The 32-year-old recently shared a series of videos from her one-arm workouts, but some critics could only focus on her outfit or, in their opinion, lack of it.
While many fans were suitably impressed with her persistence sans limb, the star also received a number of comments about her bra-less boobs.
"But you could wear a bra!" one wrote.
"Don't be jealous. It's not flattering,” Kaley replied.
"FYI because of my shoulder, I can only get certain bras over my head NOT THAT IT’S ANYONE'S BUSINESS," she elaborated in a later post.
The star also shared some words of encouragement for her followers who might be struggling to stick with a fitness kick.
"Alright there you have it, no excuses," she said. "Injured or not you can still have a badass workout. I'm absolutely dead and ready to eat something. That was frickin' awesome."
Kaley isn't afraid to admit that she has to work hard to stay fit.
"Bottom line is, you know, I’m not 21 anymore," she previously told Women's Health. "It used to be so easy, I didn’t have to do as much. Now, it’s part of my day — working out is part of my day, eating right is part of my day."