Force yourself to start slow and finish sooner than you like.
Tell yourself you deserve the punishment for getting out of shape.
The first week is the only hurdle. Tack a note on the fridge: it will get better. GE guarantees it does.
There are four paths to advance in walking called resistances: distance, frequency, speed and weight. You may toy with these or take my advice from having used walking/hiking a half-dozen times to cure various maladies.
Start with slow blocks of time spaced frequently throughout the day.
After one week increase the duration of each walk while reducing the number.
Beginning the second week don a knapsack with five pounds of stones or water.
Daily increase the weight 6-ounces.
In one month you will look back at your tracks and marvel in good health.