Northerner's circuit training — learn to carry dumb-bells at first (9)
I believe the answer is:
laplander
'northerner's' is the definition.
(I've seen this before)
'circuit training learn to carry dumb-bells at first' is the wordplay.
I cannot quite see how this works, but
'circuit' could be 'lap' (synonyms) and 'lap' is found within the answer.
'first' could be 'a' (first letter of the alphabet) and 'a' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for laplander that I've seen before include "one in the far north" , "Northerner?" , "North European" , "What falls easily to one" , "Santa's compatriot?" .)