Exercise

Being stuck indoors has really opened my eyes to the importance of being able to get a good cardio workout at home.

I can imagine many scenarios where keeping up your cardio in a confined space would be important in a shtf situation.

In a pandemic situation worse than covid-19 (say Ebola), you might be required to stay isolated in your home for months on end. However looting or civil unrest might require instant mobilization.

Being Stuck in a bunker for months on end, not able to contact anyone else might have a bad effect on your mind and body (as certain people are continuing to prove during this pandemic).
Imagine being stuck in a bunker for a year or more after a nuclear or biological attack).