PCOS Exercise: Is Your Work Out Making You Gain Weight?

By Clare Goodwin

Last updated: September 3, 2020

Let’s talk about PCOS exercise! I can remember a time… years ago. It was a Wednesday morning during my second year of university and I was sitting in  nutrition class on those vinyl covered auditorium seats.

We had just started a module on Type 2 diabetes and I was bored. I knew that I should be paying more attention as I would inevitably end up working with patients with Type 2 diabetes. But I was being selfish that day: I wasn’t interested because I thought I’d never have to worry about developing Type 2 Diabetes.

It’s human nature that we’re only interested in things that are applicable to us. How many people study the inner workings of their kitchen sink until it’s blocked, overflowing, and smelling like a small rodent just died down there?

I was a competitive athlete. A runner and triathlete competing at world championships, training up to 25 hours a week and eating a strictly low fat diet. The World Triathlon Champs were in Germany that year and I was only weeks away from setting off to go join the rest of the team in Geneva. I was due to take part in practice races at the Swiss National Champs before heading over to Germany.  

I remember the smugness I felt as I read through the slide on risk factors. High fat diet, inactivity, overweight, high blood pressure.  Those things were hardly applicable to my lifestyle of a low fat diet and intense exercise.  

Fast forward two years…

…and I was sitting across from my GP while she told me I was severely insulin resistant and bordering on being a Type 2 Diabetic. I sat there, mouth gaping, as she gave me a stern lecture about how I needed to ‘try exercising more’ or I’d be back in there within the year as a full blown diabetic.

Little did she know that I was already exercising for at least 20 hours a week. It seemed that exercising more wasn’t the solution, it was part of the problem. This wasn’t the model I’d been taught. I’d been taught that you only developed Type 2 Diabetes by eating too much macaroni cheese while watching endless amounts of reality TV.

Despite my diet and exercise regime, I’d always been on the heavier side. It had been a constant battle to keep my weigh in check. I knew I’d spent the last decade in a calorie deficit, so how was I now developing Type 2 diabetes?  It didn’t add up. I felt enraged and cheated. I was the ‘healthiest’ person I knew, so why was I now developing a disease that I thought was only for lazy, fat people?

PCOS exercise: Too much exercise could be causing your PCOS or making it worse

My example is extreme, but I see the same physiological changes in women doing an hour run, spin class, or gym class on a daily basis.

PCOS is an excess of androgenic hormones. This isn’t just testosterone, but also androstenedione, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEA-S). These hormones are not only produced by our ovaries, but by our adrenal glands too. In fact, our adrenal glands are actually responsible for 20-30% of all androgenic hormones produced.

Adrenocorticotropic hormone (ACTH) is the first hormone to respond to stress. It acts on the adrenal glands to produce the stress hormones adrenaline, noradrenaline, and cortisol (our long term stress hormone). It also leads to the release of androgenic hormones. These androgens cause the symptoms associated with PCOS, especially acne, unwanted hair growth and loss, and cystic ovaries.

If too much cortisol is released, the body has a negative feedback loop that inhibits more production. However, there is no feedback loop in the case of androgens. This means that stress (including prolonged, hard exercise) makes our bodies produce increasing amounts of androgens, which makes our PCOS worse.

PCOS exercise and cortisol

Studies have shown that lean PCOS women produce more cortisol than other women. We also know that being overweight causes our body to produce more cortisol. Combine this with a daily spin session at the gym, a high stress job, a busy social life, and a lack of sleep… Your cortisol could easily be 3 times the normal range like mine was in 2012 when I was training for an hour a day.

Exercise increases cortisol and ACTH levels by between 40% and 80% depending on the intensity of the exercise. These levels can remain high for hours after you finish exercising. 

In summary:

  • Elevated androgens lead to PCOS symptoms, such as menstrual dysfunction, unwanted hair growth, weight gain, acne, and mood disorders.
  • The adrenal glands are responsible for at least 20-30% of the elevated androgen levels seen in PCOS.
  • Chronic stress, or exercising intensely for an hour, elevates ACTH. This stimulates androgen secretion, for which there is no negative feedback loop.

But what about the calories I’ll burn!?

Sorry to break it to you, but caloric burn is not all it’s cracked up to be.

We’ve all been taught the calorie equation encouraging us to exercise more to ‘burn’ calories. We think that the more exercise, the better! Surely an hour long gym class a few times a week is the way to go? Unfortunately, studies have proven this wrong.

The Cochrane group conducted a review of 43 studies. These studies lasted between 3-12 months, with average gym sessions lasting 45 minutes, 3-5 times a week. Participants exercised for an average of 69 hours during the duration of the study.

Guess what they found? The average weight loss was 1kg for 69 hours of working out. Disappointing or what?

PCOS Exercise: What should you be doing instead on an hour long gym class or run?

Don’t get me wrong, exercise is really helpful in reversing PCOS. I personally love working out, especially running and crossfit. I love the competitiveness, the endorphin rush, and pushing my body to the edge. So learning to stop overworking myself was really, really hard. To be honest with you, it’s still something that I battle with.

The ‘Go Hard or Go Home’ high mentality is so deeply rooted that it takes time to override. However, I realised that after years of doing more exercise and eating less to try to lose weight, it really wasn’t working for me. I needed to follow what the scientific research recommended. This was:

  • Exercising to improve insulin resistance.
  • Exercising to burn calories, while reducing ACTH and cortisol levels.

Improving insulin resistance: HIIT me!

70% of women with PCOS have insulin resistance. Insulin resistance is a significant contributor to many of the symptoms we suffer. However, high intensity exercise can help to improve this. Studies have shown that high intensity exercise can help to improve insulin sensitivity for up to 3 days.

What about my cardiovascular health?

Endurance exercise has long been promoted as the king of cardiovascular health. It builds our heart, lungs, and vascular system, protecting us from heart attacks, strokes etc. However, studies have proven that HIIT is just as effective in improving cardiovascular health. Better yet, HIIT been shown to be more effective in improving almost every other marker of health.

One study compared sprinting on a bike for a maximum of 20 minutes (HIIT) versus steady state cycling for 40 minutes (cardio). Results showed that whilst both exercises increased cardiovascular fitness, only those in the HIIT group:

  • Significantly decreased weight and fat mass.
  • Lost a significant amount of fat around their stomach and legs.
  • Significantly improved their insulin sensitivity.
  • Significantly improved their leptin (satiety hormone) sensitivity.

It’s worth noting that both groups burnt the same amount of calories, so the results had nothing to do with calories burnt during exercise. Find a woman who wouldn’t want these results!

How to burn calories while reducing ACTH and cortisol levels

Alongside HIIT, you should be trying to do as much incidental physical activity as possible. This will help to burn calories, while also decreasing cortisol and inflammation.

For example, studies have shown that low intensity activity, such as walking or slow cycling, decreases cortisol levels. This will help to further reduce inflammation and insulin resistance. Low intensity activity also helps to reduce ACTH.

Additionally, low intensity exercise can help burn more calories without the added exertion. For example, studies have shown that people who work at a standing desk burn up to 75% more calories per day than those who sit.

PCOS Exercise: summary

Exercise for PCOS, especially for improving insulin resistance, is great. But if you’re doing medium to high intensity cardio for more than 30 minutes then you may be doing more harm than good.

Instead of going for an hour-long run or spin class, opt instead for:

  • Short amounts of high intensity sprinting OR
  • 20 minutes of heavy resistance (weights) exercise

Make sure to also get in as much low intensity activity, such as walking and standing, as possible throughout the day.