You practise : the running on road, the running trail ), athletics or practise the cross-country, also you practise the active walking or nordic walking, it's always interesting and sometimes even indispensable to get closer to unions. They put you in connection with clubs, the other followers and inform you of sports events in their domain. Here are some links of the main sporting unions of running.
Internet : http://www.uka.org.uk
Internet : http://www.britishtriathlon.org
Internet : http://www.athle.com
Fédération Française de Triathlon - Duathlon
Internet : http://www.fftri.com