Currently having some minor issues with insurance and rehab's. Until they get it together I want to do exercisers at home so I don't rot away while waiting. I have a stationary bike I can pedal but no treadmill so I will have to walk outside. Don't  know where to start on walking. Walk until I'm out of breath with or without oxygen. Or shouldn't I go till I'm SOB. What goal should I aim for? Don't want to get down the block and can't make it back. I'm getting out of shape, I need to start.