Running: Day 1

I've been debating on picking up running. I went for my first run today at the gym. I did:

1/4 mile walk
1 mile run
3/4 mile walk
1/2 mile run
1 1/2 mile walk at a steep incline

So 4 miles, 1 1/2 of which was a run. Not bad for day 1 right? I'm thinking I might try to run 3 days a week and see how it goes. I tried running once before but I started having trouble with one of my knees. But for now, I feel fantastic. The only downside...... running is REALLY boring. So like I said, we'll see how it goes.