Originally Posted by
MDcatV
You should be able to, but your cycling will definitely suffer. It has to. If you are committed to running the marathon, then I would recommend scale back the intensity on the bike and use cycling only as recovery/low intensity aerobic, otherwise your potential for injury/illness will go sky high.
Running, I'd recommend, dont do too much too soon. With aerobic fitness in the bank from cycling, your lungs will feel like you should be able to run more than your legs can handle, and you're going to be stupid sore - especially going down steps - for a few weeks.
Bonus, running sucks so much that you'll really be motivated to get back on the bike and tear it up come racing season.
Heh - I'm realizing that this morning. Yesterday my second mile was nearly sub 7 minutes. I've only been in serious run training for a week. I was so freaking sore last night and this morning.
I actually got into cycling via running. Last time I trained for a marathon a few years back I got achilles tendinitis really bad. I switched to the bike after that.
I don't care about having the fastest marathon time in the world, I just want to complete one. It would be cool to do it around or under the 4 hour mark.