Here is a link to a pretty good workout system. The idea is to follow a progressive system and BE CONSISTENT! This is an example of a functional system that is doable.
Practice cross-fit type training.
Learn a https://norsedefense.wordpress.com/wp-admin/post.php?post=3657&action=edit#copyapostmartial art or 2 or 3.
Practice cardio training while wearing your gear and without… (If you can’t breathe, you can’t move or fight…)
This is a lifestyle…
Here is a great exercise that is a good basic measure of “Combative Fitness”: