Is exercise good for the gut?
We know that regular exercise is good for health, but is it good for the gut? Exercise can be beneficial to IBS symptoms as it can stimulate the natural squeezing of muscles in the intestines. This squeezing can help speed up ‘transit time’ – the time it takes for food to navigate its way through your gut. Speeding up transit time can be helpful in relieving constipation and bloating. Exercise also releases endorphins, leading to a greater sense of calm and wellbeing. We know that stress also plays a role in IBS symptoms, so exercise can have a ‘double whammy’ effect on both stimulating muscle movement and reducing stress.
The key to navigating exercise with IBS is understanding how different intensities of exercise can affect the gut, so we will go through this today.
The effects of gentle exercise on the gut
When suffering from IBS symptoms, exercise should aim to move our bodies in a gentle and comfortable way. We want to help our symptoms, not make them worse! Low impact exercise such as walking, yoga, light cycling, tai chi or swimming are all activities that can help reduce stress while improving fitness.
Yoga has been shown to be particularly beneficial in patients with IBS.1 There is even evidence to suggest that a regular hatha yoga practice is as effective of an intervention as the low FODMAP diet! 2 Yoga typically address both the mind and body, and some movements are helpful in enhancing energy circulation in and around the intestines. Also, due to the focus on deep breathing during a yoga class, the parasympathetic nervous system (the rest, digest and repair arm of our autonomic nervous system) is activated. Therefore, yoga can be helpful in addressing both muscle movement around the intestines and stress reduction.
The effects of vigorous exercise on the gut
Intense training that involves a lot of jumping may make people with painful gut symptoms even more uncomfortable, particularly if the abdomen is distended or there is a lot of gas in the bowel.
While gentle exercise helps direct blood flow to the gut and stimulate muscle contraction around the intestines, intense exercise naturally diverts blood away from the gut to our arms and legs – because this is where we need the blood to be pumping if we want to run, jump and lunge. Additionally, even though we aren’t under ‘stress’ in the way we may typically think of the word, our body is under physical stress during vigorous exercise.
When we exercise at high intensities, the digestive system receives less blood flow because the blood is being diverted to other important areas of the body involved in exercise. Symptoms of this decreased blood flow include a gurgly stomach, cramps and loose bowels which can lead to frequent stools. Runners colitis is the term for the group of diarrhoea-related symptoms brought on by intense exercise. Prolonged colitis can lead to increased perforation in the gut lining, so it is important to seek medical advice if you think you might be experiencing runner’s colitis.
Does having IBS mean I need to avoid strenuous activity altogether?
Not necessarily! ‘Strenuous’ exercise is a subjective concept. For example, if you enjoy running, you shouldn’t necessarily stop doing it unless you think that running may be causing problems. If it does, you could consider pulling back either the time, intensity or type of training. Also, remember that IBS symptoms can occur in both athletes and non-athletes, however symptoms can be exacerbated in exercise, particularly the urgency to find a bathroom while running.
What about exercise for high performance athletes?
High-intensity, vigorous exercise can generally lead to gastrointestinal distress even for those without IBS. Further, it may also trigger symptoms in those with IBS. We see this commonly in high performance athletes, particularly when exercising in hot temperatures and if the body becomes dehydrated. In long distance/intense bouts of exercise, blood flow to the gastrointestinal system can be reduced by as much as 80%. Substantial dehydration can be part of the problem with gut issues, as it can reduce blood volume and further reduce blood flow to the gut. In the long term, this can compromise gut function and could lead to bowel perforation.
It is important that as an athlete, you work with a sports dietitian who can help you navigate your athleticism with IBS symptoms. Experiencing regular digestive symptoms can be stressful and impact on your confidence and performance. Additionally, those prone to nervous anxiety are more commonly affected by stress-related gut disturbance. Therefore, working also with a sports-psychologist can help to manage anxieties around performance and help to reduce stress-related gut symptoms.
How frequently should I be moving?
It is beneficial for the body to move every day, so the more walking and incidental exercise you can do, the better. If you’re not currently active, start small and gradually increase your activity to see how you feel. Experiment to find what works best for you.
Physical activity guidelines for adults echo the message that we should try being active on most, if not all days of the week. 150-300 minutes of moderate intensity activity is recommended per week. What does this look like? 30 minutes of moderate activity five times a week would get you to the 150-minute line.
The key to exercising effectively with IBS is being mindful of the intensity. Exercising at a moderate intensity tends to be far more effective in managing IBS symptoms than either sitting in a chair or exercising vigorously.
- Kavuri V, Selvan P, Malamud A, Raghuram N et al. Remedial yoga module remarkably improves symptoms in irritable bowel syndrome patients: A 12-week randomized controlled trial. European Journal of Integrative Medicine; 2015 7(6). p. 595-608
- Schumann, D, Langhorst, J, Dobos, G, Cramer, H. Randomised clinical trial: yoga vs. a low‐FODMAP diet in patients with irritable bowel syndrome. Alimentary Pharmacology & Therapeutics. 2018; 47. p. 203– 211
Written by: Charlotte Barber (Student Nutritionist)
Reviewed by: Charmaine Duong (Dietitian)
