Weight training exercises can help develop casting muscles. These muscles can be developed through a program of resistance training. Gripping a long handled ax or sledge hammer like a rod and lifting it in sets of repetitions can develop these casting muscles.
Perform 3 to 6 sets of 12 reps every other day for about 6 weeks. As strength develops use more resistance by increasing distance between ax head and wrist.
Good casters have powerful power strokes and well-conditioned muscles. It requires wrist strength to keep the wrist motionless.
In addition, dumbbell training may help condition forearm casting muscles. Exercise the muscles used in the casting strokes motion by lying prone on a weight bench, and then while leaning over the bench lift the dumbbell in the backcast stroke. Forward cast muscles are developed by placing your back on the bench and reversing the exercise. Again, 3 to 6 sets of 12 reps are performed 3 times a week for at least 6 weeks. Increase resistance as strength develops.