Why muscle might be the missing PCOS treatment

Muscle - a hidden treatment for PCOS

Hello everyone,

One of the most potent treatments for PCOS is muscle. You heard that correctly, treatment. I wish we prescribed: “increase muscle mass”, “eat micronutrients”, “be mindful”. That would be my PCOS prescription.

Why is muscle so important?

Our muscles are the largest storage site and site of metabolism in our entire body. Approximately 70–90% of the glucose from our meals is stored in muscle cells. The following places it goes to are the liver and then the fat cells.

Most adults store about 500g of glycogen (the stored form of glucose) or 2000 calories in their muscles. Compare that to the liver’s 100g, which is about 400 calories. The larger the muscle mass, the more glycogen it can store, which is yet another reason to build muscle. Glycogen molecules get stored between these fibres that you see in the image. FASCINATING.

This is, of course, functional. Your heart is a muscle, so it constantly needs energy to pump. Imagine if the glycogen was stored somewhere far, it would be too much work to transport it. All our muscles carry us throughout our activities and keep us safe.

All muscle cells are equipped with tiny doorways called GLUT4 transporters. When we eat and insulin rises (or when we exercise), these GLUT4s move to the cell’s surface, and open to let in more glucose. Once inside, glucose has several options: it can be converted into glycogen for storage or burned to produce ATP for energy.

Why is muscle extra important for us?

When you eat, your blood sugar rises. Your body releases insulin, a hormone that “unlocks” the GLUT4 transporters’ doors on muscle cells. Insulin tells GLUT4 to move to the cell’s surface and pull glucose inside, clearing sugar from your blood.

In insulin resistance (as seen in PCOS and type 2 diabetes), the “keyhole” for insulin gets jammed. GLUT4 doesn’t move as well, so less glucose gets stored in the muscle. Sugar sticks around in your blood (causing higher blood glucose) and the whole PCOS havoc.

Here’s the great thing about muscle

Muscle contractions open GLUT4 doors even without insulin’s help

When you move your muscles, even just going for a walk or doing any physical activity, the movement itself sends signals inside muscle cells:

• AMPK Activation: When muscle “runs low” on energy (like during exercise), AMPK flips on, telling GLUT4 to open up.

• Calcium Signals: Muscles contract using calcium. These calcium waves trigger changes inside the cell, nudging GLUT4 to the surface.

• Nitric Oxide: Exercise increases blood flow. Nitric oxide helps deliver glucose and further signals GLUT4 movement.

All of these pathways work independently of insulin. So, even if your “insulin machinery” is broken, these exercise signals still cause GLUT4 to open its doors. Voila!!

Due to the numerous benefits of muscle, studies indicate that individuals in the lowest muscle mass tertile exhibit 45% lower insulin sensitivity compared to those with higher muscle mass.

So, imagine that instead of being told to lose weight (which also wastes some muscle), we were told to focus on building muscle. I believe that positive reinforcement can have a significant impact on our mental health.

The proof

I find it pretty sad that the number of studies focused on strength training is quite limited. Very few measure muscle mass as a measure of success. There are probably two reasons for it:

1. The focus on muscle has been predominantly a male-focused activity for a long time. It’s only now that you see more women weightlifting.

2. The focus for exercise in women with PCOS has always been weight loss and BMI, so there are a lot of studies done on cardio and focused on weight loss

A system review published in 2020 looked at:

• Aerobic training: 11 studies

• Strength (resistance) training: 2 studies

• Combined aerobic + strength training: 5 studies

Aerobic training generally showed improvements in:

• Body composition (weight, BMI, body fat %)

• Cardiorespiratory fitness (VO₂ max)

• Insulin sensitivity and glucose metabolism

• Menstrual regularity and ovulation rates in some studies

Strength training (fewer studies, smaller samples) showed:

• Gains in lean body mass

• Reduction in fat mass

• Improved insulin sensitivity

• Less consistent effects on menstrual cycles compared to aerobic training

Combined training tended to produce the largest overall benefits, improving both metabolic markers and body composition more than either type alone.

The main takeaway is that aerobic training has more evidence behind it simply because it has been studied more, but strength training appears promising, especially when combined with aerobic exercise, though more research is needed to confirm the above benefits.

The conclusion

A switch from HIIT to strength training has made one of the most significant differences to my PCOS, my ability to keep my weight stable and my period regular. My recommendation to you is to combine them. I still do a spin class once or twice per week. Your cardiovascular health is also essential, so combining the two will likely yield the best benefits.

See you next week,

Francesca

¹ References

1. Liu, Y., Li, S., Wang, Y., Zhang, X., & Sun, J. (2024). Effects of high-intensity interval training on strength, speed, aerobic capacity, and anaerobic capacity in racket players: A systematic review and meta-analysis. PLoS ONE, 19(1), e0295362.

2. Gordon, B.R., McDowell, C.P., Lyons, M., Herring, M.P. (2017). Resistance exercise training and quality of life in adults with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials. Diabetes Research and Clinical Practice, 127, 263–274.

3. Pattyn, N., Cornelissen, V.A., Eshghi, S.R., & Vanhees, L. (2014). The Effect of Exercise on the Cardiometabolic Health of Patients With Cardiovascular Disease, Diabetes or Prediabetes: A Systematic Review. European Journal of Preventive Cardiology, 21(4), 489-503.

4. Weston, K.S., Wisløff, U., & Coombes, J.S. (2014). High-intensity interval training in patients with lifestyle-induced cardiometabolic disease: A systematic review and meta-analysis. British Journal of Sports Medicine, 48(16), 1227-1234.

5. Jelleyman, C., Yates, T., O'Donovan, G., Gray, L.J., King, J.A., Khunti, K., & Davies, M.J. (2015). The effects of high-intensity interval training on glucose regulation and insulin resistance: A meta-analysis. Obesity Reviews, 16(11), 942-961.

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