M & M Mars introduced the Marathon candy in 1975 with an interesting ad campaign starring a hero named Marathon John, portrayed by actor Patrick Wayne. Unfortunately, the product didn't last long, as for all intents & purposes it was Mars' answer to the longer-running, more established Bit O'Honey.
D. Heine serves up Marathon John vs. Quick Claude.
A few years later, Mars would revive the Marathon name, but as an standard size candy bar, billed as an energy bar as part of the Snickers brand. Unfortunately, that, too, did a quick fade. Sometimes, things just ain't meant to be.