"Swimmer"

This young swimmer from the Australian Olympic team manages to sneak his new girlfriend, a gorgeous Danish gymnast, into his room at the Olympic Village.
Once she's inside, he quickly switches out all the lights and they rapidly disrobe and leap onto his bed in a flurry of athletic achievement.
After about twenty minutes of wild sex they both collapse back on the bed in exhaustion. The girl looks admiringly across at the swimmer in the dim light. His beautifully-developed muscles, tanned skin and smooth-shaven scalp glisten with little beads of sweat as he lies beside her. She's really pleased to have met this guy.
At this point the swimmer slowly struggles up from the bed. He fumbles the lid off a bottle on the bedside table, pours himself a small shot in a glass and drinks it down in one gulp. Then he stands bolt upright, takes a deep breath and, in a surprisingly energetic motion, dives under the bed, climbing out the other side and beating his chest like a gorilla. Then he vaults back on top of the girl and commences a frantic repeat performance.
The Danish girl is very impressed with the gusto of this second encounter. Somehow the Aussie has completely recovered from his previous exhaustion!
After nearly half an hour of wild activity in every possible position, the gasping male swimmer again crawls out of bed and swallows another shot of the mysterious liquid. Once more he dives under the bed, emerges on the other side, beats his chest and commences to make love all over AGAIN.
The girl is just amazed and delighted as the action continues at the same blistering pace as before. In the darkness, she can't properly see what kind of tonic is causing these incredible transformations, but she sure likes the effect! More than an hour later, after another repeat of the strange drinking ritual on his part, and a whole string of ecstatic multiple orgasms on her part, the Danish girl is now feeling rather faint herself.
"Just a minute, big boy," she whispers to the panting bald-headed Aussie, "I think I need to try some of your tonic!" She rises unsteadily and pours a small shot of the liquid. She braces herself for some sort of medicinal effect, but actually it just tastes like Coca-Cola. Then she stands up straight, takes a deep breath and dives under the bed - only to smash straight into the three other exhausted members of the Australian relay team.