stimulate the lymphatic system and immune system." "This posture is great for runners as it provides a a deep hamstring stretch and helps ease any tightness in the ankle and hip joints," she says. "During this posture, you also strengthen the arms and spine

this area of the body, you're compressing and massaging the thyroid gland, which is responsible for regulating the metabolism and immune system. Instead of trying to take huge lungfulls of air, take little 'sips' of air and regulate your breathing

a PB-beating half-marathon, cortisol levels skyrocket, which leaves you vulnerable to nasty little free radicals which attack at cellular level and weaken your immune system. If you've ever had an impossible-to-shift cold virus after a period