Former 'Beverly Hills, 90210' actress Shannen Doherty busted out her best dance moves at the gym on Thursday, fighting through the nausea from her chemotherapy treatment the day before.

The actress, who was diagnosed with breast cancer over the summer, explained in an Instagram post that she wanted to fight through her illness to "get the blood flowing."

Another post shows her dancing. "Shaking your booty is hard work," she wrote. "Yes, I was tired, yes, I wanted to be in bed but I went and moved and felt way better. Any exercise during illness is good." The post includes the hashtags #fightlikeagirl, #BeastMode and #Warrior.