Lofty jerks compete in field events, perhaps (4,5)

'lofty jerks compete in field events perhaps' is the definition.
I can't tell whether this definition defines the answer.

'lofty jerks compete in field events' is the wordplay.
I cannot quite understand how this works, but
'lofty' could be 'high' (similar in meaning) and 'high' is found in the answer.
'events' could be 'jumps' (jump is a kind of event) and 'jumps' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?