Indoor facilities have to stand up to constant hard use, and they have to keep performing day in day out.
For indoor use, especially training in smaller areas with lots of starts and stops, safety is all about selecting the proper turf system for rotational resistance, with good impact and shock attenuation characteristics.
Turf and infill options will vary depending on the intended use of your indoor facility. Consistency of the playing surface over the duration of the system life is paramount.
Heavy indoor use needs a heavy-duty turf system to match.