After all these years, the push-up and its variations are still one of the very best exercises available to those seeking to enhance their muscular fitness. Forget all the high tech, expensive exercise equipment which is marketed to you on the late night infomercials. Push-ups are FREE and only require about 12 square feet of floor space...and they deliver great results for people of all fitness levels (from the rank beginner to the very advanced fitness enthusiast).
Push-ups stimulate several muscles of the body simultaneously. While they provide a high degree of direct work to the upper body pressing muscles-the chest, front shoulders and triceps-they also provide a great deal of indirect work for the core muscles of the hips and midsection, as well as the lats. Plus, push-ups are a great exercise to develop scapula stablity and they can prevent shoulder injuries provided they are performed properly (elbows kept slightly tucked into the torso at about 45-60 degrees...avoid flaring the elbows out excessively). Push-ups are a closed chain exercise, and are much safer than barbell, machine or dumbbell chest press/bench press exercises which work the same muscle groups.
I program the push-up and its variations into the routines of ALL of my private clients, regardless of current fitness level. For those of you who think push-ups are a "beginner" exercise or "too easy", I encourage you to make sure you are doing the movement correctly and under control. If you are, try some of the more advanced push-up variations in the playlist linked to below for added difficulty (note, the woman in many of these videos is 50 years old!):