回到拳館看見一個熟悉的舊沙包...

When I returned my martial art  training center, I saw an familiar old  punching bag... 

開始不斷重擊著老舊的沙包...

I started to punch the old punching bag very hardly...

用不斷踢打的重擊聲譜出屬於自己的樂章...

I punched and kicked the puching bag unceasingly to make the noise into my own music movement...

老舊的沙包有如一塊磨刀的寶石...

An old punching bag is jut like a knife sharpener... 

將慢慢鋒利我那生了鏽的拳頭與踢技...

And it will sharpen my fist and kicking skills little by little...

從前為了和人幹架而鍛鍊...

I used to train myself for fighting...

現在是則是為了找回一點衝勁而鍛鍊...

But now I train myself for to be aggressive...