Sports shoes (5)
(Other definitions for pumps that I've seen before include "Dancing shoes - may be manned!" , "Forces liquid to move; light shoes" , "Moves fluid or gas by pressure or suction" , "Plimsolls" , "needed by cyclists" .)
(Other definitions for trainers that I've seen before include "required to get the best out of racehorses" , "Sneakers" , "not Oxford types" , "Casual shoes" , "gym shoes" .)