Peter: " If you run a mile you may well be winded but that does not mean most of the effort was provided by fast twitch fibers"
You walk a mile - only slow twitch fibers are recruited. You may or may not be winded. No fast twitch fibers are recruited.
You jog a mile...you are probably winded more. Perhaps some fast twitch IIa fibers are recruited- depending on how fast you jog. But fast twitch IIb are most likely not recruited.
You sprint a mile breaking it up into 100 yard dashes at the maximum speed you can run...with a 15 second interval between sprints. You are way more winded, and both fast twitch fibers are recruited.
You swing a golf club slow at 1/10th normal speed for 25 reps. No fast twitch muscles are recruited.
You swing a golf club slow at 1/2 normal speed for 25 reps. Perhaps fast twitch I fibers are recruited.
You swing a golf club as fast as you can. Fast twitch IIa and IIb fibers are recruited.
Peter - "If a real swing is using different muscles than a slow speed swing then one of them is incorrect (or perhaps both)."
I said - "To swing as fast as I can, some muscles are used now perhaps that weren't used before, and for all muscles used, it is much more likely that fast twitch fibers are being recruited to complete the task."
I didn't say different muscles were used, I said some "perhaps" some were used that weren't in a slow motion swing. Sort of like the "push off" with the trial foot is more "in play" in a fast swing than it is in a slow swing...Ideally the same muscles are used for both slow and fast swings.
Peter - "You should be more tired doing full speed swing vs slow because you are using more energy. More energy does not necessarily mean it comes from a different source."
Different activity requires different muscle fibers be brought into play, and they use different energy sources and metabolic processes. Slow twitch fibers utilize oxygen to create fuel (ATP), and triglycerides are their main fuel source. They are very efficient at utilizing oxygen, thus, they have a high endurance factor. Fast twitch fibers create ATP by anaerobic metabolism, have glycogen as their main fuel source, and deplete their energy very quickly, thus have a low endurance factor. Moving from a state of relaxation to swinging a golf club over a 10 second span vs a 1 second span is IMO two very different things, requiring the use of the same muscles perhaps, but not the same muscle fibers. The 10 second swing needs only slow twitch fibers, while the 1 second swing needs fast twitch fibers.
So as Herbert has said this is all fun and interesting, but the the thing is...what do we do with this info? How can we utilize this to build a faster more powerful swing? What are the implications for training and practice? If you train slow and only slow, will your real swing be less powerful than it's potential? If you trained in a way that encouraged the development of muscle fibers that are used for generating short bursts of explosive power - will you swing with more power? In other words to be fast should you train fast?
I have pretty much settled on the fact that to realize your maximum power you must train for it beyond what The Blueprint ( in it's current edition ) and Bertholy prescribe. You must train fast to be fast. As to how to accomplish that, and what is the most effective way...well, for me anyway, a bit like Columbus sailing into the horizon...and there are a lot of folks out there ready to snatch up your money to show you how.
Pretty much decided that another section needs to be added to the The Blueprint....but still have some lab work to do!
"A Blueprint For Golf Excellence"
Never quit til you have a swing you'll never forget!