I am farely confident that it would be hockey in the NHL, they have 3-4 officials on the ice at the same time as a max of 11 players. Nope. It would have to be Tennis. Maximum of 4 players at one time, with an umpire assigned to each line in an ATP match. Ah yes, that's right. I forgot about tennis. Good work.
The UK sport with the most participants is angling
Just about every sport there is
Speed skiing the flying kilometer speeds up to 156mph the current world record
Fencers are participants in the sport of fencing, a sport that uses swords.
sport officials are people such as the refferies and umpires and linesmen. they are impartial and do have first aid training.