Down-to-earth points helpful to athletes (6)
I believe the answer is:
spikes
'helpful to athletes' is the definition.
I can't judge whether this defines the answer.
'down-to-earth points' is the wordplay.
'down-to-earth' becomes 's' (I can't justify this - if you can you should give a lot more credence to this answer).
'points' becomes 'pikes' (pike is a kind of point).
's'+'pikes'='SPIKES'
Can you help me to learn more?
(Other definitions for spikes that I've seen before include "Makes (a gun) useless" , "Prongs" , "Sharp points on athletes' shoes" , "Running shoes" .)