| An obvious point being over looked here is that there is no 'upper' and 'lower' chest. The entire muscle contracts as one unit. To increase any part of the chest then you must increase the whole of the chest.
The chest is made up of pectoralis major and pectoralis minor. Pectoralis major is the visible muscle , and the pectoralis minor is an underlying muscle neither afects upper or lower portions of the chest.
Changing angles will recruit very few different fibres. All I can say in favour of angles is that the stretch of the muscle fascia at certain angles may allow for greater growth in this area, but there is no hard evidence for this.
Another point is that anything beyond around 30 degrees incline will shift emphasis dramatically towards shoulders.
I hope this post is taken as it is intended, as I would hate to see any more peope wasting hundreds of sets on incline bench with low weights or at too high an angle to achieve upper chest growth with no results. |