Nutrition

HOW TO SAFELY EXERCISE YOUR GUT

Words: Benedict Freudenmann

Although stretching your gut to make room for that last slice of pizza could technically be construed as an exercise, it’s unfortunately not what I’m here to talk about today. I’m talking about the impact of physical exercise on your gut health.

Your gut isn’t just there to absorb nutrients from our food. It’s a major part of our immune system - did you know you have a whole miniature world living within your large intestine? It’s an ecosystem made up of bacteria, yeast, protozoa, viruses and other microbes. This ecosystem (called the microbiome) is completely reliant on our diet, body and lifestyle for survival. In turn, these helpful critters perform a range of essential functions for our digestion, mental health, immune system and overall health.

Recently the gut microbiome has been dubbed one the biggest modifiable factors or our overall health. These little bacteria are big news and we’re still learning more about them every day.

So why am I writing an article on safe exercise and gut health? We have so much incredible scientific data showing that exercise helps the gut, the bacteria within and your overall health. However did you know that approximately 30% of all endurance athletes have issues with their gut health?

So why is this?

The gut and brain are connected with the Vagus nerve - a two directional street which allows the gut to communicate with the brain and vice versa. Yet when the body detects enough stress, it shuts down this road. Stress can come in many forms, both physical and mental. When the stress is sufficient enough the brain shuts down the gut as it’s deemed as a non-essential organ for your survival. Instead it focuses on the heart, lungs, muscles and brain.

During this stressed state (sympathetic nervous system dominance) the gut rapidly starts losing blood flow. After 10 minutes of running it has lost up to 20% of its blood supply and after 60 minutes up to 80% is gone. This lack of blood flow to the gut has disastrous effects on the cells within the gut, the microbiome, our nutrient absorption and our bowel motions. This results in IBS like symptoms, diarrhoea, constipation, food intolerances, nutrient deficiencies and much more. So how can we have this amazing data showing us we should be exercising for our gut health and other data showing us it’s harmful? Our body has a tolerance. When we conduct exercise that’s too strenuous (over 70% maximum exertion) we negatively affect the gut, however any exercise conducted under 60% of maximum exertion has a profoundly positive effect on the gut and our entire bodies.

Now before you wind back your exercise to a mere gentle walk there’s plenty we can do to minimise these negative effects.

Hydration was critical in delaying any damage to the gut. Even a 10% reduction in hydration made a noticeable difference. Therefore make sure to stay fully hydrated. Eating (carbohydrates or sugars) during intense endurance exercise distracts the gut and can increase blood flow, thereby reducing damage brought on by lack of blood flow. Fruit is an excellent option for this. Finally there are a range of supplemental products which can help protect your gut from exercise induced damage. Discuss these with your nutritionist, dietician or doctor.

Exercise is essential for every facet of our wellbeing. However even something as great as exercise can have negative effects if overdone. If you’re an athlete who has digestive complaints, chat to a nutritionist to see if you can implement a program that works for your body and your sport.

Do you know your vitamin D status?

Vitamin D has so many functions within the body, it’s commonly referred to as a hormone. It’s essential for bone strength, your immune system, blood sugar control, inflammation, replication of DNA and supporting your mood and nervous system. After winter, 66% of Tasmanians are vitamin D deficient. Check with your GP whether testing vitamin D may be relevant to you.

Benedict is a clinical nutritionist who practices at www.learntonourish.com in Ranelagh.