Pre-workout supplements and IBS

Previously we have looked into low FODMAP protein powders, so sticking with the theme of supplements, we’re now going to take a look at pre-workout powders and why they may worsen your IBS symptoms.

Why can pre-workout supplements worsen symptoms?

This will vary depending on the specific pre-workout supplement. There are a few ingredients commonly found in pre-workout supplements that may provoke gut symptoms in susceptible individuals, even those without IBS. Symptoms include diarrhoea, nausea, constipation, stomach pain and flatulence.

Substances often used in pre-workout supplements include caffeine, creatine, carnitine, inulin and artificial sweeteners.  Why are these added?  Usually either for a proposed enhancement in exercise performance or in a claim to aid weight-loss/muscle gain.  Or in the case of inulin and sweeteners, the purpose is for improving flavour and consistency.

So are pre-workout supplements suitable for IBS sufferers?

The evidence supporting the use of pre-workout supplements is conflicting and limited.  Regardless of whether you suffer from IBS, the use of a pre-workout supplement is most likely unnecessary.  For those with IBS, pre-workout supplements are particularly not ideal due to their common gut side effects such as diarrhoea and nausea.

Now you may be thinking, how am I supposed to fuel my gym session now!?  Easy – save your cash and opt for food instead.  Let’s not forget that food = fuel!

Some low FODMAP pre-workout food options

There is no one-size-fits-all approach when it comes to the best pre-workout food.  It depends on your food preferences, what time you eat vs what time you exercise, what sort of exercise you will be doing and so on.  If you are going to have a larger meal, it's generally best to consume this 3 - 4 hours before exercising to avoid any discomfort.  If you choose to have a smaller meal or snack, having this 1-2 hours before exercise is a good option.  Here are some different low FODMAP pre-workout food options:

• Overnight oats. Soak oats in lactose-free milk or almond milk overnight then top with some lactose-free yoghurt and banana/berries.
• Peanut butter and sliced banana on toast or rice cakes.
• Fruit smoothie. Frozen berry and banana are great low FODMAP options.  Smoothies are great for those who can’t stomach food before workouts.
• Coffee – just be mindful of quantity (see article on coffee and IBS). Most people with IBS should be able to tolerate at least 1 cup of coffee each day.
• Chicken and salad gluten-free wrap
• Basil and soy stir-fry (either meat or tofu) with veggies + basmati rice.
• Jacket potato. Roast or boil a medium potato and top with your favourite filling e.g low FODMAP bolognaise mince.

As a whole – go for something which contains carbohydrates (e.g grains, cereal, fruit) and is not high in fat/fibre (this can cause gut discomfort during exercise). Usually, a bit of trial and error is involved before you find the pre-workout food that works best for you.

Need help with the low FODMAP diet? Our FREE dietitian developed program will guide you through it, step-by-step. Includes a low FODMAP food guide. Sign up now.

If you are experiencing gut symptoms and have not been recommended a low FODMAP diet by a health professional, get started with the manage your gut symptoms program.

Reviewed by the healthylife Advisory Board March 2022