The strenuous treks are more or less similar to the moderate plus treks in terms of the number of trekking hours per day. But the temperature during the strenuous treks can be as low as -15 degrees C. In addition, the Strenuous trips are much longer than the Moderate Plus treks. The strenuous trips are on average 13-20 days in length. Trekking in such cold climatic conditions and for such a long period of time requires you to have good level of physical fitness. Besides, you will also need mental toughness to complete these trips.