Ever thought if you could run like the characters of your favorite dc and marvel comics like flash, quick silver etc. how much fun it would be to go with the speed of light. So is it really possible to travel with such a high-speed? The answer would be no, as you would require an infinite amount of energy to move because as you approach the speed of light your mass becomes infinite. Stated in the energy mass equation given by Einstein.
E = mc2
But, let us suppose somehow you contradict this theory and you got energy to accelerate yourself to the speed of light what would happen
Time dilation
if you could achieve a speed of 90% of the speed of light, you would experience a phenomenon called as time dilation, meaning that passage of time for you would be halved i.e. your clock will advance about 10 minutes (not only our clock but over body will also notice a change of only 10 minutes), while 20 minutes would have passed for the observer.
You would be burnt to ashes
As you are running at such a high speed your body will heat up due to the friction with the air particles and as a consequence would burn up to ashes. other than that running at the speed of light, a pebble hitting your body would feel like a bullet.
miscellaneous fact
By running at the speed of light you can circle the earth at the equator at 7 times per second
