He should be fit to revise the tale (7)
I believe the answer is:
athlete
'he should be fit' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'revise the tale' is the wordplay.
'revise' is an anagram indicator.
'the'+'tale'='thetale'
'thetale' with letters rearranged gives 'ATHLETE'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for athlete that I've seen before include "One may run" , "Holmes, perhaps" , "Olympic participant" , "Competitive runner, e.g." , "One trained to compete in sports" .)