Taking into account that LCH searches for New Physics are failing, the electroweak effective theory seems to be appropriate to deal with current energies. Tracks of new higher scales can be studied through next-to-leading corrections of the electroweak effective theory. Assuming strongly-coupled scenarios we have considered high-energy Lagrangians which incorporate explicitly new heavy fields. Then, and integrating out these heavy resonances, we study the pattern of low-energy constants among the light fields which are generated by the massive states. A generic non-linear realization of the electroweak symmetry breaking with a singlet Higgs is assumed. The importance of the high-energy behaviour of the underlying theory and different possible descriptions of massive spin-1 resonances are analysed.