  Starting from a theoretical representation of the electroweak component of
four-fermion neutral current processes that uses as theoretical input the
experimental measurements at the Z peak, we consider the asymptotic high energy
behaviour in the Standard Model at one loop of those gauge-invariant
combinations of self-energies, vertices and boxes that contribute all the
different observables. We find that the logarithmic contribution due to the
renormalization group running of the various couplings is numerically
overwhelmed by single and double logarithmic terms of purely electroweak
(Sudakov-type) origin, whose separate relative effects grow with energy,
reaching the 10% size at about one TeV. We then propose a simple "effective"
parametrization that aims at describing the various observables in the TeV
region, and discuss its validity both beyond and below 1 TeV, in particular in
the expected energy range of future linear electron-positron (LC) and muon-muon
colliders.
