Western science is starting to provide some concrete clues as to how yoga works to improve health, heal aches and pains, and keep sickness at bay. Once you understand them, you'll have even more motivation to step onto your mat.
1. Improves your flexibility
Improved flexibility is one of the first and most obvious benefits of yoga. During your first class, you probably won't be able to touch your toes, never mind do a backbend. But if you stick with it, you'll notice a gradual loosening, and eventually, seemingly impossible poses will become possible. You'll also probably notice that aches and pains start to disappear. That's no coincidence. Tight hips can strain the knee joint due to improper alignment of the thigh and shinbones. Tight hamstrings can lead to a flattening of the lumbar spine, which can cause back pain. And inflexibility in muscles and connective tissue, such as fascia and ligaments, can cause poor posture.
2. Builds muscle strength
Strong muscles do more than look good. They also protect us from conditions like arthritis and back pain, and help prevent falls in elderly people. And when you build strength through yoga, you balance it with flexibility. If you just went to the gym and lifted weights, you might build strength at the expense of flexibility.
3. Perfects your posture
Your head is like a bowling ball—big, round, and heavy. When it's balanced directly over an erect spine, it takes much less work for your neck and back muscles to support it. Move it several inches forward, however, and you start to strain those muscles. Hold up that forward-leaning bowling ball for eight or 12 hours a day and it's no wonder you're tired. And fatigue might not be your only problem. Poor posture can cause back, neck, and other muscle and joint problems. As you slump, your body may compensate by flattening the normal inward curves in your neck and lower back. This can cause pain and degenerative arthritis of the spine.
4. Prevents cartilage and joint breakdown
Each time you practice yoga, you take your joints through their full range of motion. This can help prevent degenerative arthritis or mitigate disability by "squeezing and soaking" areas of cartilage that normally aren't used. Joint cartilage is like a sponge; it receives fresh nutrients only when its fluid is squeezed out and a new supply can be soaked up. Without proper sustenance, neglected areas of cartilage can eventually wear out, exposing the underlying bone like worn-out brake pads.
5. Protects your spine
Spinal disks—the shock absorbers between the vertebrae that can herniate and compress nerves—crave movement. That's the only way they get their nutrients. If you've got a well-balanced asana practice with plenty of backbends, forward bends, and twists, you'll help keep your disks supple.
It's well documented that weight-bearing exercise strengthens bones and helps ward off osteoporosis. Many postures in yoga require that you lift your own weight. And some, like Downward- and Upward-Facing Dog, help strengthen the arm bones, which are particularly vulnerable to osteoporotic fractures. In an unpublished study conducted at California State University, Los Angeles, yoga practice increased bone density in the vertebrae. Yoga's ability to lower levels of the stress hormone cortisol may help keep calcium in the bones.
7. Increases your blood flow
Yoga gets your blood flowing. More specifically, the relaxation exercises you learn in yoga can help your circulation, especially in your hands and feet. Yoga also gets more oxygen to your cells, which function better as a result. Twisting poses are thought to wring out venous blood from internal organs and allow oxygenated blood to flow in once the twist is released. Inverted poses, such as Headstand, Handstand, and Shoulderstand, encourage venous blood from the legs and pelvis to flow back to the heart, where it can be pumped to the lungs to be freshly oxygenated. This can help if you have swelling in your legs from heart or kidney problems. Yoga also boosts levels of hemoglobin and red blood cells, which carry oxygen to the tissues. And it thins the blood by making platelets less sticky and by cutting the level of clot-promoting proteins in the blood. This can lead to a decrease in heart attacks and strokes since blood clots are often the cause of these killers.
8. Drains your lymphs and boosts immunity
When you contract and stretch muscles, move organs around, and come in and out of yoga postures, you increase the drainage of lymph (a viscous fluid rich in immune cells). This helps the lymphatic system fight infection, destroy cancerous cells, and dispose of the toxic waste products of cellular functioning.
9. Drops your blood pressure
If you've got high blood pressure, you might benefit from yoga. Two studies of people with hypertension, published in the British medical journal The Lancet, compared the effects of Savasana with simply lying on a couch. After three months, Savasana was associated with a 26-point drop in systolic blood pressure (the top number) and a 15-point drop in diastolic blood pressure (the bottom number—and the higher the initial blood pressure, the bigger the drop.
