This would be great for me too as I want to simulate a user stopping at a location for a set period of time :)
Thanks for suggesting this Simon. There isn't any way to do this currently. I've added it to our Feature Requests list (number 73) where anyone interested in it can vote for it.
I would like to be able to add in breaks to a hike to allow those following the route using times to have accurate times including the breaks.
For example, you stop for a break of 10 mins on route the timings currently do not take this in to consideration. I would like to make it so if you stop at 1500 the timings continue from that point from 1510
Is there a way to do this?