Are you still using a 40 year old training schedule??? 40 years ago there weren't as many half and full marathons as there are now. Running was a competitive sport, but now it is more FUN and health training. Back then almost everyone that ran a marathon was under or close to 4 hours. Now we have many that take up to 8 hours to walk or run a marathon. Those schedules had Novice, Internediate and Advanced. Novice was designed for those that ran about a 9 minute pace. In this day and age you need a schedule that is designed for you. You can start with a very scaled back schedule and change it as you advance in ability. Do not over-train. You may need to do some strengthening exercises before you start walking or running. Running is not just placing one foot in front of another. Start slow, plan ahead, use a schedule that is designed for you and plan ahead to long and healthy love of running and/or walking. Runners Live Longer
Stay injury free.