Brokkr/Loki - In norse mythology, Loki bet his head to create treasures for gods between dwarves (Eitri & Brokkr). The dwarves were to compete to create precious treasurers. The winner was to get Loki's head. Sons of Ivaldi created Gungir-Odin's spear and Skioblanoir- Freyja's boat.
To create more precious than the above and to slice Loki's head Eitri and Brokkr diligently engaged in creating Draupnir-Odin's ring and Mjollnir-Thor's hammer.
Loki to avoid the win and in the fear of losing his head, turned to a fly and bit Brokkr on arm, neck, and eyelids.
Brokkr endured all the pain and suffering and blood and continued his blow except a short halt when his brother Eitri was making those invaluable treasures.
The dwarves finally won the bet.
Karnan/Indra - In Mahabharatha, the antagonist Karna disguised himself as a Brahmin to learn cavalry and archery tricks from divine guru Parasuram. Parasuram swore not to teach Kshatriyas. One day Karnan offered his lap as pillow to his guru's siesta. While Parasuram was wide asleep, a bee stung and bore a hole in Karnan's thigh, the bee was none other than Lord Indra(Hindu Zeus).
Lord Indra to prevent Karnan from learning the tricks, disguised himself as a bee and stung him. Karnan endured all the pain and blood and made sure that his Guru's sleep wasnt disturbed.
He was very much devoted and loyal to his guru. The blood disturbed the sleep and Parasuram after waking up immediately cursed his star pupil that he would forget all the spells(mantras) in time of need though he endured that agony only not to disturb his teacher's sleep. And Indra won the bet and his mission was accomplished.
Parasuram cursed him saying that Karnan cheated him and Karnan wasnt a Brahmin because only a Kshatriya could be so brave and endure so much pain and suffering.
Brahmins are vegetarians. There is no place in sports and war for vegans :)
Moral of the story : Want to become a nerd/geek, eat your veggies; want to become a athlete/warrior, eat your meat. ;)
Check more comparison mythology stories here