What’s The Best Exercise For PCOS Weightloss? The Answer May Surprise You

By Clare Goodwin

Last updated: September 3, 2020

When you think of the best exercise for weight loss, you probably think of high intensity workouts which help you to burn hundreds of calories. But what about the best exercise for PCOS weight loss? The answer may surprise you…

In 2012, I signed up to run the Auckland marathon in New Zealand. It was probably my worst decision of the year. Not because I hate running, I love it. I have always been a competitive runner, so running a marathon wasn’t a big deal, at least for the old me. However, I didn’t want to complete this particular marathon because of my love of running or feeling of accomplishment. It was purely about getting the ultimate summer body.

I remember thinking that this was going to be my best pre-summer slim down ever. I trained for 140 hours over 10 weeks, ran countless miles, and burnt over 70,000 calories.

At the end of 10 weeks intense training, I’d lost 500 lousy grams.

Worse yet, I was injured and didn’t even get to complete the marathon! It was more devastating than Brexit.

We’ve all grown up being told that weight loss is simple: eat less and exercise more to create a calorie deficit. If this was true, then I would not have a business and PCOS weight problems would be easy to cure. All we’d need to do to lose weight is do an hour in a spin class every day. Your local gym will boast that this burns an average of 400-600 calories per class and the weight will fall off you.

However, PCOS is a condition with lots of hormonal factors at play. These mess with the ‘calories in minus calories out’ equation, meaning that the ‘exercise more’ part doesn’t contribute in the way that it normally should.

We may live in a world where many people do not exercise enough, but I see the opposite in my patients. The majority of them do too much cardio exercise that just isn’t helping. I was one of these people too. I was so frustrated about not being able to lose weight that I would exercise more and more. My thought process was along the lines of:

“Running isn’t burning enough calories, so let’s add in 4 cross-fit sessions. And if more is better, add on a couple of spin classes to boot!”

When I started studying functional medicine, over-exercising kept getting bought up as a potential cause of inflammatory diseases. After diving into studying the root cause of PCOS and the research around exercise, I was shocked. “What do you mean, running an hour a day or doing too many spin classes is making my PCOS worse? You must be joking! I’m burning calories – that’s the holy grail of weight loss!” For months I resisted the research, refusing to accept what science was showing me: exercise was good, but not the endurance exercise I was doing.

I was completely petrified to give it up. I felt like my daily work out was the thing keeping my weight from completely ballooning out of control. Instead, I continued to exercise and ignored the evidence. I clung onto it, ignoring the evidence. But I should have paid attention to Einstein: “The definition of insanity is doing the same thing and expecting a different result.” I’d been running for years and had never seen any kind of weight reduction. Instead, my weight had slowly crept up, year after year.

The other reason I clung so tightly to this ritual was because I absolutely loved running, and I still do today. I love the time to myself, to think and de-stress. However, I came to realise that if I wanted to reverse my PCOS then I was going to have to focus on what was going to help me do that. If that meant giving up long runs and focusing on short, high-intensity exercise, then I would do it. Recovering from PCOS was my top priority.

I know that this goes against everything you’ve ever known about exercise and is quite hard to stomach. However, it’s important to understand this if you want to reverse your PCOS.

Three reasons why more exercise is wrong

There are three reasons why the ‘exercise more’ part of the calorie equation doesn’t quite stack up:

  1. Caloric burn from exercise is actually really small.
  2. Working out for an hour or more increases our cortisol, making us hold onto fat.
  3. We tend to overeat after we’ve worked out.

1. You’re not burning as many calories as you think

Research has shown that working out to burn calories doesn’t really work. A study that followed 54 men for 6 months, exercising 4 times/wk for 1 hour (at 70% V_O2 max) showed they lost an average of just 1.8kg in that time. A similar study in women found no body fat loss after an 8 week exercise programme.

These aren’t the only studies to show these kind of results. In fact, 43 studies have shown the same result. The Cochrane group conducted a review of these studies. All studies were 3-12 months long and included an average of 45 minute sessions, 3-5 times a week. This means that participants spent, on average, 69 hours exercising during the studies. The meta-analysis found that the average weight loss was 1kg. 1kg after 69 hours of working out? Disappointing, right?

2. Endurance exercise makes you store fat

Cortisol is a hormone that’s released during long-term periods of stress. It’s elevated when we are under chronic stress, but also during and (many hours) after endurance exercise.

