This five-day rim-to-rim traversal might pose a challenge even to avid adventurers. As you’ll be hiking for 8-12 miles (13 to 19 km) per day for several days in a row, you must be in great shape. Keep in mind that you’ll also be carrying a +35 lbs (+15 kg) backpack, doing up to 5,000 ft (1,524 m) of vertical ascent per day. The terrain can be rough and very steep at times, so good physical fitness is paramount. Due to the significant elevation changes, you should also prepare for extreme temperature swings and wildly varying conditions on the trail.