Linda is delighted when she heads out one morning, and watches a fine figure of a man jogging by. She starts deliberately leaving home as he jogs past, and exercising in the front garden. It does the trick, he introduces himself. Karl is in training for a 100 mile triathlon. Linda embarks on a fitness regime to try and impress him.

Darren and Jimmy won't admit to being unfit, so end up roped into attending the circuit training sessions Karl runs. Of course they are rubbish, but Jimmy refuses to give up and let Karl believe he's better than him. Everything is going perfectly until Linda tries to lure Karl into the bedroom. He tells her he can't risk losing his competitive edge.

Michelle lets slip to Jimmy and Darren that there's been no bedroom action. The two delight in teasing Karl while he tries to coax them towards fitness. Meanwhile Frank teases Linda about all the things she misses out on because of her new regime. Finally the triathlon is over, and Linda lures superfit Karl under