I got this link from Chabad... This is a video of the Lubavitch Rebbes 1982 Pre-Passover Farbrengen...
I have watched the first half so-far and I think it is very motivational. He says that man should not 'retire', that he should use every moment of life to grow, both physically and spiritually. The Rebbe was a very good speaker. He speaks in Hebrew with English sub-titles...
http://www.chabad.org/multimedia/movie_cdo/aid/1480910/jewish/Pre-Passover-Farbrengen.htm