Originally Posted by
TheOtherZach
Edit: I turn 30 this summer. As far as general fitness, I can jog 3 miles in under 30 minutes for what that is worth. I started riding again about a month before my first commute attempt. Nothing too long, just a bunch of 6-10 mile trips without any difficulty.
Jogging isn't cycling. Different muscle groups.
I'm willing to vote that it's a conditioning thing at this point. Is every other day a workable option and then ramp up from there?
And a MTB isn't the best option honestly. That's from someone (me) that daily commutes almost the distance you're trying and on Fisher MTB's to boot. You'll get there, but it's not the most efficient of modes. It's a lot more spinning at a lower speed than a more road oriented bike. And fit can and is key to surviving it.