When I ask clients to incorporate just a bit more exercise into their day, I often hear one of these: "I don't have time to do that" or "Are you kidding me? I can hardly get out of the door on time" or, "get up 20 minutes earlier to walk? are you nuts"? "I'm too busy to do that". "It's too cold and rainy"...
Ok so you get my point
The bigger picture here is that until a health habit is formed, it can sound overwhelming. Once the benefit of just a 20 minute walk kicks in, it's much for doable. I think writing out a plan everyday and looking at how many minutes are wasted in a day is eye opening.
I also think that most people will realize that the world won't end because they have taken a 20 minute walk, and that it truly is ok to step outside and do something everyday to increase longevity.