Yoga is a meditative practice in motion originated in the ancient Indian religion and tradition. While it started as a spiritual practice, currently there are many scientific studies that confirm the health benefits of yoga. These benefits include increased HRV, increased BDNF, and reduced oxidative stress. Yoga can also help manage chronic diseases like cancer and multiple sclerosis. Read this post to learn more about the science-backed mechanisms that explain why yoga is beneficial and the 19 health benefits of yoga that are backed up by clinical studies.
What is Yoga?
Yoga is a meditative practice in motion with its roots going back to ancient India. Yoga is a Sanskrit word which means union. It combines physical postures, deep breathing techniques, meditation, and relaxation.
There are many different forms of yoga, including Hatha, Pranayama, Ashtanga Vinyasa, Kundalini, Bikram, etc.
Hatha yoga focuses on physical and mental strength building poses. Many westernized types of Hatha Yoga are used today to improve overall health and wellbeing.
One variation of Hatha yoga is Iyengar, which focuses on the detail, precision, and alignment of the posture and breath control. It helps developing stability, strength, and stamina .
Another Hatha variation, called Pranayama, is also known as breathing exercises that benefit your entire body. Pranayama has shown to increase the blood flow and release of toxins from the body. Releasing toxins through deep breathing has shown to promote better sleep .
Ashtanga Vinyasa yoga is a physically demanding yoga practice that involves sequences of yoga postures that are synchronized with the breath. It is physically more demanding than other types of yoga .
On the other hand, Kundalini Yoga includes many meditation techniques. It is mostly used as a tool to treat anxiety disorders or for meeting mental challenges .
Bikram yoga is an intense type of yoga that is practiced in a room heated to 105 °F with 40% humidity. Although it can improve strength and balance in healthy adults, beginners should be careful due to its intense nature .
Yoga Nidra, also called yogic relaxation therapy, is a form of gentle yoga that typically comprises of maintaining a shavasana pose (corpse pose or simply laying comfortably) and guided meditation .
Health Benefits of Yoga
1) Improves Heart Rate Variability and Vagus Nerve Tone
The vagus nerve plays an important role in all aspects of health. Read this post to learn more about the vagus nerve.
Yoga can stimulate the vagus nerve by movement, chanting, and breathing exercises. The vagus nerve stimulation may be responsible for some of the positive effects that the yoga practice has on the brain and emotions .
By stimulating the vagus nerve, yoga increases the parasympathetic nervous system (PNS) activity. The increased PNS activity results in an increase of γ-Aminobutyric acid (GABA) levels in the brain .
Yoga can increase heart rate variability (HRV) and vagus nerve tone .
Note: HRV is used for health and fitness and is an indicator of autonomic regulation and vagus nerve health. High HRV is associated with fitness, strength, and resilience to stress.
2) Reduces Stress
Yoga includes meditation, relaxation, and exercise. It helps control stress response systems, thus reducing stress and anxiety. Yoga reduces heart rate, improves breathing, and lowers blood pressure. All of these effects help control the HPA axis and sympathetic nervous system, thus reducing stress , which positively affects overall health.
Yoga practice successfully reduced stress among students with high workloads and increased their overall perception of joy .
3) Helps Reduce Oxidative Stress and Increase Cellular Antioxidants
Several small-scale studies in diverse subject types (e.g., Air Force Academy trainees, healthy young men, university students, and menopausal women) have consistently shown that yoga helps reduce oxidative stress.
- decreased oxidized glutathione levels
- decreased nitric oxide levels
- decreased lipid peroxides levels
- increased total glutathione levels
- increased antioxidant enzymes, such as glutathione peroxidase
4) Increases Cognitive Function
There are many ways that yoga may help with cognitive function, such as:
- increasing BDNF 
- activating the vagus nerve 
- reducing oxidative stress and inflammation
- reducing the response to stress
Yoga may increase cognitive function by activating the default mode network (DMN), the part of the brain that is active when the individual is not focused inward to the self and not to the outside world (e.g., during yoga or meditation). Increased DMN function has been associated with improved memory performance in young adults and executive-function tasks in older adults [15, 16].
5) Helps with Pain from Chronic Illnesses
Patients who suffer from chronic back pain, fibromyalgia, osteoarthritis, neck pain, or severe migraines and do not wish to take conventional painkillers find that yoga and similar practices have pain-relieving effects when done correctly .
Patients with fibromyalgia showed improved strength, balance, and pain tolerance during yoga therapy and 3 months after treatment .
