Now onto your last 10!. So what is the last 10%. In the physical realm of the mountain climb it literally is the last 10 up the mountain. Your body is exhausted. Maybe your are enduring muscle cramps, dehydration, exhaustion or all of those. the last 10% while only a small percentage seems to be the most difficult. Why? In the climbing scenario it probably is a culmination of the 90% that you have already climbed that has provided a lot of wear and tear on your body.