Cortisol is elevated when there is a perceived threat. When our ancestors wandered the Sahara, the danger was usually from animals or a rival tribe and we had to run or fight to stay alive. Cortisol helped by releasing glucose into the bloodstream, supplying our muscles with the energy they needed.

Conversely, in our modern day corporate world, we’re going from our morning gym class to sitting all day. Combine this with a morning coffee and a high pressure job, which both increase cortisol, and we are literally soaking in an all-day long cortisol bath.

For the 70% of women with PCOS who have insulin resistance, this is a recipe for disaster. Cortisol is continually pumping glucose into the blood, but our muscles aren’t doing any work. The body does not like glucose just sitting in the blood, so it raises the glucose storing hormone, insulin, to store the glucose for later use. However, if you have insulin resistance then this process doesn’t work. The glucose has to be stored somehow, so it’s stored as fat.

The hard truth is that running or a spin/gym class may actually be making you gain weight, not lose it. It’s raising your cortisol, which is making you store more fat, and making you more insulin resistant to boot.

3. “I worked out today, I’ve earned that chocolate bar”

Yes, it’s true, we all do it. While we might not think we do it enough to override all of the calories we burn, we actually do. Studies have shown that we really do think we’ve earned those extra treats.

A study that compared two groups of women: one that had exercise for 50 minutes at a relatively high intensity, and one that did no exercise. The exercise group not only ate more, but they preferred higher fat, sweet foods. Moreover, the researchers hypothesised that this was completely involuntary. Some of us are apparently predisposed to crave that chocolate bar, instead of reaching for a can of tuna or a handful of carrots.

So, what’s the best exercise for PCOS?

Don’t get me wrong, exercise is super helpful in reversing PCOS, but we just need to do the right type. That is exercise which:

  • Improves your insulin resistance
  • Burns calories, while reducing androgens and cortisol levels

Improving insulin resistance: short HIIT

70% of women with PCOS have insulin resistance. Insulin resistance is a significant contributor to many of the symptoms we suffer, the most obvious being weight gain. Studies have shown that short, high intensity interval training (HIIT) improves insulin sensitivity during and (up to 1-3 days) after high intensity exercise.

What exactly is HIIT? It’s things like lifting heavy things and sprinting, but for very short periods, with rest in between, for a maximum of 20 minutes.

Burning calories while reducing ACTH and cortisol levels

Alongside the HIIT workouts, you should be trying to do as much physical activity as possible. This will help to not only burn calories, but also decrease cortisol and inflammation.

Studies have shown that low intensity activity, such as walking or slow cycling, actually decreases cortisol levels. This will help to further reduce inflammation and insulin resistance.

Low intensity activities have also been shown to reduce ACTH, which stimulates our body to produce more androgens (‘male’ hormones). These male hormones are responsible for some symptoms of PCOS, such as acne and unwanted hair growth or loss.

A good way to incorporate low intensity exercise into your day is by actively commuting to work, going for a walk at lunchtime and during breaks, meeting friends for a walk instead of a coffee, and taking up an active hobby like hiking or kite surfing.

In the corporate world we sit a lot. Unfortunately, standing meetings never really took off, and you don’t want to be the weirdo always trying to push them or lurking in the back corner of the room while everyone else is sitting. But you are in control of time at your desk. So if you haven’t got a standing desk then get one. You’ll burn 75% more calories a day (up to 800 more) by standing instead of sitting.

What about my cardiovascular health About My Cardio Health?

Running and endurance exercise has often been promoted as the king of cardiovascular health: building our heart, lungs, and vascular system to protect us from heart attacks, strokes etc. However, studies have proven HIIT to be just as effective in improving cardiovascular health. Better yet, it’s 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) with steady state cycling for 40 minutes (cardio). As expected, both forms of exercise increased cardiovascular health. However, HIIT was found to have many other benefits for participants, including:

  • Significantly decreased weight and fat mass.
  • A significant loss of fat around the stomach and legs.
  • Improved insulin sensitivity.
  • Significantly improved leptin (satiety hormone) sensitivity.

The most interesting thing about these results was that they had nothing to do with calories burnt during exercise, as both groups burnt the same amount of calories!


High intensity running or aerobics classes don’t actually help you lose weight and may be making your PCOS worse.

Even if you love endurance exercise (like me!), focus first on reversing your PCOS. Then you can look at getting back into more endurance exercise.

Get as much ‘movement’ in your day as possible:  walk or cycle to work, take a walk during break time, walk between meetings, use a standing desk, and catch up with friends for a walk rather than a coffee.

Focus on 3 x 15-20 minute workouts a week, lifting heavy things and sprinting.