Sisyphus (1974)

If this short animation doesn't leave you feeling exhausted the I don't know what will. A man with almost perfect musculature has to roll a great big boulder up to the top of a pyramid of other great rocks - and judging by the energetic audio it's an all but Herculean task. Why? Well we're not told that here but your Janet & John book of Greek Mythology will tell you that he was a greedy king who broke the sacred rules of hospitality and was being eternally punished by Zeus. The animation is wonderfully simple illustrating the litheness of his body and the onerousness of his perpetual struggle with a fluidity that works well married with the increasingly breathless sound. I must have seen this as child as I'm sure it's the reason I avoid the gym!