Does HIIT give you acne? My skin completely cleared up when I quit — I asked an expert why

I hate to be this person, but outside of the occasional hormonal flareup, or a breakout after an accidentally-left-my-makeup-on-after-a-night-out, I generally have always had pretty clear skin.

Over the past few years, I had lost the motivation to go to the gym myself and had started going to HIIT workout classes regularly. While many people around me had great results, I never quite saw the same but enjoyed the group atmosphere and loved having a schedule to keep me accountable.

However — around the same time that I started ramping up these workouts, I began getting painful cystic acne on one side of my face. I blamed everything – from cutting out dairy to getting a silk pillowcase, and even ditching the skincare I had been using forever – but never thought it could have come as a result of the HIIT workouts I was doing.

Over the summer I ditched my expensive membership and my skin began to clear up — but it wasn't until I saw a TikTok of a woman in a similar situation that I really started to think about how HIIT impacted my skin.

To learn more about the impact of HIIT workouts, especially on women, I reached out to Dr. Rebecca Karlin, a Toronto-based naturopathic doctor who specializes in hormonal imbalances in women.

Is it common to break out when you do HIIT?

Yes, says Karlin.

“A lot of women will come in and they're working out very intensely, and they don't know why they can't lose weight. They don't know why they're breaking out. They don't know why they're losing their hair. This is something I see very often," she says.

In many cases, she says these types of symptoms can point to a cortisol imbalance.

What is cortisol?

According to WebMD, cortisol is like “nature’s built-in alarm system” and acts as the body’s main stress hormone, working with certain parts of the brain to control things like mood, motivation and fear. It can even be linked to the physiological response known as “fight or flight.”

Cortisol also plays a crucial role in other bodily functions, including inflammation, blood pressure, blood sugar, the sleep/wake cycle, digestion of carbs, fats and proteins and balancing energy.

“For men or for women, when we're working out, we're definitely influencing our hormones. Specifically, one hormone we can focus on is cortisol, which is our stress hormone. And so for women, a lot of us tend to be kind of adrenal dominant.”

What Karlin means by this is that imbalances in the adrenal system, such as cortisol levels, are an underlying cause of many conditions for women, and can contribute to many other health issues. Studies show that the body can actually put itself in this “fight or flight” mode when women are performing intense, rigorous forms of exercise.

There are signs to look for when assessing if a workout is right for you.

“One really big thing that I see in people, and specifically talking about women, is that an hour or two after their workout, they crash – they feel exhausted, and they want to just nap,” she explains. “If you're working out and then you feel exhausted after your workout – I don't mean directly after, I mean a little bit later in the day – that might be a sign that that workout was a little bit too intense for you.”

As mentioned, cortisol can also impact the sleep/wake cycle, which is another way to tell if your levels are off: “If you're someone who feels like at night you're both wired but tired at the same time, that's an indication that there might be something going on with your cortisol levels.”

When cortisol levels are high, women can also present symptoms like acne, fatigue, insomnia, anxiety, difficulty concentrating, high blood pressure, muscle weakness, mood swings and more. Because these symptoms also can be signs of other health concerns, they can sometimes be overlooked by health professionals.

The role of PCOS

Polycystic ovary syndrome (known as PCOS) can also play a factor for some women when it comes to working out. Exercise can impact those with PCOS on a greater level because of the same cortisol hormones being impacted, and also the impact on the adrenal system generally.

Being impacted by high-intensity exercise does not necessarily mean that you have PCOS.

“Both women who have PCOS and women who don't have PCOS can be impacted by this very intense, very rigorous high-intensity cardio exercise," Karlin says. "Women who have PCOS are genetically predisposed to developing PCOS, but not all women have those genetics. Some women will simply spend their time exercising intensely, and their cortisol will start to go up, and then their inflammation will go up.”

Other workouts to try instead

Karlin suggests that paying attention to your body and balancing your workouts accordingly can help support a healthy hormonal balance.

“Generally, if you're just trying to kind of mitigate cortisol response, and workout in a way that balances your or that supports a hormone balance, what I typically like to see in my patients is a healthy mix of weightlifting, plus more moderate cardio exercise. Nothing too high intensity, especially not regularly.”

She adds: “When you are working out, you don't want to be at this place where your heart rate is going very quickly, and you're panting and you can't catch your breath. You want to take breaks in between your sets.”

Karlin also doesn't recommend working out on an empty stomach.

“You probably don't want to be over-exercising when you're under-consuming calories," she says. "That's going to be a stressor on the body. And if you pair that with another stressor, like high-intensity cardio, it's like a double whammy.”

Get in sync with your cycle

Your cycle can, of course, also have a big impact on your hormones, and can be worth paying attention to when it comes to exercise.

“A lot of people like to work out with their cycles as well,” Karlin says. For those interested in aligning their workouts to their cycle, she recommends the following as a guideline:

• When you're on your period, try something that's a lighter intensity; a walk or a light Pilates class.

• When you're like in your follicular phase, your estrogen is coming up, your testosterone is coming up, try something like weight training when you're ovulating. That's when you have kind of the most energy you have the peaks of your hormones, so it is a better time for high-intensity training.

• When you're in the luteal phase (after ovulation), try something a little bit more low-impact.

As always, if you’re having strange or uncommon symptoms, listen to your body and consult a professional who may be able to help diagnose what is happening and suggest alternatives that work best for you.