this is an age old argument of course can you target parts of a muscle. The argument goes that you can either contract a muscle or you dont, you cant contract part of a muscle OR you can target parts of a muscle....
Lets look at this: you CAN ONLY contract a "muscle fiber" the fiber itself either is contracted fully or it is NOT contractred. THAT is where the first argument above fails because it is NOT the muscle itself you contract but the muscle fibers. AND all muscle fibers for every muscle do not start and end at the same EXACT place.
The bicep has two muscles, the triceps have 3, we have the brachalis. For the thigh, we have the Quad(as in4) cepts....
The chest has slabs and slabs of muscle.....
Different exercises and angles will hit certain areas of SLABS better than others.....
I used the example of Steve Reeves hercules, and Vince Gironda. I almost exclusively used to do parallel dips for chest, wide elbows, bent forward , thru my teen years. I had the outer and lower developed and NOTHING really for the inside or the upper. You can feel a peak contraction, a harder contraction at certain angles for certain parts of teh muscle better and why is that? Awell that part of the muscle is being worked out harder at the time, regardless of whether there is a casual assist from teh rest of he muscle. When we damage muscle from working out, doesnt the muscle product IGF-1? Is not the damage relative to the amount of stress the muscle endured? I have recently been doing ped deck flys with a slight bias with chin on chest and shoulder off pad, back slightly rounded and I hit the upper chest, so much so, I can do ped deck til complete failure and immediately change this angle to reflect the above and go for almost a completely full set again! Slightly different angle, Yes, the whole muscle probably contracts but he range of motion for parts of it is full contraction, for other parts of the muscle it is barely a range I am starting to get upper chest develpment when I never had much if any before.
People do spider curls or peak contraction exercises to bring out a peak in a muscle and why? Cuz they WORK to do just THAT! Regardless of the reason why , the phisiology, it doesnt matter, wah matters is a part of the muscle that did not respond to other angles or exercises responded overwhelmingly more, targeted, on this one even if the entire muscle group has fibers within it assisting to some degree or another!
Abs, you do lower and upper, why bother? cuz altho the entire grop flexes, marts of it is stressed more and anyone who has done any lower abs will tell you, (lol, everyone here of course), the net day, they feel it in that targeted area MORE than if they had just done upper abs work.
This same argument goes for can you spot reduce, the old bodybuilders all felt they could and there is evidence today that states taht a muscle that is arobically worked out, (high reps for abs or obliques) will tend to use the fat that is closest to the targeted areas requiring the energy at the time.
For those who are not convinced, take one workout for chest and exclusively do dips and cross overs. Take another one and exclusively do inclines, where you are sore is where the damage was done....
Gazhole, lol... you are funny but to be fair, wide grip chinning vs shoulde width does focus more on targeted areas EVEN tho the entire back /lats are contracting, it does cuz parts of the back (some fibers) see a full contraction, some dont cuz of the angle while T-bar rows vs wide bent over rows, one is outer lats, one is inner back cuz the wide grip rows allows you to fully contract the inner back while the t bars you just get the initial movement. It is like doing partials for the inner and full reps for the outer....
The traps.... various places of inertion of the muscle, do shrugs vs doing reverse peck deck or wehe you pull up... different part of the muscle.....
The idea behind BODYBUILDING is to shape, contour each muscle within your own genetics 9where and how muscles start and end) vs a weightlifter or power lifter who have rugged muscles but none would ever win a bodybuilding contest cuz size, unbound size with just bulky shape doesnt win contests.. fully developed muscles from al angles does.
This is my take...
Think muscle fiber not muscle and think slabs that start and end not always in the same place and think partial rep for some vs full peak contraction for others depending on angle.
The proof is in the different body types creted by different systems. event eh high rep vs low rep fast vs slow twitching the muscle selectively recruits certain fibers along a spectrum
