Very Strenuous trekking grades is best described as Alpine and most strenuous, which require mountaineering skills and knowledge. The elevations range from 4000m to 6000m and approximately 7hours walking a day for the trekking in Nepal. It covers very remote areas, traveling over snow-covered passes at an altitude of up to 6000meters. You may need to axes and crampons to cross the pass when there is heavy snow