If I flex my bicep and continue to contract it does it mean that the muscle cells are in depolarizing state and not repolarizing?
No, macroscopically human muscle works by oscillation. This means that when a muscle is contracted (isometric contraction), some fibers alternatively contract through the actin/myosin process while some others relax at the same time. The end result is that the muscle as a whole keeps the same length, although it still does consume energy to stay in that state. That is why you get tired after some time of isometric contraction. To directly answer your question, it means that muscle in isometric contraction state will have some fibers depolarized, and others in resting state at any moment.