If you can walk 10km a day and are in good aerobic shape you should do fine. The actually trekking is on mostly level ground with a few sections of steep hillsides – up and down. You won’t be carrying more than a light day pack with a jacket, water and snacks. However, it is the altitude that creates the main issues. That said, the better shape you are in, the more you will enjoy the overall experience. Altitude sickness is the main issue so it is important not to climb too quickly to give yourself enough time to acclimatise. Your guides know the best way to acclimatise and can spot any early signs of sickness to help you.