That is almost certainly a short term result of an increase in intensity of running and weight training. After exercise your body will prep the muscles for near future use by loading them up with energy in the form of glycogen. Running especially adds to that short term weight gain because your leg muscles are larger compared to upper body. The good news, that increase is not a trend, not an increase in fat, and not a problem unless you have a short term weight threshold, like cutting to make weight in wrestling.