I love looooong story jokes so here goes one of my favorites, sweetened a bit for the internet... but it's long so bear with it.
A grossly obese man is told by his doctor that he must lose an incredible amount of weight as soon as possible, or face severe health related issues, though no program has ever worked. On his way home, he spies a road-side sign reading "Miracle weight loss program! Lose 10, 20, or even 50 lbs in ONE WEEK GUARANTEED!" Desperate and depressed he writes the number down.
When he arrived at his home, he calls the number, to which the receptionist asks what program he would like. He tells her he wants to try the 10lb in one week program just to try it out. The receptionist takes his information, then tells him "Be ready to exercise at 7am next monday."
That monday, he is awakened by a pounding on the door, he gathers some clothes and shambles down the stairs. When he opened the door he is greeted by a lovely blonde girl wearing nothing but walking shoes, a sign that reads "if you catch me, you can have me" and a smile. Out of shape as he is, it takes him a while to catch the lithe girl, even though she was merely walking, and intercourse ensues. (I tell it a bit differently in person, you can guess) Every day that week, she arrived at his house at 7am, and every day he caught her a little bit sooner.
After the week was over, he weighed himself, and indeed he had lost 10lbs. Excited he called up the number again and requested the 20lb program. The receptionist again told him "Be ready to exercise at 7am next monday." "I will be!" the man quipped happily.
That monday, he was ready at 7 to find a stunning brunette college hardbody wearing nothing but a pair of cross trainers, a sign reading "if you catch me, you can have me," and a smile. The man was in slightly better shape now, yet it took even longer to catch the lithe swift girl, but eventually he did, and intercourse ensued. Every morning at 7am that week she showed up, and every day he caught her a little sooner.
At the end of the week he weighed himself to find that he had indeed lost 20lbs.
Excited, he called up the number once more and requested the 50lb weight loss program. The receptionist balked, saying "That's only for extreme situations, sir." The man explained his situation and was giddy to hear the receptionist say "Alright, be ready to exercise at 7am next monday."
That monday he was so excited, he was ready to work out by 6:30 and eagerly awaited his trainer. When the knock on the door came, he sprang it open to find Richard Simmons wearing nothing but a pair of track spikes, a smile, and a sign saying "IF I CATCH YOU I CAN HAVE YOU!"
^_^