Hi @Roglow , I only started running seriously at the age of 47...age is no barrier to running fast, don't worry! In order to build speed you need to do short bursts of fast running. There are different ways of doing this, the best known are interval, tempo and Fartlek training - running at high speeds, followed by recuperation. This article explains the difference between the 3 techniques.
http://www.runnersworld.com/race-traini ... erval-runs
Good luck!
http://www.runnersworld.com/race-traini ... erval-runs
Good luck!