Most foxes don't take much catching and neither do deer on the lamp especialy after they have half of there energy sapped by being chased around afield by a motor....well they never used to anyway..now on the other if you are out on foot for 6/7hr's getting 50/60/70 and so on bunnie's aswell as missing load's more and the other odd bit's and bob's you will hopefully understand that the dog is running vertualy all night long with only a short break for a cuppa and a sarnie..now if that's easy and it don't get the dog to peak fitness fook know's what will..