Women suffering from pelvic pain many times do not find relief through normal channels. Yoga can help alleviate pelvic pain and reduce the stress and anxiety that women get from this kind of pain .
In patients who have become addicted to opiate painkillers, pain relief during withdrawal is relieved by group medical visits and yoga therapy. Over time, the opiate need disappears, and pain relief can be handled with yoga .
6) Reduces Inflammation
Regular practice can reduce cytokine levels and protect against inflammation .
7) Helps with Weight Loss and Cardiovascular Health
In a meta-analysis that included 2173 participants from 30 clinical trials, yoga as an intervention was effective for weight loss in terms of BMI but not in terms of body fat or waist circumference in overweight/obese subjects. However, yoga had no significant effect on any of these parameters in normal weight people . Therefore, yoga alone may not be an effective way of reducing weight or body fat. However, by reducing stress and inflammation, it can be beneficial in other ways when combined with diet and increased physical exercise.
There are many ways in which yoga helps with weight loss as part of a lifestyle intervention program including:
By reducing stress, yoga reduces inflammation, which may help with leptin sensitivity .
Reducing Inflammation and Increasing Adiponectin
Inflammation can cause obesity. Yoga can reduce inflammatory cytokines and adipokines such as IL-6, IL-18, TNF-alpha, and CRP, and increase adiponectin in obese and post-menopausal women .
Improving Cardiorespiratory Fitness
8) Improves Multiple Sclerosis Symptoms
Integrated yoga and physical therapy improve auditory and visual reaction time while reducing depression and anxiety symptoms in patients with multiple sclerosis (MS) .
- improving cognitive dysfunction disabilities in patients with MS 
- improving mood 
- increasing physical and emotional functions
- increasing energy levels and reducing fatigue
- improving overall hygiene
- reducing pain and hospitalization time due to MS symptoms 
- increasing strength and balance
- increasing lower limb strength and core balance, thus helping with gait and walking capabilities 
- improving social functioning
9) Helps Relieve Asthma
Asthma is an inflammatory disorder that can be affected by the autoimmune system. Breathing, postures and relaxation yoga exercises can help asthma patients .
A Cochrane review involving 15 randomized controlled trials and 1048 participants found moderate-quality evidence supporting that yoga may improve quality of life and reduce symptoms in asthma patients. In some patients, yoga improved asthma symptoms and reduced medication usage. Practicing yoga, especially the variations that focus on breathing techniques, can ameliorate asthma symptoms .
10) Reduces Diabetes Symptoms
11) Helps with Depression
Yoga helps with depression by reducing HPA axis dysfunction and inflammation and by increasing BDNF.
A randomized controlled trial showed moderate short-term effects of yoga when compared to standard treatments for depression .
Yoga, alone or combined with antidepressants, helps decrease the Hamilton Depression Rating Scale even more so than antidepressants alone. The decrease in the Hamilton Depression Rating Scale correlates with the increase in serum BDNF levels .
In premenopausal women with back pain, yoga increases serum BDNF levels and prevents the drop in serotonin levels .
Yoga Nidra helps with depression and anxiety symptoms associated with menstrual disorders .
12) Helps with Post-Traumatic Stress Disorder (PTSD)
The normalizing effect of yoga on the stress response system may also help with PTSD.
Patients with PTSD showed reduced anxiety and stress when participating in a group yoga therapy program .
Women with PTSD, mainly from interpersonal violence involving intimate partners, exhibited reduced PTSD symptoms, depression, and anxiety after participating in Trauma-Sensitive Yoga .
Long-term yoga practice reduced chronic symptoms of PTSD in young adults. Yoga also decreased the chance of being diagnosed with PTSD .
Children suffering from trauma due to abuse or negligence in an urban setting found relief when participating in yoga-based psychotherapy over the course of 12-weeks. Their yoga focused on improving mental health alongside physiological health .
Yoga increased mindfulness and resilience and decreased PTSD symptoms in soldiers returning from or currently serving in the military .
13) Helps with Parkinson’s Disease Symptoms
Patients with Parkinson’s disease increased their physiological and psychological functions after participating in an 8-week yoga program .
14) Helps with Rehab from Stroke
After a stroke, patients who undergo 8-week yoga rehabilitation have improved brain and muscle functions .
15) May Help with Menopausal Symptoms
A meta-study showed that yoga might help with menopausal symptoms, including psychological, body-based (somatic), and vasomotor (i.e. hot flashes) symptoms. However, two randomized control trials included in this meta-analysis found no effect .
