Ailin Perez walked on the scale shaking and crying in a scary UFC weigh-in scene

Weight cutting is undoubtedly a dirtier side of MMA, as fighters often starve themselves and drain all fluids from their bodies in order to reach a set weight limit.

Perez weighed 136.5 pounds, just half a pound less than her peak weight of 136 pounds.

Their bodies likely responded to the lack of nutrition by sweating out the remaining fluid, with fighters often going without food or drink for 24 hours before the weigh-in.

She also had to mentally grapple with the realization that she had failed and may need to continue her weight loss journey. Either she or her trainers decided it wasn't worth continuing the brutal weight loss, and she ended up losing 20 percent of her salary to Zheleznyakova.

The fight is still expected to go ahead as planned.

If a fighter has only lost half a pound, he will usually jump into the sauna, if available, and try to lose the last half pound if there is still sweat in it.

This time Perez didn't bother, perhaps because he feared she would cause severe damage to her organs if she tried again.

Now she is preparing for a cage fight in Paris as the world No. 15 bantamweight is scheduled to compete in the preliminary round tournament on Saturday.

If she wins, she'll probably shake her butt again, as she's known to do in celebration.