3) Weighted Push ups
Nothing challenges the the whole body more than adding weight to your standard push up. Add a plate to your back or wear a weighted vest
Bring your hands underneath your shoulders. Line the thumbs up with your clavicle. Find a firm press through the hands into the floor. Maintain this connection and slowly lower yourself all the way down. Let your chest find the floor. Lift your hands up, set them down and press all the way back up. That's one rep. Repeat until your form is compromised. Add a weighted plate to your back for a challenge, or try it at an incline to modify.