I call this variation of push ups, the “deployment push ups” method. I just finished reading an excellent book about the Marine Corps, called ‘One Bullet Away.’ During the initial push into Iraq, the author and then Lieutenant recounts the story of what his men did during “down time.”
He said one of his Marines would take out a deck of cards and pull one from the deck, randomly. The Marine would then do the number of push ups that corresponded to the number on the card.
According to the author, the Marine sweated through the deck, again and again.
Sounds like a good way to change things up if your routine gets boring and you need a day away from the gym!