Whilst diet and supplements remain to be an effective means of patching up a leaky gut, the subtle yet profound effects of exercise often get overlooked.
After all, exercise does exhibit pretty big changes to your physiology, influencing the communication network of neurotransmitters, hormones and immune messengers throughout your body.
When a stimulus like exercise is applied, it can work some real magic within if you do it on the reg and in certain ways.
This is particularly significant because a hallmark of leaky gut is the fact that the cells of the intestinal lining become damaged, inflammation is at play, and some hormones may also be going rogue.
Thats not good news for intestinal integrity and systemic health as dietary antigens, bacterial fragments and microbial metabolites can sneak through damaged cells and between them.
The balance with exercise is a delicate one – the intensity, duration and type can be the difference between helping or hindering a leaky gut.
Lets take a look at how strength training may be beneficial, and how you can reap these benefits.
One of the major driving forces resulting from, and perpetuating a lot of gut issues is inflammation. Whether it be a result of stress, overexposure to environmental toxicity or a standard western diet – it all comes down to inflammation.
Reducing your exposure to things that induce inflammation is one thing, actually fighting that fire is another. In other words, simply reducing your exposure to the above wont quite cut it.
The good news is there’s loads of ways to put out that inflammatory fire to allow some order to be re-established in the gut. Strength training being one of them.
Intensity is key here – whilst mild to moderate training tends to evoke anti-inflammatory responses (1), strenuous, lengthy, high volume training may increase systemic inflammation and pro-inflammatory messengers (2).
The balance is delicate, and moderate exercise has been found to be beneficial for Crohn’s patients up to a point of 75% Hr max (3), (4). It might be different for resistance training, but this might be a benchmark (as well as gauging how you and your gut feel).
Using appropriate levels of exercise stimulus (which I will cover below), you may alter the effects of inflammation. Let me elaborate.
During exercise, your muscles release another cytokine, IL-6, which is usually pro-inflammatory. But when stimulated by resistance training (8), it has a drastically different effect. IL-6 actually reduces the production of TNF-a (9), acting as a myokine.
Jan Bilskia Agnieszka Mazur-Bialya Bartosz Brzozowskib Marcin Magierowskic Janina Zahradnik-Bilskab Dagmara Wójcikc Katarzyna Magierowskac Slawomir Kwiecienc Tomasz Machb Tomasz Brzozowskic. Can exercise affect the course of inflammatory bowel disease? Experimental and clinical evidence. 2016.
Reducing inflammation helps break the cycle of intestinal damage, and may help improve nutrient absorption, permeability and subsequent GI symptoms.
When you train your muscles, you are also training your endocrine system. Stimulation of glands throughout the endocrine system is relative to the amount of bodily movement you do.
The benefits of whole body workouts are profound, because they often recruit the whole body. In particular types of training like cross fit, and weighted calisthenics, particular attention is paid to compound exercises which recruit large groups of muscles within one movement, like the back squat.
So you could almost think of your muscles as endocrine organs, given their profound regulatory capacity on the activity of hormones.
Commonly imbalances and deficiencies in key hormones like cortisol can be at play in digestive disorders, namely cortisol. Such as in IBS and IBD (10).
Food sensitivities, autoimmunity and allergies are associated with cortisol imbalances, and can ultimately complicate proper immune regulation (11).
In particular cases of cortisol insufficiency, light resistance training could help normalise cortisol. Cortisol has been found to increase after resistance training (12), and elevating cortisol from exercise stimuli as opposed to stress could actually be beneficial (13).
Lifting weights could also be beneficial for the cells in your gut via products released from muscles during and after muscular contraction.
IL-6 is just one of many myokines, and outside of exercise conditions, its presence is actually considered to be undesirable, because it is a pro-inflammatory cytokine.
However, in exercise IL-6 stimulates a hormone called GLP-1 (Glucagon like peptide) which initiates cell proliferation aka division, and apoptosis – the recycling of old and damaged cells. This means that GLP-1 stimulates the repair of the intestinal mucosa. (14).
GI System – Nervous System – Muscle
The nervous system has a profound regulatory capacity throughout the gastrointestinal system. You’ve probably heard of the brain gut connection, well this is its highway.
More of these highways are connected to skeletal muscles throughout your body. Because of this, the activity of your muscles can affect the status of your digestive system.
Again, much like the endocrine system, the synthesis, transmission and clearance of neurotransmitters significantly affects processes like gut motility, digestive enzyme secretion and hormonal signalling.
So by stimulating muscular contraction, you can directly influence the health of your gut.
Digestion operates at its finest when stimulated via the parasympathetic nervous system and the vagus nerve. A better tone, aka balance within this system prevents the sympathetic nervous system hijacking important processes like:
- Gastric acid secretion
- Motility/ transit time
- Digestive enzyme activity
These are the things that often go wrong upstream of and within the intestine.
Vagal tone is an important element of gut issues in both IBS & IBD, and its regulation affects inflammatory signalling, and further nervous signalling via adrenaline for instance (15).
This review analyses various studies on exercise therapy (calistenics, resistance training and aerobic exercise) and supports the idea that they may have a beneficial impact, through increased vagal tone and decreased sympathetic activity (16).
How To Train
All health begins in the gut, and of course if you have a gut thats going awal, its natural to see some loss in bone density, muscle mass and energy.
Resistance training is a fantastic way to not only target the areas we’ve discussed above, but also for actually improving measurable and more noticeable outcomes in your health.
Lifting weights is well documented in improving bone density, muscle mass and alleviating fatigue. (17)
- A good workout always starts with a 5 minute warm up, in order to mentally and physically prepare yourself for training. This way you prevent injury, dial in your focus and instruct your body that its go time.
- Keep it light to begin with and focus on whole body mobility exercises. Pay special attention to the lower extremities and torso.
- Working your largest muscle groups, legs in particular provide the greatest hormonal stimulus we looked at earlier.
- Aim for 2 sets of 10-12 repetitions for legs – say squats, and make this the main part of your session. Start at 50% 1 RM. Ensure you are gauging your intensity with how your gut feels throughout your workout, and reduce intensity if necessary.
- You can rest for 2-3 minutes in between sets to avoid overdoing it.
- Start using free weights, and shoot for around 5-8 reps at 50% of your 1 rep max.
1 rep max is measured as the most weight you can lift for 1 repetition. Once you know this, you can lift a fractional percentage of that weight for repeated reps.
As you begin to train more frequently, you can slowly increase the weight (maybe to 60% 1 RM), add another set in, add more reps and/or reduce your rest periods.
Training protocol sourced from Prescription of Physical Activity in Crohn’s Disease (18).
One of the core principles of exercise is overload, which is putting in just enough effort to induce a positive adaptation to training. Incrementally upping the difficulty of your workouts will ensure you are becoming stronger, not just muscularly, but your body as a whole.
Another principal of training is avoiding overtraining. Push it too much, and your gut could be aggravated or you may risk burning out. Try to balance your overload without overtraining.
You can do this by keeping track of your HRV.