You’ve probably seen her before, all over your TikTok feed. She likely woke up before sunrise in a tastefully but minimally decorated apartment. By 7 am, she’s putting on a matching workout set and slicking her hair back into a sleek bun. After her workout, which was probably pilates or a weight-lifting session, she contorts her body into the perfect pose for the mandatory post-workout mirror selfie. She often proclaims to be “that girl,” and her online aesthetic is a moment of fleeting perfection. She’s stunning. She’s fit. She has the look.

“That girl” hasn’t strayed far from its original status as a way to hype up your girlfriends. But now, that badge of honor has morphed into a ubiquitous health and wellness archetype that panders to Western beauty ideals, especially on TikTok. (It’s also dominated by thin white women.) To date, the hashtag #thatgirl has accrued more than 5.7 billion views on the platform.

Online fitness is becoming more and more intertwined with performing pleasantness — and, by extension, being perceived as beautiful at all times. Whether this is positive or negative depends on the person consuming the content. It could inspire some consumers to pursue healthier habits or to organize their days in a way that makes more sense for them. And believing oneself to be an it girl can serve as a confidence booster.

But for others, aspirational content can exacerbate pre-existing insecurities. “There are certain people who are more susceptible to being influenced by others,” explained Joe Phua, a social media expert and professor at the University of Georgia. “They may feel like they need to live up to those standards that are seen in the video in order to be liked or to feel good about themselves.”

As more people post this type of content, it can become a convention. Those social codes can create unrealistic expectations and potentially cause people to think if their workout doesn’t fit into the bounds of that pattern, it’s not real. It enunciates the fine line between aspirational content and the reality of working out, which often results in looking a mess once the hard work is done. But since social media is a highlight reel of someone’s life, what does it mean to post this content online and uphold it as an aesthetic to hundreds or thousands of impressionable followers? And what are the effects of it becoming a trend?

I took this context into my conversation with Dr. Michele Kerulis, a former fitness instructor who is now a professor of counseling at the Family Institute at Northwestern University, specializing in sport and exercise psychology. During our conversation, we discussed what it means to uphold a look over health, the negative aspects of community building online, and how anyone who wants to post their content can do so honestly.

What are the pitfalls of uplifting an aesthetic in terms of exercise? Do you think this is an extension of externally derived gratification that’s commonly seen in fitness spaces?

While a lot can be controlled about the way we look, there is also a lot that we cannot control about our looks. A pitfall of focusing on aesthetics is that people might become preoccupied on some of these factors we can’t change. This can lead to a dangerous downward spiral of low self-confidence and high social comparison. Another pitfall is that focusing on aesthetics can distract you from the point of exercise — to maintain a healthy mind and body. Additionally, some people spend a small fortune on workout gear and clothes, so if people don’t budget well, they might overspend trying to keep up with others.

Before I was a professor, I was a group fitness instructor and I worked diligently to choose my language carefully as a way to uplift my exercisers’ confidence in their own unique abilities. I worked with people from a variety of ages and physical abilities, and it was important to me not to comment on their physical looks. After I demonstrated an exercise and watched the exercisers perform their reps, I would say things like, “Your form looks great!” or “Awesome technique!” I avoided phrases like, “You look great” because I wanted them to focus on the physical feeling of the movements, not on their aesthetic during exercise.

What are the potential issues with focusing on how someone looks during or after a workout?

Many people are concerned about how they look and often compare themselves to others. This is called social comparison theory, and it is seen frequently in the gym and other fitness spaces. During exercise, people look at others to see how easy or challenging workouts might be. This can be especially true in group fitness classes. If someone looks very put together and poised at the gym, others might think the workout that person is doing looks easy, when actually it could be quite hard.

