It was tough to ride for the Pony Express. Each rider had to weigh less than 125 pounds. Speed was the key. Most of the riders were teenage boys. They rode at a fast pace for up to 100 miles a day. If there were an emergency, one might have to ride 200 miles in a day. The ride could be rough and dangerous. Attacks by Native Americans were common. But in its time running, the Pony Express only lost one mail pouch.