In Likkutei Torah, a hasidic work by Rabbi Shneur Zalman of Liadi, “with all your might” is interpreted as follows:
In everything that one does, one must do more, in the sense of “meod,” which literally means “more” (Shir HaShirim 16:3).
This understanding of “meod” makes “with all your might” an even higher level than giving up one’s life; giving up one’s life requires a moment’s decision, and with that the matter is settled, whereas “with all your might,” as the Likkutei Torah understands it, represents unending love of God.
–Rabbi Adin Steinsaltz
From Talks on the Parasha