If only doing something every so often invalidates it, then what about cycling - only pushing the pedals 90 times a minute? What are you doing the rest of the time you lazy so and so?
I've always felt that golf is a sport but cricket isn't, possibly irrational you might think but how can something that takes days to play and where they're just standing around doing naff all most of the time be a sport? They don't even 'run' to score runs, most of the time I would describe it as an 'amble'.
Golf is fairly unique however in being one of the few non-adversarial 'sports'. Even cycling racing is adversarial to a degree. Time trialling, however, obviously isn't.
What about walking to the next hole? More time as a % spent doing this than, say, freewheeling in cycling.
Yeah, so it's a linear scale, not a binary distinction. Where do you draw the line as to what percentage of the time you have to be doing something...
While we're at it, motor racing, indeed! How is that a sport any more than horse riding (for the rider).
The power comes from the engine, and the horse's legs, respectively - not the driver/rider.
I think the idea that motor racing requires fitness probably stems from the fact that when they take their helmet off they are sweaty, so people assume it must involve physical exertion, but they're not sweaty because they've been exercising they're sweaty because they've been cooped up in a hot cabin for ages.
Come to think of it, why are 'sports cars' so called? The drivers are probably less likely to be involved in sport than those of cars with sensible boot space.