The majority of people in the world cannot complete a half marathon, let alone under two hours. I was pleased to train enough that I managed under three. You're doing great!
half marathon is ~20 KM its pretty sad that a large percentage of people cant do that. One can simply walk that much distance wihtout any prior training.
You can walk it in under 4 hours. I can do it, but I can't run that much, my calves are just not trained for aerobic workloads. I don't run normally, I walk or cycle, but do not run.
