So the following exercises should be part of your program to provide a complete approach to stability and torso stiffness.
Carry ExercisesWith all of these exercises the key points is keeping the torso rigidly upright. This focus on torso stiffness is essential to training the torso for both daily life and martial applications.
This exercise develops unilateral stability for the back by placing the weight on just one side. The muscles used are similar to those used in basic side plank, but we are able to combine that stimulus with the complexity of moving and using the shoulder to control the weight.
This exercise puts weight in both hands and can be done with quite significant amounts of weight. The focus here is on structural loading - the torso development inherent to holding a large weight off of the ground.
Both the Farmer's carry and Suitcase carry can also be used for training grip strength for grapplers.
Here the weight is held upright thereby focusing the effect on upper body stability. Lower weights are used and the limiting factor is usually the forearm muscle's ability to keep the weight in place. This exercise is usually shown with a kettlebell, but as you can see here, plates with handles work just fine.
To achieve fine tuning with weight, and to make it more sword specific, an adjustable dumbbell can be used with weight on just one end and held upright.
ProgrammingThese exercises make good finishing exercises done at the end of the workout. Attach each of these to one day's workout and do all three over the course of a week. Each set should be about 12-16 paces. You can work your way up in duration as well as weight, while maintaining good form.
For most fit individuals the Suitcase carry starting around 25-30 pounds is usually good. The Farmer's carry can usually start with a dumbbells of the same size in each hand. Start small with the weight to practice good form at first. For folks most starting with 8-12 pounds for the Bottom's-up should be reasonable. Be sure you can keep the weight safe with this exercise since getting hit in the forearm by a heavy bell will ruin your training.
The exercises illustrated here help to turn on the stabilizing muscles of your hip. They will increase your knee stability and hip power. The mini-bands can be bought from Perform Better. They come in several strengths.
Start easy and work your way up slowly. We are mostly interested in the endurance of these small muscles and making sure they are active. They will never be big strong muscles.
For the walks, after you get used to the band around your knees move it down to your ankles. Later you can move the band to your around your mid-foot, this emphasizes the hip external rotation component of the exercise.