silly question about walking

when i walk home from work, i try to hold in my abs & kind of work them.  im wondering if there is any point to this? would i burn calories a little more by doing this?  would i help to strength my core a little more? i can only do it up to 15 minutes before i have to rest my abs, so i must be doing something for them???  i usually walk at a fast enough pace for about 40 minutes, but i have to stop at lights to cross the street. im just curious.

it's not silly and yes it will help.  Anything you do that works muscles helps.  Yrs ago I read about 'isometric' exercises to do if you have to sit for long periods of time and it was about clenching and holding muscles, so you holding yours in will be a benefit.

correct. you body doesnt know why your muscles are contracting just the intensity they are contacting at. whether you are flexing your abs or doing a crunch it is the same thing but just to a differant degree of intensity.

thanks for the input. i will continue to try to do this more. maybe it'll help me with jogging as well.  i also do this when im on the elliptic trainer. i let go of the arm swings, lengthen my stride as much as i can while focusing on using my core. i put my hands on my abs to make sure i can feel them flex. seems to give them a good little work out, until my back gets a little sore. so far can only do it for maybe up to 5 minutes.

I don't know how many extra calories it will burn, but it will help your core and when the fat goes away you'll have the start of good looking muscles already there.  I know a lot of people who use stability balls at work instead of chairs just for the extra core work they provide just by sitting on your rear all day!!