A non-linear sigma model effective lagrangian is analyzed for theories in which supersymmetry is softly broken at scales below the electroweak symmetry breaking scale. Besides the gauge and matter supermultiplets, the low energy theory contains only three Goldstone chiral multiplets. The higgsino, gaugino as well as the charged and neutral Higgs bosons have (light) phenomenologically acceptable masses, the values of which depend on the explicit soft supersymmetry breaking parameters. In addition, the longitudinal vector bosons become strongly interacting at high energies ( M z ⪡ E ⪡ 4 πν). The equivalence theorem is exploited in order to obtain their scattering amplitudes. Furthermore, supersymmetry results in enhanced longitudinal vector boson production of Higgs bosons.