In fact, this question mainly depends on yourself. If you can exercise regularly and systematically, you should be able to change your circumference in all aspects in about three months, but the strong circle you mentioned makes people feel obvious physical changes, and it is estimated that you need at least half a year of hard training. Generally speaking, it takes a long time for people who have never been exposed to fitness to adapt and get used to it, so it is basically difficult to reach what you call a strong circle within three months, and half a year is possible.