In this talk, I will present our studies aimed at understanding the life-cycle of radio-loud AGN and the role of cold gas in it. These studies make use of (or prepare for) the exciting possibilities offered by the new generation of radio telescopes. The evolutionary stage of radio AGN (young, adult, dying, restarted) can be derived from the radio spectra and morphology, in particular by using the capabilities of new low-frequencies radio telescopes. Our study of their duty-cycle has been done in the MHz-domain using the LOFAR radio telescope and the continuum surveys now in progress. I will summarise the results and compare them with evolutionary models of radio sources developed by our group. In the second part of the talk, I will present the results of our study of the effects of the radio plasma on the surrounding medium. Surprisingly, and despite the extremely energetic phenomena involved, these effects can be traced by the cold component of the gas using the atomic HI-21cm and the molecular (CO) components. I will discuss the presence of these fast and massive outflows and illustrate their physical properties using results from ALMA observations. I will compare them with numerical models describing the effects of radio jets, that appear particularly strong in the first phase of life of the radio source. Our results on the HI outflows are preparing for large surveys that are about to start with SKA pathfinders.