Mara’s a fighter

She snorted a quick laugh. "You remember me when we first met? You remember how I was?"
"Trying to kill me to comply with the Emperor's last command."
"Right. Luke, I'm a fighter. I've always been a fighter. The few times when I have been at leisure, I've been miserable. I want challenges, I crave them. As nice and peaceful as it was up north here, it lulled me, dulled me, took the edge off. Anakin made it so I had no needs, and Dantooine- before the Yuuzhan Vong- had nothing more dangerous than big thorns to worry about. I was wasting away, trying to conserve my strength, all the while turning away from the means I'd used in the past to tap the Force."
Mara gazed up into Luke's eyes, and he could feel their personal bond and connection strengthening. He got past the fatigue to the image of Mara that existed deep in the woman's psyche. This Mara, strong of limb and sharp of eye, wore armor, sported blasters, and looked like someone who could take a Death Star apart from the inside out.
"That's who I am, Luke. When Anakin and I had to run, I felt exhausted, physically, but I was stronger in the Force. I was able to repair some of the damage the disease had done. I realized that's the most insidious nature of the disease. Many people, when they become sick, retreat to their childhood and being helpless. They abandon who they have become and their place in the web that is the Force, then disease severs those final connections and they die.”
Luke watched for a moment, then frowned. "So you're telling me that no matter how tired you are, that letting you fight against the Yuuzhan Vong will make you stronger."
"As long as I'm fighting, I'm not dying."
He shivered. "I'm not sure I like the cure, but I like the disease less."
"You'll let me fight?"