If you’re doing exercises to tone weak muscles, then such exercises are very complementary to Dragon & Tiger or other qigong practices that we teach. Chi doesn’t move well through weak or flaccid muscles, so toning muscles is a good idea. Think of a baby or young child. They are very strong, yet their muscles are very toned and relaxed.
If you’re doing exercises designed to build muscles in such a way that they stay in constant contraction (i.e. hold strength), then these are not that complementary. Chi does not move well through muscles that hold contraction, tension, or strength. Such exercises will block the flow of chi in our body and perhaps diminish the effectiveness of Dragon & Tiger.
However, practice of Dragon & Tiger can help you do those exercises better, if that was your primary interest. If you learn to let contracted muscles relax better between exertion or holding, then they function better. That at least is the theory, and I have had students who were weight-lifters who were looking for ways to lift more weight, and they said the qigong they did helped.