Yoga: what the evidence shows for health, how to reduce injury risk and how to choose a teacher

The US National Center for Complementary and Integrative Health describes yoga as an ancient Indian practice, now popular for physical and mental wellbeing. In the US, practice typically emphasises three components: physical postures, breathing techniques and meditation.

Styles differ, and NCCIH specifically mentions hot yoga as one variety, so a statement that yoga is good or bad for a condition means little without knowing which style and how it is taught. Cancer Research UK describes sessions as lasting between 60 and 90 minutes.

NCCIH sorts the evidence into tiers. Strong evidence is described for stress management and general wellness, neck pain and tension headaches, low-back pain, and weight management in overweight and obese groups. Moderate evidence covers anxiety, depression, sleep quality, balance in older adults, migraine and menopause symptoms.

Evidence is described as promising but limited for knee osteoarthritis, smoking cessation, substance use disorders, cancer symptom management, post-traumatic stress and chronic disease management. A 2022 review found yoga slightly better than no exercise for low-back pain, although the difference may not be important to patients. Most studies involved predominantly female, non-Hispanic White, well-educated participants, so results may not apply equally to everyone.

NCCIH says yoga is generally considered a safe form of physical activity for healthy people when performed properly under the guidance of a qualified instructor. The most common injuries are sprains and strains, mostly of the knees and lower legs, and serious injuries are rare. Adults aged 65 and over have higher rates of emergency department treatment.

Learning without supervision has been associated with greater injury risk. Beginners are advised to avoid extreme practices such as headstands and the lotus position, and to be aware of the dehydration risks of hot yoga.

• Ask the teacher about their training and experience.

• Tell them about injuries, pregnancy and medical conditions before class.

• Back off from any pose that causes sharp pain, and do not push into the lotus position early on.

NCCIH states that physical activity including yoga is safe and desirable for most pregnant women with appropriate precautions, and recommends avoiding hot yoga and poses involving prolonged stillness or lying on the back. A 2022 analysis found that pregnancy yoga reduced anxiety, depression and labour duration while increasing the likelihood of a normal vaginal birth.

For people with cancer, Cancer Research UK says evidence is limited. A 2017 Cochrane review of 24 breast cancer studies found yoga can sometimes help with sleep, tiredness, anxiety and depression, though results need cautious interpretation, and there is no evidence that yoga can cure or prevent cancer. It advises waiting two hours after eating and telling your teacher about medical conditions.

Cancer Research UK notes that the UK lacks unified regulation of yoga teachers. Teachers commonly belong to organisations such as the British Wheel of Yoga or Yoga Alliance Professionals, but membership is voluntary and requirements differ.

Yoga therapy is a more specific route: the Complementary and Natural Healthcare Council lists yoga therapy among the 18 professions on its register, which is approved as an Accredited Register by the Professional Standards Authority. A general yoga class teacher and a registered yoga therapist work at different levels of clinical focus, so ask which you are seeing and what their training covers.