Hello everyone,
Today I bring you a lovely conversation with Registered Dietitian Tara | PCOS Journal about HIIT workouts and how they impact PCOS.
Among PTs and fitness influencers, HIIT is praised as the ultimate solution for weight loss. Short bursts. Maximum burn. Efficient and powerful.
On the other side, women with PCOS are told that HIIT is “too stressful,” that it spikes cortisol, that it ruins hormones, and that we should avoid it altogether.
As usual, the truth sits somewhere in between. In this episode, we go through:
HIIT and cortisol - is it true that it messes with your hormones?
Should HIIT be off-limits?
What type of exercise is best for PCOS?
This episode can be listened to on all major platforms, including Spotify, Apple and YouTube. If you prefer reading, I have summarised it below.
I share snippets from our conversation and short-form content on Instagram. Follow us there:
The problem with absolutes
One of the first things Tara said was that anyone speaking in absolutes is usually a red flag. Whether they have credentials or not. I couldn’t agree more with this.
“Women with PCOS should never do HIIT” is just as problematic as “HIIT is the only way to exercise with PCOS.”
Research shows that HIIT can improve insulin sensitivity and metabolic markers in women with PCOS. From a purely metabolic standpoint, HIIT can be beneficial. The issue is how and when it’s being done.
Exercise is a stressor, but not all stress is bad
We spoke about something that often gets oversimplified on social media: cortisol.
Exercise raises cortisol, but only temporarily. It is an acute stressor. And when you are well-rested and properly fuelled, your body adapts positively to that stress. That’s how we build cardiovascular fitness, build resilience and improve insulin sensitivity. The good time of stress.
The problem arises when HIIT is layered on top of chronic stress:
When you’re sleeping five hours a night.
When you’re under-eating.
When you’re in a calorie deficit trying to lose weight.
When work is overwhelming.
When your nervous system already feels on edge.
I was that person: doing HIIT on an empty stomach, in a calorie deficit, on top of a stressful job.
By 3pm, I was ravenous. Cravings were intense. I felt out of control around food and blamed myself for lacking discipline.
Guess what? My PCOS was not happy, and my period was nowhere to be seen. I wasn't losing weight either, so it all felt a bit like a scam.
The body does not prioritise reproduction during perceived stress. If your system senses that resources are scarce or recovery is inadequate, ovulation is not at the top of the list, because realistically, you should not get pregnant in times of high stress, as it’s likely to not lead to a healthy baby.
In addition to the stress element, doing HIIT underfed puts your muscle mass at risk. Muscle is one of our most powerful tools in PCOS. It acts as a glucose reservoir. The more metabolically active muscle we have, the better our bodies manage blood sugar.
Again, the problem is not HIIT itself. It is the context in which we do HIIT.
Should HIIT be off-limits?
No, HIIT has evidence for PCOS specifically. If you love HIIT, feel energised by it, recover well, and your labs and symptoms are improving, there is no reason to remove it purely because someone online told you it’s “bad for PCOS.”
On the other hand, if you hate it, dread it, and are forcing yourself to do it because you think it burns the most calories, that’s a different conversation.
Consistency matters more than intensity, and variety matters too.
Strength training has strong evidence in PCOS for improving insulin resistance. Lower-intensity cardio supports cardiovascular health. Restorative movement helps regulate the nervous system. Yoga, pilates and pretty much all forms of movement have evidence to help improve PCOS symptoms.
Rather than asking “Is HIIT good or bad?” a better question might be:
What form of exercise can I do for a year straight and not hate it?
Because exercise does not exist in isolation from the rest of your life.
The bigger picture
One of the underlying themes in this conversation and honestly in all of our conversations, is that we often major in the minors.
We obsess over whether HIIT is allowed.
Whether cardio is harmful.
Whether yoga is better.
Whether we should only walk.
Meanwhile, the foundations are sometimes shaky.
Are you eating enough whole foods?
Are you consuming adequate protein?
Are you sleeping?
Are you managing psychological stress?
Are you moving your body enough?
Most of the meaningful change in PCOS comes from these fundamentals.
HIIT can absolutely be part of that. It is not the villain. It is not the saviour. It is a tool, and like any tool, its impact depends entirely on how, when, and why it’s used. The internet loves extremes, but your hormones will respond to consistency.
See you on Sunday,
Francesca
