Demi Lovato isn’t taking haters lightly. She lashed out at critics on her Twitter over the weekend, who gave her not-so-nice comments about her music and her weight.

“Haters can only bother you if you aren’t doing anything to prove them wrong,” Demi wrote. “I can’t sing? I’m singing on the treadmill and practicing my a—off. You think I’m fat? I’m already in the gym!!!! You think I’m irrelevant? WATCH THA F—K OUT… 2014 I’m GOING IN with my music and touring!!!!!! Nobody’s gonna stop my grind... LET’S DO THIS LOVATICS!!!!!! #PUMPED.”

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Damn, Demi! She didn’t hold anything back. And is anyone else feeling super motivated after reading that? In case she ever gets sick of entertainment, motivational speaker could be in Demi’s future.

She continued, “It’s not about looking in shape, it’s about being emotionally and physically in shape from the INSIDE out… #ScrewNewYearsImStartingNOW… 2014 = health, fitness, strength & MUSIC.”

2014 will definitely be a big year for Demi. While she may be leaving The X-Factor to focus on her music, she’ll be hitting the road with Fifth Harmony and Little Mix for her Neon Lights tour!

How do you think Demi handled her haters?