mikhou wrote:A little late to the party here, but initially just let me say that, yes, running 3 days/week can be enough. I trained for my last half-marathon on 3 days/wk running and 2 days/wk of strength training, and I set a PR in the half. I was using this type of training plan:
http://www.runnersworld.com/race-traini ... ining-plan. And I didn't even follow it to the letter because you're supposed to do aerobic cross-training workouts 2x during the week aside from running (cycling, swimming, etc.). I didn't do that. I strength-trained 2x/wk and I occasionally played racquetball. Other than that, I just ran. The point is that, yes, 3 days/wk can be enough.
That being said, most half and even full marathon plans for beginners have you running 4 (maybe 5) days/wk. So the way that I see it, you could go one of two ways. 1) If you have seen improvement on 3 days/wk running, keep doing it. Your improvement may not be as fast as you want, but if you are seeing improvement, don't fix what isn't broken. 2) The other option is to add some distance weekly but slowly. I would not go from 3 days/wk straight to 6 days/wk. In fact, in your situation, I wouldn't exceed 4 days/wk for a long time while your body adjusts to the volume. I find that a lot of distance work beats me up more than heavy lifting, and this is coming from a guy who used to do a lot of distance work (running 4-5 days/week before that last half-marathon). So if you feel the need to increase, do so slowly, but if what you're doing now is giving you results, stick with it until you aren't getting results anymore and then change.