2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/199888We show how to constrain the physical spectrum of walking technicolor models via precision measurements and modified Weinberg sum rules. We also study models possessing a custodial symmetry for the S parameter at the effective Lagrangian level - custodial technicolor - and argue that these models cannot emerge from walking type dynamics. We suggest that it is possible to have a very light spin-one axial vector boson. However, in the walking dynamics the associated vector boson is heavy while it is degenerate with the axial in custodial technicolor.Two columns, RevTex, 4 pages, 5 eps filesHigh Energy Physics - Phenomenologytext