Strenght training: Maintaining strenght in building period

Having recently passed Easter I've entered my building period when it comes to periodization. One of the consequenses from that is that I have to move my attention from general strenght training to sport spesific training. Running hills, intervalls and steady state runs will build on what I've gained in the Basic-period from January to March. Anyhow, I have to maintan my basic level, and in order to do so I schedule one session a week. I use the same program but with two sets instead of four-in addition to the warm-up set. If I feel that any of the exercises connected with my legs generate stiffness in them, I eliminate the exercise. One week area for me is the abdomen-area. That one I have to schedule unchanged through the year, except tap- and raceperiods. In tap-and raceperiods I don't do any strenght training at all. This spring that basically means in June.