YeeeHaaah! Body size does not matter in kendo.
It does not matter how small you are, how skinny you are, how big you are, how tall you are, you can defeat others.
I was a tall kid but always defeated by a kid shorter than me.
I had a very staunch powerful guy as my opponent once but I could defeat him.
You do not have to be a macho. Besides, female can defeat male easily in the kendo world.
That is because the power or size is not everything in kendo.
Moreover, it does not matter how old you are. It is very common that old men in their 70s can seriously kick young people's butt.
Therefore, it proves kendo is not about speed either. If we want to be good at kendo, we must train not only physical side of our body but also mental side of our body.
Besides, we must train our personality as well. After all, we must learn self-control.
If you have a tendency to snap really quickly, you must learn how to calm yourself.
If you are too calm, you must learn how to be more energetic so that you will be able to overpower your opponent with your energy.
Anyway, the beauty of kendo is that size, gender and age do not matter. If you are on the right track, you will kick a lot of butt! (I do not mean literally!)