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.