These are typically done with core sliders, but an old magazine or the lid from a Tupperware container will work too.
Slider Reaching Push-Up
Sliding out to a flye on one side is a good way to hit your chest and make your regular push-ups harder. There's also an anti-rotational component with these, so they're a good core exercise.
- Set up for a regular push-up with one hand on your makeshift slider.
- Drop into your push-up, sliding one hand out into a flye at the same time. Press back up while sliding back in.
- The slide should be smooth. If it isn't, you've likely gone wider than you can handle, or need something that slides with less friction.
- Remember, push-ups are moving planks. Keep your lumbar from overextending and your hips from rotating.