I am a tri/duathlon wannabe. I am a beginner runner and slowly working my way up to running 5km. I figure I'll be there in another week. So... assuming I can do 5km in 30 minutes and can easily ride 32 km, how manageable would it be for me to do a 5km run, a 32km ride, and a 5 km run? Is doing 2 5 k runs on the same day (separated by a ride) waaaaaay harder than doing one run?

How long would I need to train for this if my goal was to finish within my own reasonable time? (Let's say my goal was 2-30 min runs and 70 min for the ride (conservative guess - it's mostly flat or rolling with one 350' climb over about 2 miles.) So - 2 hours, 10 minutes?

There's a duathlon on Mother's Day this year...