The race the apostle used the athletics of he world to symbolise is the race from the world to heaven (the journey from earth to heaven) (Heb. 12:1).
It can be contrasted with the race that the Lord Jesus undertook – the race of going from heaven to the cross. The latter is going from glory to grief, while the former is going from grief to glory (so to say).
The apostle symbolised this heavenly race with the athletics of this world because of the fact of it having features like those found in the athletics of the world. These features are the rules involved (cp. 1Cor. 9:25; Matt. 28:20).
So then, it follows that if anyone claims to be in the heavenly race, but does not bother about the rules, the one is deceiving oneself.