A class will usually be labelled as Hatha yoga when it doesnât fit the description of one of the more specialised and stylised classes such as Iyengar, Bikram, Ashtanga, Vinyasa, or Power Yoga. The class structure and intensity is set by each individual teacher, following a loose structure of a gentle warm-up, moving through physical postures, and finally a meditation or relaxation session in these cases.