Enters race without water and becomes exhausted (4,3)

I believe the answer is:

runs dry

'becomes exhausted' is the definition.
(to run dry is to run out having been exhausted)

'enters race without water' is the wordplay.
'enters race' becomes 'runs' (as in running in a political race).
'without water' becomes 'dry'.
'runs'+'dry'='RUNS DRY'

'and' acts as a link.

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app