To trek you do not need to be a super athlete nor a mountaineer but a few weeks of training, prior to arriving in Nepal, will enhance your experience. It will not be more enjoyable spending the trip of a lifetime struggling to walk the trails every day when a little sensible preparation before you arrive would make the trails so much more rewarding.
So it is important to be in good physical condition before you start your trek and the best way is to do a lot of walking. Try to spend an hour a day on the road. Walk upstairs rather than take a lift, if possible, walk or cycle when you would normally drive or ride a bus, take the dog for a walk. Jogging and aerobics will also hand. Running a few miles most days is probably the best single physical activity, which will hand. It doesn't have to be too complicated. While you are training you can also be breaking in those new trekking boats that may otherwise give you blisters on the first day out on the trail. Those who are planning to climb one of the trekking peaks need to be physically very fit.
Please also be mentally prepared for Nepal. It will be good if you try to find out as much as possible about Nepal's customs especially about the particular trek that you have planned before arriving. I am always happy to give you information with updated facts.
