One of the key elements of training for long trips in high mountains is running – preferably in a hilly terrain. Sadly I live in a flat area myself.
Running is a sport that does not demand a lot of equipment or special facilities or a team – yet it put a greater stress on your body compared to cycling or swimming. Because of that it one of the better forms of preparation for extended effort in the mountains.
There are many training plans in the Internet that you can find. I started few years ago with C25k (couch to 5k). All you need is a bit of patience and after few weeks you can enjoy running. Nowadays I run long distances every weekend in nearby parks. What are your suggestions? How do you train?