Ok after mastering the plank it time to step things up with the press up.
For this I want you to us all the skills learned from the plank; but this time with your arms straight and at shoulder width distance. Lower the upper body to the floor by flexing at the elbow, but keep them tucked in, until your chest is roughly a fists distance away from the floor, then press yourself back up until arms straighten (not locked). Repeat as many times as you can manage then try to beat yourself each time you come back to them. If you find it too hard you can do them from on your knees but keep the hips inline with your body and pivot on the knees.
Stay fresh and healthy!