rods and casting

It doesn't matter what casting style you use, the power/loading needed to cast a lead can come from only three places:

Lead only:
Loading the rod against the lead alone.
No physical input at all. A slow cast, so timing is not that critical to success and is suited to slow parabolic action rods.

Lead + speed
Using body and rotation speed to generate more load against the lead during the cast. A faster cast in which timing starts to become more critical and is suited to medium-slow through medium-fast action rods.

Lead + speed + body strength
Using body strength and speed to load the rod.
Timing and strength/leverage are highly critical. This is how fast ultra-fast action rods need to be cast but is less suited to most fishing situations than the previous two examples.