Also worried about large and medium race (6)
I believe the answer is:
slalom
'race' is the definition.
('slalom' means to move in a zigzag)
'also worried about large and medium' is the wordplay.
'worried' is an anagram indicator (worry can mean to interfere with or disturb).
'about' means one lot of letters goes inside another.
'large' becomes 'L' (eg in clothes sizes).
'and' is a charade indicator (letters next to each other).
'medium' becomes 'm' (as in UK clothing sizes).
'also' anagrammed gives 'salo'.
'salo' enclosing 'l' is 'slalo'.
'slalo'+'m'='SLALOM'
(Other definitions for slalom that I've seen before include "Downhill race over a winding course on skis" , "Downhill ski event" , "Downhill ski-race over a winding course" , "Skiers' obstacle race" , "Winding ski-run" .)