School programs usually start to run Conditioning and/or Open Gym sessions a few weeks prior to each season start.
http://www.ohsaa.org/sports/rglts/GenSportsReg12-13.pdf
There are different regulations for each. Coaches may have more 'control' for a Conditioning (see 8.0 Physical Fitness Program) session but everything is to stay no sport specific.
If they are using sports related equipment, drills or even some sort of pick-up game then it is classified as an (9. Open Gym). At this point coaches are there for supervision (think recess monitor) and should
not be instructing/coaching. They can participate (ie play along - 9.1.10) in whatever activities the
players decide they want to do with this time.
The above represent my interpretation based on what I have seen with both my DDs growing up playing different sports. When in double ask your AD since it is his responsibility to oversee/enforce. It will probably be the easiest question/concern he will have to address that day.