The classic exercise, the full version.

Kneel on the gym mat, and walk your hands forward - straight arms - until they are at a distance from your feet which will place them level with your chest when you lower your body towards the floor, and just wider than shoulder - apart. Your head should then project beyond your hands when you lower your body towards the floor.

Raise your body so that it is supported on your hands - straight arms - and your toes, keeping it rigid from shoulders to toes, and maintaining the Neutral Spine Position. Lower your body to the floor by bending your elbows, hold for a second and then push your body back up, straightening your arms, making sure you keep your body rigid and maintaining your Neutral Spine Position. Don’t over extend with your arms and shoulder blades when you push up

Do not let your head or body touch the floor until the exercise is over.