Through siddhi development, which is the mastery of metaphysical and spiritual powers, one can decrease the weight of the body to near weightlessness.

In that way and through the laws of the universe which state that energy is conserved, merely altered and never destroyed, by decreasing ones mass to near zero (remember that in higher realizations the body becomes light, with little to no mass if chosen), one can keep energy constant and reach speeds of light.

While this is not a party trick, teleporting or moving the light body to the speed of light yogis, monks, and those who have mastered the art of teleporting can and do travel at speeds of light.