Yoga

Yoga is a system of physical postures, breathing and relaxation that originated in India. As practised in gyms and studios in Britain it is mainly a form of exercise that builds strength, flexibility and balance. The NHS counts it as a muscle-strengthening activity.

Benefits

Regular practice improves flexibility, balance and muscular strength. Studies suggest that it can help with low back pain, and many people find that it reduces stress and improves sleep; see yoga and mental health. Most styles are not vigorous enough to count towards the weekly target for aerobic activity.

Styles

• Hatha: a general term for classes of slow, held postures, suitable for beginners.
• Iyengar: precise alignment, with blocks, straps and chairs used as supports.
• Vinyasa or flow: postures linked in a continuous sequence, more energetic.
• Ashtanga: a fixed, demanding series performed at a brisk pace.
• Yin and restorative: long, passive holds, aimed at relaxation.
• Hot yoga: practised in a heated room.
• Chair yoga: adapted for people who cannot get down to the floor.

Hot yoga

Hot yoga classes take place in rooms heated to between about 30 and 40 degrees Celsius, often with added humidity. The heat makes muscles feel looser and produces heavy sweating. The weight lost in a class is water and returns on drinking, and there is no good evidence that sweating removes toxins.

• The feeling of looseness makes it easy to stretch too far and strain a muscle or joint.
• Dehydration, dizziness and nausea are common in newcomers. Water is drunk before, during and after the class.
• Anyone who feels faint, sick or confused leaves the room and cools down.
• Hot yoga is not advised in pregnancy, and people with heart disease, high or low blood pressure, diabetes or a history of fainting take medical advice first.

Starting

• A beginners' class with a qualified teacher is the safest introduction. Yoga teaching is not regulated in the United Kingdom, so it is reasonable to ask about a teacher's training and insurance.
• The teacher is told beforehand about injuries, health conditions and pregnancy.
• Comfortable clothing and a non-slip mat are all that is needed.
• Postures are entered slowly. Mild stretch is expected; pain is a signal to ease off.
• The NHS publishes free yoga videos for practice at home.

Cautions

Most injuries in yoga are strains of the back, neck, shoulders and knees, usually from forcing a posture. Headstands and shoulder stands put load on the neck and are best learned under supervision or left out. People with glaucoma, osteoporosis or uncontrolled blood pressure are advised to avoid some positions, and specialist classes exist for pregnancy.

Other ways of maintaining flexibility are described under stretching and flexibility.