When Rainsford and his friend are discussing the island at the beginning of the story, his friend says that it is four miles to the island but impossible to see in the dark. Rainsford falls off shortly afterward and then swims the four miles to the island. When he gets to the island, he hears the waves crashing against the jagged cliffs. He climbs those jagged cliffs, hand over hand, until he reaches the top. He is exhausted at the end, but obviously very fit.
General Zaroff challenges him to the hunt and gives Rainsford a head start. He fights his way through the jungle for two hours before he decides that he shouldn't leave a straight path to follow. Then he walks in circles overlapping each path to try to confuse Zaroff. Throughout the hunt he climbs a lot of trees. Each of this tricks also take great strength. He digs the Burmese tiger pit on his own and sharpens all those stakes. He bends trees, and climbs trees to set things ups.
When he reaches the cove, he has to dive 20 feet down to the crashing waves and then swim to the chateau. The story tells you that Zaroff rested that evening and then retired to bed. Rainsford was waiting for him. After swimming across the cove to the chateau, Rainsford still had enough strength in him to challenge Zaroff to a sword fight and WIN!!!