[Jadaku]

Hello,

I am interested in learning how to combine two phrases in Kanji characters.

The first phrase is Kiryoku (inner strength).

The second phrase is Nin tai (perseverance).

I would like it to symbolize "train inner strength to persevere." By "inner strength" I am referring to self-discipline and self-control. So please correct me if I'm not using the right terminology. I am interested in writing the phrase vertically. I am limited on space so I would like to use as few characters as possible.

Any help, thoughts or comments is appreciated.