Updated: Jun 10, 2021
In my book, The Short Fight, I write about the importance of training to defend yourself against a bigger, or stronger person. In all species, there are predators and preys.
While many larger animals are left alone because of their sheer immensity (think elephants etc.), the smaller or weaker looking animals are always "tried" first. This is because the predator would prefer an easy meal as opposed to having a fight for their lives.
So, it's important to develop your body so you can effectively defend yourself. Additionally, having a strong looking body is a visual cue to a would be attackers that you can pose a problem for them if they attack you.