Yoga Explained Simply

1. What It Is About

It originates from ancient Indian philosophy. In research, it is mostly about Hatha Yoga. This includes body postures called Asanas, breathing techniques known as Pranayama, and meditation. Depending on the style, the practice looks different, for example in Iyengar or Vinyasa. Studies also do not always practise the same thing. Some investigations test only a single breathing exercise, such as Sheetali Pranayama or Bhramari Pranayama. Others test an entire programme of postures, breathing and relaxation. Therefore, yoga is not a uniform treatment, but a variety of techniques with different emphases. The tradition assumes that body posture, breathing and attention interact. In research, this is therefore referred to as a multimodal approach, that is, an approach with several components at the same time. Often, studies lack precise information on how long and how intensively the practice was carried out and who guided the exercises.

2. What the Studies Show

The best investigated are fatigue, that is tiredness and weakness, and mental performances such as attention and memory. There are also useful studies on pain, anxiety and sleep.

A controlled study examined people with chronic back pain. A comprehensive yoga programme improved pain, anxiety and depression more than a pure exercise programme 1. This is noteworthy because the comparison group also exercised.

Several studies tested individual breathing exercises. In people who were in home isolation due to COVID-19, Bhramari breathing improved stress, anxiety, depression and sleep quality 2. Women who were irradiated for breast cancer reported less fatigue and better sleep 4. In people on dialysis, that is blood purification, fatigue decreased 6. In people with multiple sclerosis, Bhramari breathing improved fatigue and depression 8. Children with asthma showed better asthma control and quality of life 9.

A meta-analysis, that is a summary of several controlled studies, found indications of a benefit of breathing exercises for mental disorders 7. Such summaries are considered the strongest evidence. Further studies concern anxiety and depression in cervical cancer 3 as well as pain, fatigue, sleep problems and self-confidence after bowel cancer surgery 10. A study with adolescents over six months examined the response to stress 5.

In these studies, it was observed that values improved. Whether this results in a lasting benefit is not stated.

3. What Remains Unclear

Much is open. It is unclear whether yoga changes the course of a disease or the quality of life in the long term. The question of how often, how long and how intensively one must practise is also not clarified. The mechanisms of action are only partially understood. One problem is the lack of uniformity: studies test different breathing techniques with different durations, direct comparisons are hardly possible. Often programmes are referred to as yoga that mix breathing, meditation and movement, so it cannot be said which part has an effect. Some results, for example on blood pressure or glaucoma, are based on smaller studies and have not been repeated. Many studies were also conducted on specific groups, for example on nursing staff or on cancer patients. Whether the results apply to other people remains to be seen.

4. What This Means in Everyday Life

Yoga is one of the most frequently studied complementary procedures. Those interested in it will therefore find a comparatively broad body of research. However, the findings are not equally strong. The most robust results are on fatigue, anxiety, sleep and pain, and there especially in people with an existing illness. For healthy people and for prevention, the situation is less clear. Because yoga is not a uniform procedure, a study result always says something only about the programme that was practised there. Those reading reports can pay attention to which exercises were tested, over what period and in whom. The next question to be clarified is whether the observed improvements persist over months and years.

All Details with Study Numbers and Sources: Detailed Page on Yoga. For Children: Yoga for Children.