Since I've been a runner for over 50 years, and am a current high school track and cross country coach, I feel qualified to comment. Most people deciding "to get back in shape" start running way too fast. They become exhausted, winded, tired, and sore. It's an unpleasant feeling, so the training period is short lived. I tell people to start running very gently, a comfortable pace, where you can carry on a conversation with a partner without being out of breath. It might not be faster than a brisk walk. Do that for 15 minutes and try to increase by 10% a week. This is effective for conditioning, cardiovascular health, weight control, and just plain feeling good. Doing this, many adults become pretty fit and enjoy the running much more. You simply don't have to train like you're going to the olympics and exhaust yourselves.