Bike Anti-Porn - When Things Go Wrong

The history of dumb inventions is littered with examples of 4-limb cycle propulsion, all created by people who forgot to do their homework re. limiting factors in human powered vehicles. Since the limit is metabolic, and that limit can be exploited by either legs or arms, splitting it between both just adds mechanical losses without making any extra power available. Since I don't click on DM links, can somebody tell me whether this particular invention causes or prevents cancer?

*"Varibike looks like a regular bicycle, with traditional foot pedals, but additionally comes with a set of cranks that the rider turns with their arms to make it easier and faster when cycling"* <~ this line, epic.

I can't even find a word "cancer" on those page....