Confused about Gain, training and nutrition

HI there. So i've passed the two year RNY mark, and i'm training for a half-marathon in a few weeks, and a full in the fall.

I was told to up my calories from about 1,200 to about 1,400 on long run days. And now i'm seeing a 5 pound hike in the scale...which i'm not happy with. I know that our bodies catch up after two years, and some people see a bit of a gain, but i'm just not ready for it.

Any advice?

Sometimes when you have a spike in training, you can be having muscle gain that outpaces fat loss. I hit my lowest when I was training for my first Half but since it wasn't an intense program, I didn't have much change in muscle definition. When I was training for my second Half, it was a very good program with alot of speedwork - - I too saw the scale going up but also saw increased muscle strength & definition with no change in clothing size. In effect, my weight distributed to heavier muscle (about 5 lbs from lowest) but it took my finishing time down by 15 min for my 2nd half!! Now I'm training for a full too, and I just have in my head that training doesn't mean I go carb-crazy..... 

Advice would be to pay attention to your measurements - if they're changing in abdominal fat, then it's probably not the good gain but if you're seeing an increase in muscle mass in your legs, that's a good gain b/c it'll make you a better runner!!