16) Improves Strength, Bone Density, Balance, and Flexibility
Performing yoga poses in the proper way strengthens your bones and muscles. It increases your flexibility and coordination and protects from injuries.
Hatha Yoga is physiologically beneficial to any age group, as long as it is performed properly to reduce any chances of injury. It improves core stability and balance, over the course of a 21-day program, from well-performed standing-stork and side-plank poses [55, 56].
Young women participating in yoga programs had increased upper limb strength and increased abdominal muscle endurance .
Women with increased bone deterioration improved bone mineral density and formation without medication from participation in group yoga focused on improving strength and stability .
In sedentary healthy and older adults, daily yoga practices improved functional fitness outcome over normal strength and conditioning exercises without the need for extra equipment .
In healthy adults, a 12-week Hatha Yoga program increased lung function, muscle strength and endurance, and overall flexibility without any serious muscle strain, and decreased resting heart rate .
Continued yoga practice improves muscle flexibility and connective tissues surrounding the bones and joints. Yoga helps build and maintain muscle strength .
Yoga also improves balance in male college athletes, which helps with sports performance .
17) Improves Sleep Quality
Older adults who practice yoga regularly reported better overall sleep quality, less disturbed sleep, less use of medications, and they also felt more rested compared to older adults who don’t practice yoga .
18) Helps with Fertility
Some causes of infertility in men include low sperm quality, anxiety, and obesity.
Yoga can improve sperm quality and motility. Practicing yoga can help improve prostate health. It can also reduce anxiety levels, which can improve sex life and help with mild erectile dysfunction .
Obesity can be a contributor to male infertility. Yoga practice can help regulate weight .
Mood can also affect fertility and sexual function. After three months of yoga, women reported improvements in stress, anxiety, energy, fatigue, and depression, which improve sex life and increase fertility. They also reported less back pain and headaches .
In combination with fertility treatments, yoga can help women by improving mental relaxation. By practicing yoga, women can lead a healthier lifestyle helping with fertility .
19) Beneficial for Cancer Patients
In cancer resource centers, non-pharmaceutical intervention for pain, stress, and anxiety are crucial to the wellbeing of the patients. Yoga is included in this intervention, which reduced stress and anxiety, improved mood, and increased patients’ perceived health .
Women undergoing treatment for breast cancer showed improved psychological functions after participating in a Bali yoga program. Depression in patients decreased, and the perceived quality of life increased over continuous yoga practice .
In patients undergoing chemotherapy for colorectal cancer, chronic side effects include fatigue, nausea, and muscle weakness. Individual yoga post-chemotherapy is an unconventional method that alleviated these side effects, boosting patients’ motivation to continue with chemotherapy .
Children suffering from fatigue due to chemotherapy and blood stem cell transplantation had increased mobility and strength after yoga including breathing exercises, warm-up exercises, yoga poses, and balancing poses .
Men suffering from prostate cancer undergoing 6 to 9-week radiotherapy had decreased fatigue, increased sexual health, decreased levels of urinary incontinence, and increased the quality of life .
Vivekananda Yoga has beneficial effects on both patients with lung cancer and their family members. The mental health and sleep quality of the patients increased, which in turn leads to decreased sleep disturbances for family members .
Potential Harm/Side Effects from Yoga
Practitioners can get injured during yoga, even when they are supervised by experts. Yoga teachers, who practice more intense stands, are more likely to suffer from adverse events .
In one survey of 110 Ashtanga Vinyasa practitioners, 62% of them reported at least one yoga-related injury, which was mainly muscle sprains and strains .
In traditional yoga, voluntary vomiting is a common cleansing technique. This technique can cause acid reflux symptoms or dental erosion. However, this practice is rare in North America or Europe .
Pranayama, which focuses mainly on breathing techniques, is not appropriate for beginners. Some extreme breathing techniques resemble hyperventilation, which can cause problems in people who do not know how to control their breathing .
Bikram yoga is practiced in a room heated to 105 °F with 40% humidity and is physically intense. The intensity and extreme heat during Bikram make it inappropriate for the elderly and people with medical conditions .
Finally, people with high blood pressure, glaucoma, lower back pain, and pregnant women should modify or avoid some yoga poses as they may cause injuries or aggravate some conditions . Fortunately, most yoga poses can be scaled down or made easier to suit the practitioner, so you should consult your physician or qualified healthcare practitioner to determine the extent to which you can practice yoga or if there are any poses to avoid.
The Yoga That I Do
Watch and perform this video, which I find very helpful to do at night.