Between routes I've created on the Viewranger website then synced to my Android phone and the tracks recorded when I walk the routes, there's a consistent 40-65% discrepancy. The routes created on OS maps give a reading for ascent in feet, e.g. Land's End to Penzance as 2772 ft (= 852 metres) which, when walked, turn out to be 40-65% greater - 1184 metres in this example. This matters because I'm planning to do LEJOG next year, starting with the northern side of the SWCP, and do not want to underestimate the ascents in north Devon, thereby potentially scuppering the whole enterprise.
Do others experience the same thing? Is it simply down to adding more waypoints when creating the route?