Kristin Cavallari works out early in tank top and leggings before signing copies of new cookbook

Kristin Cavallari works out early in tank top and leggings before signing copies of new cookbook

Kristin Cavallari shared an early morning workout selfie Tuesday before taking on a book signing for new gluten-free cookbook.

The 33-year-old reality star posted a photo on her Instagram Stories of herself in a grey tank top that showed her toned arms and a bit of her flat stomach while working out at 6:14 am in a gym.

Kristin completed her workout outfit with matching grey leggings and black-and-white trainers.

Early workout: Kristin Cavallari shared a selfie Tuesday from an early morning workout session on social media

She glowed and glistened from her exercise session in the selfie with her blonde hair pulled back into a ponytail.

Kristin also noted in the caption that her lifestyle brand Uncommon James will launch its spring/summer campaign in one week.

The Very Cavallari star also posted an Instagram photo wearing a white low-cut top, dark blue blazer and blue skinny jeans.

Kristin had her her in a ponytail and also accessorized with earrings as she stood behind a long table filled with open books.

Book signing: The 33-year-old reality star also shared a photo on Instagram of herself about to sign copies of her new cookbook True Comfort

Book signing: The 33-year-old reality star also shared a photo on Instagram of herself about to sign copies of her new cookbook True Comfort

Hair up: The Very Cavallari star also posted a photo of her blonde ponytail

Hair up: The Very Cavallari star also posted a photo of her blonde ponytail

Coffee mug: The Laguna Beach star also showed off an inspirational coffee mug

Coffee mug: The Laguna Beach star also showed off an inspirational coffee mug

‘Let the signing begin #TrueComfort,’ Kristin wrote in the caption for her roughly 4.1 million followers on Instagram.

Kristen’s new gluten-free cookbook True Comfort will be released September 29 by Rodale Books.

The 272-page cookbook features more than 100 recipes free of gluten and refined sugar for healthy comfort foods.

Coming soon: Kristen's new gluten-free cookbook True Comfort will be released September 29 by Rodale Books

Coming soon: Kristen’s new gluten-free cookbook True Comfort will be released September 29 by Rodale Books

Kristin also posted photos on Instagram showing off her hairstyle and a coffee mug that read ‘Make Your Own Magic’.

The Hills star has children Camden, eight, Jaxon, six, and Saylor, four, with estranged husband Jay Cutler, 37.

Kristin and Jay got married in June 2013 in Nashville, Tennessee, and announced in April that they were getting a divorce.

Former couple: Kristin has children Camden, eight, Jaxon, six, and Saylor, four, with estranged husband Jay Cutler, 37, shown together in April 2017 in West Hollywood, California

Former couple: Kristin has children Camden, eight, Jaxon, six, and Saylor, four, with estranged husband Jay Cutler, 37, shown together in April 2017 in West Hollywood, California