For fitness
As far as there is no foundation (general veterans basically don't need to practice physical fitness), physical fitness is the main thing, and strong cardiopulmonary function is the guarantee of health and the basis of strength training.
Otherwise, if the gap between groups is short and the heart and lungs can't breathe evenly, the next group will be unable to resist.
Famous bodybuilders generally engage in physical training in their early years and have a good foundation. For example, China strongman Gu Yanli practiced middle and long distance running in his early years, and Ronnie Coleman played football at school.
So I think physical fitness comes first.