The exam difficulties vary a bit, with each certifying organization having its own ways of testing individuals. But, in general, the group fitness certifications are not too challenging when compared to personal training certifications. This is largely because group fitness instructors do not need as advanced of a knowledge of more complicated topics like biomechanics or bioenergetics. It isn’t as relevant to the practice of group fitness instruction as it is to solo instruction because group fitness instructors need to focus broadly on many clients at once instead of deeply focusing on just one client at a time.