Everyone who competes in the games goes into strict training. They do it to get a crown that will not last, but we do it to get a crown that will last forever.
NIV
Now every athlete who goes into training conducts himself temperately and restricts himself in all things. They do it to win a wreath that will soon wither, but we [do it to receive a crown of eternal blessedness] that cannot wither.
AMP
And every man that striveth for the mastery is temperate in all things. Now they do it to obtain a corruptible crown; but we an incorruptible.
KJV