Risked bad leg recklessly covering miles (7)
I believe the answer is:
gambled
'risked' is the definition.
('gamble' can be a synonym of 'risk')
'bad leg recklessly covering miles' is the wordplay.
'recklessly' is an anagram indicator.
'covering' is an insertion indicator.
'miles' becomes 'm' (common abbreviation).
'bad'+'leg'='badleg'
'badleg' anagrammed gives 'gabled'.
'gabled' placed around 'm' is 'GAMBLED'.
(Other definitions for gambled that I've seen before include "Speculated - took chances" , "Made a bet" , "Took a punt" , "Wagered" , "Took a chance" .)