10. Regulates your adrenal glands
Yoga lowers cortisol levels. If that doesn't sound like much, consider this. Normally, the adrenal glands secrete cortisol in response to an acute crisis, which temporarily boosts immune function. If your cortisol levels stay high even after the crisis, they can compromise the immune system. Temporary boosts of cortisol help with long-term memory, but chronically high levels undermine memory and may lead to permanent changes in the brain. Additionally, excessive cortisol has been linked with major depression, osteoporosis (it extracts calcium and other minerals from bones and interferes with the laying down of new bone), high blood pressure, and insulin resistance. In rats, high cortisol levels lead to what researchers call "food-seeking behavior" (the kind that drives you to eat when you're upset, angry, or stressed). The body takes those extra calories and distributes them as fat in the abdomen, contributing to weight gain and the risk of diabetes and heart attack.
11. Makes you happier
Feeling sad? Sit in Lotus. Better yet, rise up into a backbend or soar royally into King Dancer Pose. While it's not as simple as that, one study found that a consistent yoga practice improved depression and led to a significant increase in serotonin levels and a decrease in the levels of monoamine oxidase (an enzyme that breaks down neurotransmitters) and cortisol. At the University of Wisconsin, Richard Davidson, Ph.D., found that the left prefrontal cortex showed heightened activity in meditators, a finding that has been correlated with greater levels of happiness and better immune function. More dramatic left-sided activation was found in dedicated, long-term practitioners.
12. Helps you sleep deeper
Stimulation is good, but too much of it taxes the nervous system. Yoga can provide relief from the hustle and bustle of modern life. Restorative asana, yoga nidra (a form of guided relaxation), Savasana, pranayama, and meditation encourage pratyahara, a turning inward of the senses, which provides downtime for the nervous system. Another by-product of a regular yoga practice, studies suggest, is better sleep—which means you'll be less tired and stressed and less likely to have accidents.
13. Boosts your immune system functionality
Asana and pranayama probably improve immune function, but, so far, meditation has the strongest scientific support in this area. It appears to have a beneficial effect on the functioning of the immune system, boosting it when needed (for example, raising antibody levels in response to a vaccine) and lowering it when needed (for instance, mitigating an inappropriately aggressive immune function in an autoimmune disease like psoriasis).
14. Prevents IBS and other digestive problems
Ulcers, irritable bowel syndrome, constipation—all of these can be exacerbated by stress. So if you stress less, you'll suffer less. Yoga, like any physical exercise, can ease constipation—and theoretically lower the risk of colon cancer—because moving the body facilitates more rapid transport of food and waste products through the bowels. And, although it has not been studied scientifically, yogis suspect that twisting posesmay be beneficial in getting waste to move through the system.
15. Gives you peace of mind
Yoga quells the fluctuations of the mind, according to Patanjali'sYoga Sutra. In other words, it slows down the mental loops of frustration, regret, anger, fear, and desire that can cause stress. And since stress is implicated in so many health problems—from migraines and insomnia to lupus, MS, eczema, high blood pressure, and heart attacks—if you learn to quiet your mind, you'll be likely to live longer and healthier.
16. Eases your pain
Yoga can ease your pain. According to several studies, asana, meditation, or a combination of the two, reduced pain in people with arthritis, back pain, fibromyalgia, carpal tunnel syndrome, and other chronic conditions. When you relieve your pain, your mood improves, you're more inclined to be active, and you don't need as much medication.
17. Gives you inner strength
Yoga can help you make changes in your life. In fact, that might be its greatest strength. Tapas, the Sanskrit word for "heat," is the fire, the discipline that fuels yoga practice and that regular practice builds. The tapas you develop can be extended to the rest of your life to overcome inertia and change dysfunctional habits. You may find that without making a particular effort to change things, you start to eat better, exercise more, or finally quit smoking after years of failed attempts.
18. Helps keep you drug free
If your medicine cabinet looks like a pharmacy, maybe it's time to try yoga. Studies of people with asthma, high blood pressure, Type II diabetes (formerly called adult-onset diabetes), and obsessive-compulsive disorder have shown that yoga helped them lower their dosage of medications and sometimes get off them entirely. The benefits of taking fewer drugs? You'll spend less money, and you're less likely to suffer side effects and risk dangerous drug interactions.
19. Keeps allergies and viruses at bay
Kriyas, or cleansing practices, are another element of yoga. They include everything from rapid breathing exercises to elaborate internal cleansings of the intestines. Jala neti, which entails a gentle lavage of the nasal passages with salt water, removes pollen and viruses from the nose, keeps mucus from building up, and helps drains the sinuses.
20. Supports your connective tissue
As you read all the ways yoga improves your health, you probably noticed a lot of overlap. That's because they're intensely interwoven. Change your posture and you change the way you breathe. Change your breathing and you change your nervous system. This is one of the great lessons of yoga: Everything is connected—your hipbone to your anklebone, you to your community, your community to the world. This interconnection is vital to understanding yoga. This holistic system simultaneously taps into many mechanisms that have additive and even multiplicative effects. This synergy may be the most important way of all that yoga heals.