The Brokenwood Mysteries (2014) : 5x3

Cycling is very de rigour around the globe and no less in Brokenwood. When one such MAMIL, (Middle Aged Man In Lycra), Lester Nyman, reaches the top of a local mountain after a gruelling ride and suffers a massive coronary, it doesn't seem suspicious. But then Gina reveals his toxicology showed astronomical levels of caffeine in his system and Mike starts to look more closely.