Finding the Right Exercise Intensity for IBS

Exercise has a positive impact on the gut and seems to benefit IBS symptoms – but the intensity of exercise matters.

Intensity matters

Exercise intensity describes how hard the body is working during exercise. It's gauged by measuring heart rate, or by how hard you feel you're working during the exercise.

Compare how you feel during a walk (which is usually low intensity) with running as fast as you can (high intensity).

Research shows that as exercise intensity increases, so do gut symptoms like nausea, diarrhea and stomach cramps. In a 2008 study of over 1200 athletes, 45% experienced at least one gut symptom, but depending on the sport studied, it can be as much as 93%.

How does intense exercise lead to gut symptoms?

When we exercise, blood flow to the gut reduces, and moves towards the working muscles (to provide oxygen and nutrients) and skin (to dissipate heat). During high intensity exercise (when you’re putting in as much effort as you can), blood flow to the gut reduces by as much as 80 per cent.

This can lead to symptoms like nausea, cramps and diarrhea. With less blood flow digestion slows down too, which is why you might experience cramps if you exercise too soon after eating.

Dehydration, training in the heat and the jostling of your gut (think about your gut bouncing up and down when running!) play a role in discomfort too. So as a general guide, low to moderate intensity is best for supporting gut health.

What counts as moderate intensity? 

A good rule of thumb is to use the talk test - if you're exercising and can still hold a conversation, then you're working at moderate intensity.

Think about going for a walk or jogging and being able to chat to a friend who is jogging with you.  If you struggle to talk (an example being when going hell for leather in a spin class or sprinting for a bus) then you’re in the intense zone.  

Does this mean I can’t do tough workouts?

If you feel fine during and after higher intensity workouts, then feel free to continue. Planning regular rest days between workouts will help your gut to recover.

If you think high intensity exercise aggravates your IBS symptoms, switch to lower intensity for a couple of weeks and see if symptoms ease.

If you’re new to exercise or building up your activity levels, make moderate intensity exercise your go-to.

Top tips for embracing exercise when you have IBS:

* Easy Does It: Keep it gentle with low to moderate intensity exercise. Brisk walking, riding a bike, dancing, and swimming all count. Anything which gets you warm and raises your heart rate!

* Listen to Your Body: If your usual workouts are intense, consider dialling it down a notch. Give yourself some rest days between the tougher sessions. Your body will thank you.

* Regular Rendezvous: Aim for 30 minutes of activity most days of the week. Put your workouts in your diary to make a habit of them.

* Fun Matters: Find exercise that you enjoy. Whether it's a walk, a dance, or a yoga session, choose what makes you happy. If you enjoy exercise, you’ll find it easier to stick with it.