If it is to increase muscles, anaerobic exercise is the main method, supplemented by aerobic exercise; If you want to lose weight, the other way around.

In addition: when you see the purpose of going to fitness, you know that you have made a mistake: the best way to increase muscle is not to exercise regularly, but to grow during rest. Go to the gym three or four days a week and exercise every other day. It is best to exercise different muscle groups every time. Muscle doesn't grow under a lot of exercise, but the torn muscle fibers become thicker after a lot of exercise. The muscles did not increase, but the muscle fibers became thicker and seemed to increase. The key is plenty of exercise+rest+plenty of exercise+rest, supplemented by adequate intake of protein.