I finished the Bellingham Bay Half Marathon in 3hrs 3min. I followed the training for wal/run pretty closely. I went out too fast was my only problem which caused my right knee to really hurt about half way thtough.
I took some ibuprofen from the medics and kept going mostly walking the last hour. I highly reccommend the active trainer as each day all I did was do what it told me to do. I used biking for crosstraining. Good Luck you can do it if I can at 57 years old my first Half!!