Screwing wooden boards into concrete floor in garage gotchas?

Hi all!

So I'm making a little corner area in the garage for a workout space. The house is a three story town-home with the garage in the bottom (at street level).

I was planning on laying down some flat pieces of particle board I salvaged from old garage cabinets. On top of these I'm going to lay down some puzzle-piece style foam mats.

The area is going to be used for boxing and calisthenics, so having the boards and foam move is...not ideal.

I was going to secure the boards into the concrete by drilling a few holes and screwing them in with the wood screws I salvaged from the same cabinets. I don't anticipate a lot of vertical stress, only horizontal one, so I'm hoping these screws are sufficient. The foam mats will be screwed into the wood with shorter wooden screws to ensure they don't shift.

Is this a good idea? Am I setting myself up for something catastrophic in the future? This wouldn't cause any issues with moisture leakage or earthquakes or anything would it? The extent of my DIY experience is pretty much limited to screwing in some toggle bolts into the drywall for a towel holder, so please forgive the noobishness. And thank you much in advance for any advice!