Let me start off by saying that I think walking is really a great way to start being more active, but I'm wondering how much it helps for moderately active people.
I've been walking to work (~4 miles there and back) for a month and I saw some results. Now, I've taken to doing fairly vigorous cardio on a stair master and rowing machine roughly 4-6 days a week.
Will walking still have any benefits? I'm not really challenged by walking, heck, my fiance and I walked around yesterday for 50 minutes and I barely noticed the time go by...I cant really -jog- between jobs or on my break because I have to be none sweaty and presentable, so should I even bother walking about?
I also walk whenever I can to/from work - I don't use this as my exercise for the day like some others might as I agree that's it's not nearly strenuous enough, however, I KNOW that walking to work [3.5 miles both ways] burns more calories than sitting on the subway. So therefore, it definitely does have a benefit. You will always burn more calories walking then sitting or standing.
The only way it would be bad or not worth it would be if you went from a more strenuous activity to walking which would burn less cals - like from running to walking...
My friends father went walking every night for about 5/6 months and lost around 2 stone (28 lbs). He told me his walk was about 5 miles. I'm sure it was mixed in with healthy eating also. In general, he is a very healthy man. I do think it makes a different but you need to be doing it a good pace to see results. However, a poster above me was correct and I agree with what they said about even walking at a slow pace to work or that is better than sitting down on public transport because at least you're on the move. I also think that even though you are doing something else, it would be worth it still walking! The more exercise, the better if you ask me.
If you stop walking, then try it again, you'll realize the impact it has. Early on walking was my exercise of choice. 4-6 mile walks at least 3 days a week. Then I moved on to what felt like more efficient workouts: jogging, ellipticle, bike, body pump, etc. So one day I decide to go for a 4 mile walk, and I was sore after! It works different muscles from the other exercises and I had been neglecting those muscles.