Taixi, or Kidney 3, is the source point of the kidney meridian and an excellent point to massage whenever feeling fatigued.
To locate Taixi, first locate the medial malleolus (the bone of the inner ankle). Then, locate the Achilles tendon that runs down the back of the ankle. Directly between them you will find the tender area when you press.
Massage the area on your ankle between the bone of inner malleolus and the Achilles tendon.