This is a design with the message Put Up or Shut Up, meaning that you either do something, take action rather than just talk and complain.
I created this during a time when I had lots of ideas and things that I wanted to do. So rather than just think about it and leave it, I made a reminder to myself to take action.
「Push Up or Shut Up」、つまり「口だけ言うじゃなく、行動しろ」という意味です。
Buy the T-shirt (Japan) http://ttrinity.jp/shop/yudesigns/design/1475561