Kylie Jenner’s BFF Anastasia ‘Stassie’ Karanikolaou shows off her extremely trim waist in a skintight workout outfit on her way to a gym

On Thursday, Anastasia Karanikolaou was seen heading to a fitness class in West Hollywood.

Anastasia ‘Stassie’ Karanikolaou shows off her extremely trim waist in a skintight training outfit

The 25-year-old internet sensation showed off her toned arms and flat tummy in the GLOWMODE workout gear she wore while basking in the California heat.

The model, who has been promoting her latest project with the Cupshe brand, wore a dark blue ensemble.

Her sports bra top was designed to show off her ample bust with wide straps and a plunging neckline.

She also wore long white socks, grey and blue sneakers, and a pair of leggings.

As Anastasia headed to the gym, she basked in the sunny California weather.

In anticipation of her workout, she put her long brown hair in a high ponytail.

The model wore a set of silver stud earrings and a pair of rectangular-framed sunglasses to complement her bare face.

She had the car keys in one of her unmanicured hands and a small black purse slung over her shoulder.

Her recent spring ad with swimwear and apparel label Cupshe coincides with her visit to the gym.

Kylie Jenner’s longtime best friend is overjoyed to be collaborating with the company.

‘I’ve always loved swimwear and trying new styles, so when I had the opportunity to partner with Cupshe, I wanted to really focus on the fit and versatility of styles,’ she shared.

‘The Cupshe team has been so great in this partnership, they allowed me to take artistic direction and introduce more variety into the collection so that the selections are truly pieces I would wear or my friends would wear.’

She continued by saying the brand has always had her undying loyalty.

‘Cupshe’s support and variety is what draws me most to the brand,’

‘There aren’t a ton of cute swimwear brands that offer different levels of coverage and quality that Cupshe does,’ she added.

The stunning woman then identified her favorite item.

‘My favorite piece from our collection is definitely the zebra print swimsuit. I love how the pattern is so dimensional but also very chic and simple,’

She added that she felt the line reflected her own sense of flair.

‘My Cupshe collection is versatile, much like my own style,’ noted the star.

‘There are pieces that are super classic and simple; and ones that are bolder and more outgoing. There really is a suit for any type of mood you are in,’ she shared.