I'm a 25yr old, 6'2" @240lbs, and I've just started Starting Strength. I work in IT, and my level of strength, fitness and body fat screams "works with computers". To top this off I was a heavy smoker (all but quit now) and consumed a heroic amount of recreational drugs and alcohol during the last 6 years.
After 3 weeks, I have made good progress and the novice program fits nicely with me. The weight lifting part is coming along very smoothly (although I'm only squating 65kg and deadlifting 80kg, which I realize is terrible at best). But I need to add cardio to this as I simply do not have a job or hobbies which are in any way physically demanding. I've started to walk about 2 miles instead of getting a bus home after work, which is good. But I want to get back to running again. I know this will impact my strength gains, its a price I'm whiling to pay atm.
My question is, would running 2000m on a treadmill 3x's a week after my work out be enough? (It takes me around 18mins) Or would I be better off doing it 2x's a week on my rest days? Or would it be better still to do 40-60mins 1 day a week? My preferred cardio is running on treadmills. I've ready a few posts here that suggest this is worthless, but given my physical state would 20mins of running after my weights session not be beneficial, at least initially? I do plan on moving on to kettlebells in 3-4 months but currently they would kill me.