What should I expect during training?

It typically takes 1 week (3 trainings) to learn the best techniques. Weeks 2 and 3 are termed neural adaptation - that is you acquire the muscle skills to coordinate all the muscles for optimum breathing. From 4 weeks on you get structural/morphological change in your muscle itself with plasticity so that fibers actually change roles. For example you may get a higher proportion of endurance fibers while your power fibers get bigger.