the cost of local gyms along with the convenience of having that space right in your home.

Literally move in ready, and many also usually have co-working spaces as well as gyms etc.

Add storage and/or gyms to raise rent. 

Property owners get a set number of guest passes to the SROA waterpark, gym, surf wave, etc.

Footprints are shrinking for soft goods, but gyms, trampoline parks and other "fun" are backfilling a lot of those boxes.All that said, there is pretty strong data indicating that DTC brands begin to struggle with customer acquisition costs around $10MM annual sales if they don't have brick and mortar stores.

The gyms are closed, but he's looking for ANY gym that will let him work out.

Don't you have staff for the gym?

Home gyms will also be making a comeback and require additional living space. 

Shares in Planet Fitness, the largest gym operator in the U.S., fell more than 70% last month.