Building Swing Speed
Here's one way to build swing speed ... wide stance, huge backswing, front foot off the ground, cupped top hand and the let the gorilla eat!
If you want to develop swing speed, then
swing a very light object faster than your normal swing. Since there is no such
thing as a 110% swing, developing swing speed is a matter of first finding your
100% or max speed and then finding your realistic playing speed (probably about
85-90% of your max). Improved swing speed is at least as much about improved
swing mechanics as it is about improved "abilities ... speed, strength,
flexibility". Speed is very slow and difficult to improve even for fit athletes.
Joe Golf needs to look in a different direction.