That’s right, abs too! As we all know, push ups are an excellent exercise that you can do just about anywhere. They work the chest and triceps and to a lesser extent, the shoulders. Put your feet up on an exercise ball or a chair and you can do inclines to focus more on the upper chest. Move your hands closer together and you have yourself a very challenging triceps exercise. But what most people don’t realize is that they work the abs also.
You see, the abs are required to keep the body stabilized when you assume the push up position and the movement puts extra stress on the muscle as you complete each rep. Many cutting-edge exercise physiologists and strength coaches are now recommending that the most effective way to work the abs is using movements that don’t involve too much movement of the abs like crunches but to instead use movements like “the plank”, which stimulate the abdominal muscles without contracting them. It’s also becoming clear that crunches and sit ups may increase the risk of back problems.
You can confirm this effect of push ups if you haven’t done them in a while – do about 4 sets to failure with a minute or two between sets and the next day your abs will most likely feel a bit sore (depending upon what level of conditioning you’re in). So if you haven’t been doing push ups as part of your chest routine, you now have one more reason to add them in!
source: tropicanafitness.com