One of the many ways that walking promotes health is that every time you take a step, you are activating the acupuncture point just below the ball of the foot called Yongquan (Bubbling Spring).
Yongquan may be activated while walking by allowing your heel to tap the ground gently, and then allowing your weight to transfer fully to the ball and toes of your foot. Focus on breathing into your lower abdomen. Keep your shoulders relaxed and allow your arms to swing freely. You may also perform acupressure on the point by rolling a tennis ball or tapping a loose fist on the ball of your foot.