Looking good is subjective. We all have a different idea of what attractiveness is and what we can do to enhance our own attractiveness. It can be hard to maintain what one defines as looking amazing during a workout, depending on the level of exertion and type of workout. For example, a person who takes a restorative yoga class might conclude class looking really good, and that same person might take a hot yoga class and end class looking like a hot, sweaty mess. Restorative yoga is meant to be relaxing in body and mind, and hot yoga is intended to increase heart rate and strengthen muscles in a high heat and humidity temperature-controlled room. We can assume this exerciser achieved the intended fitness goals during different workouts — relaxation in restorative class and an intense workout in hot yoga. With this example in mind, it is hard for us to tell others’ fitness goals based only on how they look.

I encourage people to focus on themselves during workouts so they can be in tune with their bodies and minds. When people constantly look at others for comparison — with the exclusion of your personal trainer or group fitness instructor — they not only put themselves at risk of becoming physically hurt by using improper technique, but they also could be negatively impacting themselves. Potential issues include decreased self-esteem by comparing yourself to others, the possibility of injury by not focusing on yourself, decreased focus on your own goals, and the inability to “mind-read” someone else’s goals just by looking at them.

How can this play out online?

Almost everything is amplified online due to the nature of the internet, and I see different types of interactions between people, specifically when we’re looking at fitness. But one thing that we know is having other people be aware of someone’s goals helps people stick to their goals. When you’re creating that kind of community around your fitness, that could be extremely positive.

It can be negative when people are posting for more harmful psychological purposes, such as boosting their self-esteem, as opposed to their true fitness goals. And other people might make negative comments and start trolling and really misinterpret the original poster’s intention.

So much of the fitness content we consume online is about achieving a certain body type. Do you think this trend is supporting that endeavor?

The trends we see on Instagram and TikTok definitely encourage certain body goals. For some, this can be motivating, but for others, this can lead to problems like eating disorders. We used to watch workouts on VHS and DVD to try to achieve our body goals, and that has evolved to streaming and social media. Motivational examples include Peloton instructors whose literal job it is to look good and motivate others, people who have overcome challenges related to illness and chronic disease, healthy weight loss success stories, and people who have healed from amputations. All of these people have different body types, and we can find many social media accounts that fall into these categories that encourage people to try their best to reach their own fitness goals. This might or might not include a specific body type.

It is okay to admire someone else’s physique and to be motivated by their social media accounts. This becomes problematic when someone thinks there is only one acceptable body type. We also must keep realistic expectations for our body type and body shape. There’s this beautiful curvy look that’s in right now. It’s okay to want to look curvy, but what does curvy mean for your own body? It’s okay to want to look strong. So what does strong look like for your specific body?

But I am pleased to see so many different body types, physical abilities, ages, and health conditions represented in positive ways on social media, and their aesthetic is a part of what makes their accounts successful and motivational.

What’s the difference between focusing too much on an aesthetic and having a feel-good ritual? For instance, I wear all black when I go to the gym because it gets me in the right head space. How is that separate from “I wanna look a certain way during and after this workout so that I’m conveying a specific message to my followers”?

Getting into that mindset and following your rituals is definitely important, and that’s for you. So as the exerciser, you’re saying, “I feel good when I have a new pair of shoes, when I’m in all black, or when I have my lucky headphones.” That’s an internal motivation for you. Wanting to look good before or after the physical workout is more of an external validation where people are looking for others to confirm that they’re worthy or good enough. With external validation, somebody might be looking for more comments, more followers, or more likes for a self-esteem boost and not necessarily for the passion of sharing exercise and fitness. Someone getting into their routine and posting that might encourage other people to find rituals that would be helpful for internal motivation.

It’s also fine for people to want to look good. It’s perfectly okay to have confidence and want to put our best foot forward. But we have to make sure that that’s for ourselves and not for others. When it starts being more for others than yourself, that’s when we notice some red flags. And sometimes, after a great workout, you might not look as good, but that’s okay too. You’re sweating!

Julia Craven is a writer covering anything she thinks is cool, and she’s the brain behind Make It Make Sense, a wellness newsletter.