If you really know the movements for the big compound freeweight exercises, you can probably put together a full body workout that you can compress into a single session. At 2X per week you'll have enough recovery to support this.<br><br>
If you don't know those compound exercises well, and have access to a gym, a really good tradeoff is to use machines for about 2/3 of each workout and then spend the rest on one or two compound exercises training the movement. I'd guess that it takes about 8 weeks to really get a movement down - a few weeks at very light weight, then gradually increasing. This actually grows nerve connections and the skill to put all the muscles together.<br><br>
Compound exercises include bench or incline bench, deadlifts (I like Romanian deadlifts) squats, pullups, military presses, etc. They are really time efficient because they work so many muscles at once. Dumbbells are the least stable, and so require the most different muscles to support them.<br><br>
I personally spend almost as much time as you mention on "prehab" exercises which are the opposite of the big compound ones. I have a list of little running injuries or twinges I've gotten that require specific work on a few muscles to avoid running injuries. Sadly, as you get older you have to spend more time on this stuff - I always do it first and the rest when I have the time.<br><br>
I do leg work after running, and never before a big thing the next day. Having some muscles more tired than others before running has led to sloppy running and injuries for me.
