The Pass the Block exercise works your rectus abdominis and transversus abdominis muscles.
The next exercise is called block switch. You're gonna have a block between the hems. Important part to note is that your belly button constantly presses down into the floor and you'll see. So take the block between the hands and then squeeze it between the feet. You reach the body long. [unk] and grab for the block and reaching up an overhead. That's one rep. Just like that. Here's 2, 3.