If there is one thing that yoga teachers & dietitians have in common – it’s love for a good digestive moment!
Dietitians love a healthy bowel movement, and as a yoga teacher, I love a twisty, fiery, core-intensive flow! Which is exactly what this video is: a short yoga sequence to help stimulate digestion. This sequence uses a combination of gentle pressure, belly breathing, twisting, alignment, activation, and relaxation to encourage feelings of ease within the belly.
Now to get a little more technical: We eat. We excrete.
It’s a seemingly simple relationship, but the symphony of processes facilitating our digestion is incredibly complex. While this video can help you identify and activate the muscles cushioning the digestive system, there are numerous enzymes, hormones, and nerve signals working behind the scene to help you break down your food and move it through your system!
When we eat, food enters our body. Once inside, food needs to be broken down into its smallest components so that our cells can use it for energy and bodily functions. Carbohydrates are broken down into smaller sugars, proteins into amino acids, and lipids into fatty acids. From there, sugars, amino acids, and fatty acids enter their unique pathways to continue the breakdown process into atoms of (mainly) carbon, hydrogen, nitrogen, and oxygen, producing energy (in the form of ATP) in the process.
The digestive system is a series of organs designed to move nutrients into the body. It works along side the endocrine, nervous, urinary, and integumentary (hair, nails, and skin) systems to provide our bodies with efficient elimination of waste products. The main structure of the digestive system is the Gastrointestinal (GI) tract, which spans about 10 metres in length from the mouth to the anus. The GI tract includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.
In a healthy adult, transit time through the GI tract is about 24-72 hours, with the majority of the time being spent in the large intestine (24 hours on average). However, transit time can be impacted by many things including the composition of your diet, physical activity level, emotional state, medications, and ongoing illnesses.
The process of digestion is both chemical and physical. Beginning before we even ingest anything, the sight, smell, and even sound (think sizzling onions and garlic in a pan) of food begin to increase GI motility and saliva excretions. Once we’ve taken our first bite of something, we chew and gnash with the tongue and the teeth as saliva (which contains salivary amylase) begins to break down carbohydrates into smaller sugars (di- and polysaccharides). The process of chewing forms the food into a small “packet” of food and saliva called a bolus, which will proceed down the pharynx when swallowed.
After passing through the pharynx rather uneventfully, the bolus enters the esophagus where a rhythmic muscular contraction (think ocean waves) called peristalsis begins to propel the bolus downwards towards the stomach. This process is so strong that it would persist even if you were standing on your head!
The bolus (a truly cringe-worthy word) finally reaches the stomach, which media and conjecture would have us believe is the pinnacle point of digestion! While it is important, the fact is that most of our digestion actually takes place in the small intestine, and the stomach is more of a temporary storage unit. In the stomach, a hormone called gastrin triggers the release of delicious-sounding “gastric juice” (Recipe: Hydrochloric acid, intrinsic factors, pepsinogen, and in children, rennin). This acidic gastric juice temporarily stops the digestion of carbohydrates and shifts the focus to proteins and lipids.
Next, the mixture of food and gastric juice (a combination known as chyme) moves into the small intestine. The amount of time spent in the stomach varies based on the nutritional composition of the meal, but can be anywhere from 2-6 hours.
- A meal that is larger, mostly solid, and high in fat will take longest to leave the stomach.
- A meal that is smaller, more liquid, and higher in protein or carbohydrates will leave the stomach faster.
- A high carbohydrate, low fat meal will leave the stomach the fastest and have you feeling hungry more quickly.
The small intestine is the main site of digestion and absorption. Due to the billions of microvilli (small, fingerlike projections on the lining of the small intestine), the surface area of this organ is about the size of a tennis court. Secretions from the pancreas and gall bladder neutralize the acidic chyme with bicarbonate ions, which signals the pancreas to release an army of enzymes: pancreatic amylase for carbohydrates, lipase for lipids, and trypsin for proteins. Simultaneously, the gall bladder summons its secret weapon: bile. Bile is necessary for the breakdown and absorption of fatty acids.
In the small intestine, nutrients, water, vitamins, and minerals are absorbed via osmosis, simple diffusion, facilitated diffusion, and active transport. What remains after the extensive absorptive process is passed along to the large intestine. The undigested/unabsorbed material takes its time, spending about 24 hours to move through the large intestine, colon, and rectum. This allows more water and minerals to be absorbed, and also lets the colonies of microflora that reside in your large intestine to feed off the undigested fibre that remains. Our large intestine contains 300-500 species of bacteria that can utilize some of the undigested matter for themselves, producing useful fatty acids, some B vitamins, and vitamin K as byproducts. A fun (or bothersome, depending on your perspective) side effect of these helpful bacteria is that they release gas (aka. farts). A normal adult produces between 200mL and 2000mL per day!
Material that cannot be absorbed or utilized in the large intestine is excreted as feces. Approximately 50% of the weight of our feces is bacteria (depending on how much water and fibre you consume). Often, when individuals do not consume enough fibre and water, they become constipated. If constipation is the digestive issue that brought you to this video/blog post, I suggest having a fibre-rich snack (a piece of fruit or some vegetables), grabbing a glass of water, and moving through this video. Research has shown that gentle movement can help with constipation.
I wanted to go through this background information to make it clear that yoga isn’t the secret key to great digestion, but merely a tool to assist by providing movement and relaxation. The body is already doing a lot to keep itself high-functioning, but digestive issues remain extremely common. In addition to keeping your stress levels balanced and enjoying a daily moving practice (hello, yoga!), including water, fibre, and fermented products (sauerkraut, kimchi, yogurt, kefir) can help keep your gut happy and healthy.
Roll out your mat, press play on the “Yoga for Digestion” video, and let’s get flowing!