“Cortisol” is all over social media with information on how it spikes and ways to “balance the hormone.” From supplements to detoxes, it can feel like a lot of information and—go figure—may stress you out. Cue the “cortisol creep” from information overload alone. Cortisol may be buzzy right now, but endocrinologists say it’s worth understanding what it actually is and what it does so you can take steps to manage your levels.
“Cortisol is a steroid stress hormone made by the adrenal glands, which are triangle-shaped glands on top of the kidneys,” explains Dr. Jennifer Cheng, DO, the chief of endocrinology at Hackensack Meridian Jersey Shore University Medical Center. “It plays a role in the response to stress and metabolism, and is a hormone that changes levels throughout the day. Typically, the high point occurs in the morning when you get up.”
It’s normal for cortisol levels to go up and down during the day, but you don’t want them to be chronically high. Seemingly very small habits can keep cortisol in check or silently raise it.
“I always tell patients that being healthy boils down to focusing on sleep, diet and exercise in that order,” Dr. Andres Splenser, MD, an endocrinologist with the Memorial Hermann Health System, tells Parade. “Doing those basic three things often translates into not only feeling better but being healthy hormonally. Lack of sleep, stress, poor diet and, of course, lack of exercise all affect hormone production, ranging from stress hormones to testosterone/reproductive health.”
Interestingly, you may think you’re nailing one of these core habits, but you’re raising stress levels. Knowing what it is will help you take a healthier approach to your routine. To help, endocrinologists reveal the “healthy” habit that silently raises cortisol.
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The ‘Healthy’ Habit That’s Silently Raising Your Cortisol, According to Endocrinologists
Endocrinologists say that high-intensity interval (HIIT) workouts can raise your cortisol levels, but you may not realize it. Dr. Cheng explains that HIIT workouts involve high-intensity exercise followed by brief recovery periods—think 30 seconds of burpees, then 10 seconds of rest. Your heart rate isn’t the only thing that goes up during these sessions.
“HIIT can cause a temporary spike in cortisol levels,” she says. “The body gets the signal from the brain that increased physical activity is occurring, and stress hormones such as cortisol are released.”
The cortisol actually serves a physiological purpose during a HIIT workout. Dr. Victoria Finn, MD, a board-certified physician with Medical Offices of Manhattan and a contributor to labfinder.com, explains that it increases blood sugar levels. That’s not necessarily a bad thing—your brain and muscles need it for energy. Cortisol is also in there supporting your blood pressure, heart rate and cardiovascular energy to optimize your performance and recovery from the intense exercise.
“In simple terms, cortisol helps the body push through short bursts of strenuous activity,” Dr. Finn says.
Studies, including a 2021 meta-analysis, have shown that cortisol rises right after a single HIIT session, then falls below your normal levels and returns to baseline after 24 hours.
“Cortisol spikes that are temporary are not bad,” Dr. Cheng explains. “The problem is when there are chronically elevated cortisol levels.”
She says that elevated cortisol may contribute to:
- Weight gain
- Diabetes risk
- High blood pressure risk
- Muscle weakness
- Bone thinning
- Anxiety
- Depression
- Sleep issues
Typically, chronically high cortisol is the result of a condition like Cushing’s syndrome, when a tumor overproduces the hormone. Dr. Finn stresses it’s important not to self-diagnose high cortisol (even though social media personalities post checklists of symptoms). If you’re concerned, an endocrinologist may perform specialized testing.
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Wait—Are HIIT Workouts Bad for Cortisol?
Not necessarily. “Stress from exercise is a good thing,” Dr. Splenser explains. “Because HIIT involves repeated bursts of very high effort, it produces short spikes in cortisol along with other ‘fight-or-flight’ hormones like adrenaline.”
However, Dr. Splenser emphasizes that the cortisol levels don’t stay like that—they drop within an hour.
“Importantly, with regular training, the body adapts,” he explains. “Baseline cortisol levels often decrease, and the stress response becomes more efficient. In this context, HIIT-related cortisol increases are temporary, appropriate and part of a healthy metabolic response, not harmful excess.”
Still, it’s possible to overdo it with HIIT, especially at first. Dr. Splenser doesn’t suggest going from the sofa to a daily HIIT workout. “Slow and steady wins the race, and too much exercise too suddenly can cause problems, of course,” he says. “I would suggest checking with your physician to discuss your fitness level, workout intensity plan and to start gradually. Seeking the advice of a trainer who can set up a gradual training plan is also a good idea.”
Even as you do progress with HIIT, Dr. Finn doesn’t recommend doing it daily. “Individuals in good physical condition may be able to perform HIIT every other day,” she says. “Ideally, it’s recommended to alternate activities rather than engage in high-intensity training daily.”
For instance, she suggests you might do a HIIT workout on Monday and then focus on brisk walking, strength training and stretching throughout the rest of the week. Recovery days are also crucial.
“Overtraining without sufficient recovery can expose the body to additional stress,” Dr. Finn says.
Your best HIIT cadence is highly personal and can change. Dr. Finn suggests looking out for signs that your body (including your nervous system) needs more rest. She says the signs you may need more post-HIIT recovery days include:
- Persistent fatigue
- Worsening sleep
- Declining exercise performance
- Elevated resting heart rate
- Irritability
Related: What Happens to Your Blood Sugar When You Eat Cottage Cheese?
3 Healthy Habits for Cortisol Levels
Balancing HIIT with other workouts and ensuring adequate recovery is one way to manage cortisol levels. Endocrinologists say that other habits also matter for balancing cortisol. Below, they shared three healthier habits than doing HIIT workouts every day.
1. Practice stress management and recovery techniques
Dr. Finn points out that physical and emotional stress can increase cortisol levels.
“Simple techniques such as meditation, breathing exercises, outdoor activities, social connections and a healthy work-life schedule can help reduce excessive stress overload,” she suggests. “The goal is not to fully suppress cortisol but to facilitate the body’s efficient return to baseline after any stress-induced spike.”
2. Optimize your sleep
High stress can make it harder to fall and stay asleep. But Dr. Finn shares it’s worth working on both because sleep helps regulate cortisol production.
“Cortisol normally follows a circadian rhythm, peaking in the morning and declining at night,” she says. “Chronic sleep deprivation or a poor sleeping schedule can disrupt this rhythm, leading to chronically elevated cortisol levels. Maintaining a regular and restorative sleep schedule supports healthy hormone balance, overall recovery and metabolism.”
3. Get professional help
If you’re struggling with stress, you’re not alone. You also don’t have to “fix the problem” yourself.
“Consider going to your primary care doctor or health care provider if you have concerns about elevated stress levels and…obtaining a referral to a therapist or psychologist,” Dr. Cheng says.
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Sources:
- Dr. Andres Splenser, MD, an endocrinologist with the Memorial Hermann Health System
- Dr. Jennifer Cheng, DO, the chief of endocrinology at Hackensack Meridian Jersey Shore University Medical Center
- Dr. Victoria Finn, MD, a board-certified phsyician with Medical Offices of Manhattan and labfinder.com contributor ‘
- Acute effect of HIIT on testosterone and cortisol levels in healthy individuals: A systematic review and meta-analysis. Scandinavian Journal of Medicine & Science in Sports.
