Former X Factor judge Demi Lovato had a few words to say to her haters via Twitter.

"Haters can only bother you if you aren't doing anything to prove them wrong," she wrote on Dec. 27. "I can't sing? I'm singing on the treadmill and practicing my ass off. You think I'm fat? I'm already in the gym!!!!! You think I'm irrelevant? WATCH THA F*** OUT."

The Heart Attack singer went on to say that in the upcoming year she will focus mainly on her music career.

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"2014 I'm GOING IN with my music and touring!!!!!!! Nobody's gonna stop my grind..... LET'S DO THIS LOVATICS!!!!!!" she wrote. "2014 = health, fitness, strength & MUSIC."

The 21-year-old also spoke about body image and tweeted, "It's not about looking in shape, it's about being emotionally and physically in shape from the INSIDE out."

Living up to her New Year's resolution, the star will be touring with the five ladies of Fifth Harmony - Lauren Jauregui, Camila Cabello, Ally Brooke, Dinah-Jane Hansen, Normani Hamilton - on her upcoming Neon Lights Tour, set to kick off in February.

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"You can expect a show that I've never put on before. I'm really excited," Lovato recently told MTV. "Other shows I've had all about the music but this time I want it to be about girl empowerment. I want it to be a huge party that everyone has fun at and leaves with an incredible experience."

Lovato revealed that she will also be working on some new tunes while on the road and said, "I'll definitely be writing every chance that I get."

View thew Neon Lights tour dates here.

Tags: Demi Lovato