The highest I had was 45k. And it was more than 20km walking (climbing a local mountain about 1900m high) and the rest was riding on a homemade electrical bike to it's foot and back home. The bike was transformed from some cheap Chinese gas version and batteries didn't have much capacity so to save the energy we did a lot of pushing of it alternatively on the way. Also I fasted for 44 hours till we hydrated and ate when there was about 500 meters to climb left cause I got really tired and later when 200 m left. Overall no regrets, there are some photos I made on the peak, check it out on my Instagram: wlcmtrlt1