THE BEGINNERS GUIDE TO TRAINING pt2: THE CHEST

 So we're finally back in action and here is our first article - Following where we left off from PART1, which you can find here: THE BEGINNERS GUIDE TO TRAINING pt1

So without any more unneeded babbling. Let's get going.
WHAT WORKS WHAT? 
THE CHEST (Pectoralis Major and Minor)

Pressing/Pushing and Fly movements

The Pectoral muscles help keep the arm attached to the trunk. When it comes to the arm, the pectorals help with: 

• FLEXION of the Humerus
• ADDUCTION of the Humerus
• MEDIAL ROTATION of the Humerus 

To view some of those movements: 

http://www.youtube.com/watch?v=u_5I1yj5jjM 

The Pectorals are usually separated into 3 different ‘parts’: 

• Upper (clavicular)
• middle
• lower

which is why you see people benching in different styles – Incline, flat and decline. All ‘parts’ will be hit when doing a movement that activates the chest, however the amount of activation will differ with different exercises that target those specific areas – we’ll get more into inclines and declines and all of that in a little bit.

When the pectoral muscles function together, they work with Horizontal Adduction – Bringing your arms across your chest.

Exercises, that activate the Pecs, mainly involve PUSHING/PRESSING movements – Bench PRESS, dumbbell PRESS, PUSH ups – see where I’m going with this? So now when you see something and it involves PUSHING or PRESSING, you know that the main mover is the Pecs/Chest and if anyone tries to convince you that doing a push up will help build your calves (extreme exaggeration, I know), you can backhand them right there on the spot.

Now apply gravity - If you’re on your back and you’re performing a dumbbell fly, you’re fighting the force of gravity that is pulling the weight earthbound, so to put it in simple terms, you’re pushing the weight up - So when you’re arms move a weight across or pushing it away from your chest, your pectorals are the main functioning muscle group 

Now, when performing movements that involve the chest, you must remember that it’s not the only functioning muscles. It takes multiple muscles that function in synergy to help you lift/move an object

For instance, the Bench Press:

The main mover would be your Pectorals, they would be assisted by the:

Triceps – which help extend the elbow, thus helping push the weights up (bend your elbow and now straighten out – that’s help from your triceps – if you over extend [hyperextend], you’ll feel your tricep pulling quite nicely) 
Deltoids (anterior: front part of your shoulder) – help with stabilization and movement 

These are just two of the main muscle groups that are functioning; other muscles that help with stabilization include the core, parts of the Trapezius (traps) and smaller rotator cuff muscles.

So by noting this, it should now be obvious that if your triceps are finished after being blasted the day before and today you feel like it’s a chest day, don’t be surprised if your lifting isn’t of top quality. WHY? Because your triceps help with the extending of the elbow and as they’re buggered, that’s going to be harder – This is where program design comes in and we’ll touch on that after the body parts have been discussed 

Is there a way to remove the amount of tricep work done?

Yes! Remember, the triceps help with extending of the elbow – Remove that and we’re left with a FLY movement which can be used to pre-fatigue your chest or used after your triceps have given in. 

HITTING THE DIFFERENT PARTS 

Earlier, we talked about incline, flat and decline which help boost the activation of certain parts of the pectoral muscles.

Thanks to EMG (electromyography) scans, we know that when performing any variation of the bench press, will still target all the muscles however:

Incline – Increased activation of the upper pectorals (clavicular portion) with less activation of the other fibres (middle and lower) – this is on a 45 degree incline.

Flat – will hit all fibres of the chest with (rather averagely)
Decline – Will hit the pectoral major and lower end fibres and decreased activation of the upper chest

There reaches a point on inclines (and I would assume the same goes for decline) that if you increase the incline too much, the amount of work that is placed on the upper fibres, will soon shift to the deltoids and it pretty much becomes a Shoulder Press. FAR TOO MANY TIMES have I seen some avid lifter doing shoulder press, claiming that it’s hitting the upper chest fibres – THIS IS NOT TRUE!There’s a simple solution to this…WALK AWAY and go train correctly.

SUMMARY

So remember, if you don’t know what the exercise does – run through it. ARE YOU PUSHING SOMETHING? (with your upper body/arms), then it’s your CHEST that’s being worked

I hope this helps. Feel free to ask any question
TAMBE ‘doc’ JOESHA

Additional references: 
http://suppversity.blogspot.com/2011/07/suppversity-emg-series-musculus.html