The runs each day were hard with ascents of up 13000ft. The tracks were very technical often very narrow on the edge of cliffs. Stages 3 and onwards were at high altitude where breathing became very laboured.
Going up to Manaslu base camp was difficult with a steep ascent and over 4000m high. lots of the group suffered from altitude sickness and horses were needed to bring them back down.
The air was thin only 11% oxygen compared to 21% at sea level. Even sleeping at height made you puff. The whole experience has been humbling seeing such poverty that these people live in and they are still happy and have deep souls.