It is ok to exercise in 40 minutes. After 40 minutes, fat begins to turn into muscle, and once it becomes muscle, it is more difficult to lose weight.
If you are a girl, go to yoga. Yoga can shape and cultivate temperament.
After a long time, you will naturally lose weight, but yoga is a long process. You should be ready, don't worry.
If you are a man, of course you still have muscles, hahahaha!