Fuelling Your Workouts with PMOS: The Complete Guide

"Should I eat before I exercise? I'm worried about insulin resistance, so I don't really want to spike my blood sugar."

I've had versions of this conversation more times than I can count.

Sometimes it's someone heading out for a run on nothing but a coffee. Sometimes it's a woman who has a handful of berries before a gym session because she's worried that eating anything more will "undo" her workout. Other times it's someone who's convinced herself that feeling completely exhausted after exercise is just part of having PMOS (formerly PCOS).

If any of that sounds familiar, I want you to know that you're not alone.

One of the biggest nutrition mistakes I see women with PMOS making isn't eating too many carbohydrates. It's not eating enough around exercise.

For years, women with PMOS have been told to be careful with sugar and carbohydrates. These are all sensible conversations to have, but somewhere along the way many women have unintentionally started believing that eating before or after exercise is something to avoid.

The irony is that this is one of the times your body often needs carbohydrate the most.

The good news is that this doesn't have to involve expensive supplements, protein powders or complicated nutrition plans. For most women, making sure they're eating enough before and after exercise can be as simple as a bowl of cereal, a banana, some toast or even a glass of chocolate milk.

This guide brings together everything I want you to know about fuelling your workouts with PMOS - why it matters, how to tell if you're under-fuelling, and exactly what to eat before and after exercise in real life.

Could you be under-fuelling your workouts?

One of the reasons under-fuelling is so easy to miss is because the signs aren't always obvious. Most women don't think, "I wonder if I'm not eating enough around my workouts?" Instead, they assume they're unfit, not trying hard enough or that this is simply what exercising with PMOS feels like.

Sometimes it is. But quite often, it isn't.

Here are some of the things I commonly see in clinic.

🚩 Signs you may not be eating enough around exercise

• You regularly exercise first thing on nothing more than a coffee because you're worried about eating beforehand.

• You feel exhausted for the rest of the day after exercising rather than feeling refreshed or energised.

• Your workouts feel much harder than they used to, even though you're training consistently.

• You don't feel like you're getting any stronger, faster or fitter despite putting in the effort week after week.

• You never seem to experience that post-workout endorphin rush that other people talk about.

• You're constantly sore or still recovering when it's time for your next workout.

• You find yourself craving sugary foods later in the day or feeling ravenous after exercise.

• You avoid increasing the intensity of your workouts because you simply don't have the energy.

• Exercise feels like something you have to get through rather than something you genuinely enjoy.

If you found yourself nodding along to several of those, don't panic. None of these symptoms prove that you're under-fuelling, and there may be other explanations - poor sleep, iron deficiency, low vitamin D, chronic stress, certain medications and the hormonal changes associated with PMOS can all affect your energy levels and recovery too.

What they do tell me is that it's worth taking a closer look at how you're fuelling your body around exercise before assuming you simply need more motivation or a tougher training plan. One of the reasons this matters is because low energy availability - where the body doesn't have enough energy left over to support normal physiological processes after exercise - has been associated with poorer recovery, reduced training adaptations, impaired immune function and hormonal disturbances in active individuals (Mountjoy et al., 2023).

The complete guide, in four parts

I've broken this guide down into four shorter pieces so you can go straight to what you need, or read through the whole series:

→ Should You Eat Before Exercise with PMOS? The Insulin Resistance Question - the science behind why eating carbohydrate before a workout doesn't undo your progress.

→ What to Eat Before a Workout with PMOS - how much you actually need, and what that looks like whether you train in the morning or after work.

→ What to Eat After a Workout with PMOS (And Why Recovery Matters) - the two nutrients that matter most for recovery, and simple snack and meal ideas.

→ 3 Exercise Nutrition Myths Women with PMOS Should Stop Believing - fasted cardio, protein shakes, and the fear that eating around exercise will undo your hard work.

Your quick guide to fuelling exercise with PMOS

If you only take one thing from this guide, let it be this table.

If you're...	Before exercise	After exercise
Going for a gentle walk or doing an easy Pilates class	If you've eaten within the last couple of hours, you probably don't need anything extra.	Simply carry on with your normal meal pattern.
Strength training for around 45–60 minutes	If it's been more than 2–3 hours since your last meal, aim for around 20–40g carbohydrate before training.	Aim for 20–30g protein and 30–60g carbohydrate within the next couple of hours.
Playing football, netball, tennis or another high-intensity sport	A carbohydrate-rich snack around 60–90 minutes beforehand will often help you perform and feel better.	Replace both carbohydrate and protein afterwards to support recovery.
Exercising first thing in the morning	If it's more than a gentle walk, even a small snack such as a banana, toast or cereal can make a real difference.	Eat a balanced breakfast containing both carbohydrate and protein.
Exercising after work	If lunch was several hours ago, have a snack before you leave work rather than waiting until dinner.	If dinner is within the next hour, that's your recovery meal. If not, have a recovery snack first.

The bottom line

One of the biggest shifts I'd love to see is women with PMOS moving away from thinking of exercise as something that simply burns calories and food as something that needs to be earned.

Exercise is a stress on the body, but it's a positive one. Every time you ask your muscles to lift, run, jump or cycle, you're asking them to adapt. You're asking them to become stronger, fitter and more resilient. The only way they can do that is if you give them the energy and nutrients they need to recover afterwards.

That doesn't mean eating perfectly. It doesn't mean counting every gram of carbohydrate or protein. And it certainly doesn't mean buying expensive sports supplements.

Your goal shouldn't be to eat as little as possible around exercise. Your goal should be to fuel your body well enough that exercise feels enjoyable, your recovery feels easier and you're able to keep showing up consistently.

For many women with PMOS, that shift doesn't start with exercising harder. It starts with eating enough to support the exercise you're already doing.

If you're not sure whether under-fuelling, insulin resistance or something else entirely is behind how you've been feeling, that's exactly what we untangle together in an Initial Assessment and Roadmap. You'll leave with a personalised understanding of what's actually going on and a clear plan for what to focus on first.