But American Mixed Martial Artist Julie Kedzie hit back at the claims, saying she often had yellow bottoms on her feet but she "didn't juice EVER".
Kedzie said the surface of the Octagon right ring rubbing off on the feet, combined with it being cold, was the cause of the discolouration.
Kedzie said she would "scrub the sh*t" out of her feet after a bout because "they got yellow as hell".
But while the canvas may explain the yellow, others are asking about the purple discolouration.
The level of discolouration, especially coming immediately on the back of a brutal knockout, led to an argument that the UFC star was suffering from Raynaud's phenomenon.
Raynaud's disease causes some areas of the body - such as fingers and toes - to feel numb and cold in response to cold temperatures or stress. Smaller arteries that supply blood to the skin narrow, causing a purple colour. In most cases the condition is harmless, but in severe cases a loss of blood flow can permanently damage the tissue and even lead to gangrene.
Other theories circulating in cyberspace are:
- Circulation issues;
- UFC fighters apply a resin to their feet for grip, and it can develop a yellow tinge on the sole;
- Weight cutting and dehydration taking a toll on the body;
- Dirty floors; or
- The photograph just has a yellow hue.