It's normal to want to compare yourself to others, but there will always be somebody out there faster, stronger, and with a better physique. Instead, focus your efforts on being the best you you can be.
"The faith of Christ offers no buttons to push for quick service. The new order must wait the Lord's own time, and THAT IS TOO MUCH FOR THE MAN IN A HURRY. He just gives up and becomes interested in something else." ~ A.W. Tozer