We shouldn’t have to walk around engaging our core and making muscles over the course of the day. The body is meant to have the right amount of muscular tone so the art of living and moving is unconscious and taken care of because we have the requisite strength to accomplish whatever physical tasks we undertake.
When someone comes to me to learn how to walk and is particularly weak I might tell them to engage their abdominal muscles for a short stroll in order to feel the benefit that core tone might bring them. But walking around that way all the time would be highly counter-productive.
This is the best argument I know for exercising.
A football player running downfield doesn’t think about making muscles to brace for impact; he spends hours in the weight room lifting weights and doing assorted other exercises in order to prepare for the pounding that his body is going to take.
Teaching yoga I am often imploring people to engage this and that to make their poses solid but ultimately balanced muscles accomplish their tasks because they are adequately developed to work correctly.
One of my first teachers told me that you should be able to do any pose and have a relaxing chat with someone at the same time. I have always loved that idea because having an easy conversation and making muscles simply don’t go together.
When it comes to the exercises we choose to do there should be a specific attempt to only build the muscles we need to create a correct balance in our musculature. A boxer could make the argument that a thousand sit-ups a day will make his abdominal muscles hard enough to withstand the hardest punch. That makes perfect sense to me but I don’t see many other reasons to do tons of sit-ups.
This gets to the heart of my walking program. I think we tend towards common imbalances in our muscle tone. Short in the back and long in the front. Weak in the inner thighs, and strong on the outer thighs.
The goal is to build balanced muscle tone that serves us each and every day so that the idea of making muscles to realize something physical is not necessary.