2015 Goal : " Be my own Hero"
" Choose Joy"
Courage ! Do one brave thing today...then run like hell.
RunCheffyRun, I think that if the plan gives you a option to cross train that it is intended to be a recovery day, so you don't want to do a tempo run on that day. My suggestion would be to build up to 22-24 miles a week before thinking about tempo runs. In the meantime do a few fartleks, run tempo pace for 30-45 seconds 3 or 4 times during a run once a week. It's too soon to be concerned about speed.
Trust the plan or find another because too much too soon will probably get you injuried.
"You NEED to do this" - Shara
Prince of Fatness