If an earthquake were to hit now, I wouldn't be able to run very far because I'm so full.
If there were an earthquake right now, I wouldn't be able to escape from the danger because I'm so stuffed.
ーIf an earthquake were to hit now, I wouldn't be able to run very far because I'm so full.
「もし今地震が起こったら、お腹がいっぱいすぎてあまり遠くまで走れないだろう」
wouldn't be able to run very far で「あまり遠くまで走れないだろう」
full で「お腹がいっぱいの・満腹の」
ーIf there were an earthquake right now, I wouldn't be able to escape from the danger because I'm so stuffed.
「今地震が起きたら、お腹が満腹すぎて危険から逃げられないだろう」
earthquake で「地震」
to escape from .. で「…から逃げる」
stuffed で「満腹して」
ご参考まで！
If an earthquake happened now, I wouldn't be able to run.
「もし今地震が起きたら走れない」というフレーズを英語で言う場合、"If an earthquake happened now, I wouldn't be able to run." が適切です。"If an earthquake happened now" は「もし今地震が起きたら」、"I wouldn't be able to run" は「走れないだろう」という意味です。
おなかいっぱいで苦しい時に、少し冗談めいて言う場合、次のように表現できます：
"I'm so full, if an earthquake happened now, I wouldn't be able to run!"
カナダ 
アメリカ合衆国 
