Asanas gives your body physical flexibility,stretching and strength to combat ageing. Intake of oxygen-the yogic way,increased blood circulation in all the body parts replenishes the cells which are being degenerated resulting in overall better performance of the particular organ,which actually means alleviating ageing. The inverted poses like headstand and shoulderstand bring blood circulation to brain and face thus increasing the glow and alleviating pimples ,acne and dark circles from the face.
Pranayama or prolonged and conscious breathing help us control our senses and thus is the biggest stress buster-a silent killer in the modern times. Stress leads to high BP and heart attacks and anxiety or depression. Studies have shown that regular practice of various techniques of pranayama reduces stress and thus stops ageing process.
The sattvic diet recommended in yoga plays an important role in keeping the weight down,the bowels movement and the flow of prana in all the cells of the body.
Apart from this all the limbs of yoga including yam, niyam, meditation helps in combating ageing.