Yoga balances the three defects of the Body (Tridosha principle)....

Yoga is a science that has been practiced for thousands of years and it's aim is to unite body, mind and soul. In yogic tradition flexible spine is the key to self and vitality. Just like a tree which bends down with the wind without breaking, 'life force' can move easily through a supple spine. Yoga helps one to sharpen the bodily awareness and concentrate in a meditative way.
Yoga is to balance the three defects (doshas) in our body. Those are Pitta dosha, Vata dosha and Kapha dosha which are known as 'Tridosha' principle in Ayurveda. Not only the human beings everything in the universe are categorised under according to the three doshas. The functional part of the body is governed by air, water and space/ether. They govern the psycho-biological and physio-pathological changes in our body. Vata-pitta-kapha are present in each and every cell in our body.
Pitta is the combination of water and fire elements.
Vata is the combination of air and space elements.
Kapha is the combination of water and earth elements.
Vata regulates movement, pitta controls metabolic processes and kapha functions through the fluids in our body. These three doshas are distinctly present in every living organisms and express differently in each according to the predominance of the elements.
Generally we are grouped in the three doshas based on the imbalance of the elements in our body and result in the corresponding doshas. The smooth functioning of the body is hampered due to the imbalances in the three doshas and results in the form of dis-ease. Negative emotions such as jealousy, anger, fear, insecurity, sadness, over confidence, stress and greed are created the imbalances of water, air, ether, fire and earth elements in our body. 
Breathing , asana, meditation and relaxation in 'Yoga' helps to improve muscle tone, flexibility, alignment, balance and concentration. Yoga helps to balance the glandular system, strengthens the nervous system and tap in the energy of mind, control the emotions and to be in your own self. Regular practice of yoga results in the balancing the five elements in our body for a better functioning of bodily systems, increased radiance, emotional balance, enhanced intuition and elimination of negative thoughts which are the essentials to keep away the ailments in connection with the three defects. Individual care is needed to avoid the foods which create discomfort related to our body type.