Right now I am slowly (oh so slowly) putting on base miles on the bike. I have a 30 mile road race I am planning on doing the end of May, and then maybe a few of the state time trials and hopefully most of the Mt. bike season (it's only 6 races here in Maine). Then I'll try some 'cross races in the fall. I want to work myself up to and maintain 7 hours of exercise a week. I need to run to lose weight, and for CX and Mt. Biking. But out of that 7 hours how much should I commit to running?