ENG問題

first, this sentense is not that correct if you are writing ...
He uses a weighted sled that helps PUSHING/TO PUSH his abilities to the limit.
is better like you said ...
BUT IN NEWS HEADER ... the habbit is different.... THEY TRY TO HIGHLIGHT WITHOUT TENSES....
"PUSH HIS ABILITIES TO THE LIMIT" becomes a NOUN ... a PHRASE ... that act like a NOUN ...
so you should read ...
He uses a weighted sled that helps / "push his abilities to the limit".
A similar situation :
DROPPING GAS PRICE HELPS STOCK MARKET RALLY or
Retail rally helps push European stocks higher