There are many different exercises to train the pectoralis major, but what are the most effective chest excercises? For those who want to increase the size of their chest muscles it is important to train all different parts of the pectoralis major. This article reviews which exercises target the different parts of the chest muscle best. In addition, muscle activity of assisting (synergistic) muscles will be reviewed as well.

The chest muscle which is also known as the pectoralis major is a very important muscle with different functions. It is the muscle group that shapes the chest and because it is a large muscle group it consumes a lot of energy so it is important to train this as well when you want to lose weight. The pectoralis major is involved in all movements in which the arm is brought towards the body (adduction and horizontal adduction) and in which the arm is raised forwards (anteflexion).

Figure 1: Anatomy of the Pectoralis major and assisting muscle groups.

Anatomy

The pectoralis major can functionally be split into two parts: pars clavicularis and pars sternocostalis. (Some sources report an additional pars abdominalis however there is no EMG study performed that registered this part and it does not differ much in function from the sterocostal part). The pars clavicularis is located in the upper part of the pectoralis major, just beneath the collar bone (clavicula). The pars sternocostalis is located below pars clavicularis on the ribs and the sternum.

The deltoideus also known as the shoulder muscle can be split into three parts: pars clavicularis, pars acromialis and pars spinalis. Pars clavicularis is located next to the collarbone (clavicula) and the pectoralis major. Pars acromialis is located at the side of the shoulder (lateral) and is attached to a point of the shoulderblade (acromion). Pars spinalis is located at the back (dorsal) of the shoulder. In this article only the first two are of importance. Pars clavicularis often works in unison with the pectoralis major and pars acromialis stabilizes many movements of the shoulder.

In addition the bicepts and triceps brachii are depicted because these are often used in movements in the shoulder joint and are therefore important during chest exercises. De biceps brachii is located at the front of the upper arm and bends the elbow (flexion) and brings the upper arm forward (anteflexion). The tricpes brachii is located at the back of the upper arm and extends the elbow. The triceps brachii is therefore very important during pressing movements.

Differences in muscle activation due to exercise stability requirements

In what way do stability requirements of an exercise influence muscle activation? Pressing two dumbbells, a barbell or the bar in a Smith Machine all place different demands on muscles that stabilize the joints during the same basic movement. But is a less stable exercise such as the dumbbell press more effective for the main muscle group, the pectoralis major, than pressing against a bar that can only go up or down (Smith Machine)?

The results of different studies are depicted in the tables below. To allow comparison of different studies, a ranking of exercises has been made for every muscle group that was studied. When two exercises are of the same rank, they activate that muscle group equally.

In a study in which muscle activity during the Barbell Bench Press was compared with muscle activity during the Smith Machine Bench Press there only was a significant difference in the activation of pars acromialis of the deltoideus. (See also Table 1) In other words, both exercises activated the pectoralis major and pars clavicularis of the delotoideus equally. In addition, there were no differences in the weight that was pressed between both exercises, so all muscles were loaded equally as well.¹

	Barbell Bench Press	Smith Machine Bench Press
Pectoralis major	1	1
Deltoideus pars clavicularis	1	1
Deltoideus pars acromialis	1	2
1 Repetition Maximum	1	1
Table 1: Rank order muscle activation Barbell Bench Press vs Smith Machine Bench Press

A second similar study compared the Barbell Bench Press to the Dumbbell Press and Smith Machine Press. No differences in muscle activation of the pectoralis major or pars clavularis of the deltoideus. There was however a lower activation of the triceps brachii and a higher activation of the biceps brachii during the Dumbbell Press as a result of the greater stability demands of this exercise. The Barbell Bench Press in turn activated the biceps brachii to a greater extent than the Smith Machine Bench Press (See Table 2). However the subjects in this study were able to press significantly more weight, when stability requirements decreased, meaning the Barbell Bench Press allowed more weight than the Dumbbell Press and the Smith Machine Press allowed more weight to be pressed than the Barbell Bench Press.

	Dumbbell Press	Barbell Bench Press	Smith Machine Bench Press
Pectoralis Major	1	1	1
Deltoideus pars Clavicularis	1	1	1
Triceps Brachii	2	1	1
Biceps Brachii	1	2	3
1RM	3	2	1
Table 2: Rank order muscle activation Dumbbell Press vs Barbell Bench Press vs Smith Machine Bench Press

Conclusion exercise stability:

The amount of freedom the studied chest exercises allow did not affect the activation of the pectoralis major. The more unstable an exercise is however, the more assisting and stabilizing muscle groups are activated. It is possible that this limits the amount of weight that is pressed during the exercise which can limits the effectiveness of the training for the pectoralis major muscle.

Differences in muscle activation due to pressing angle

The pectoralis major is a large muscle group with multiple functions. To provide all parts of the pectoralis major with a proper training stimulus, different variations of the bench press with varying pressing angles are performed. The results of a study investigating the effect of pressing angle on the activation of different parts of the pectoralis major are depicted in Table 3. This study compared muscle activity in the Decline Bench Press, Barbell Bench Press, Incline Bench Press and the Seated Military Press. The results indicate that the regular Barbell Bench Press activated both parts of the pectoralis major and the triceps brachii the most. Second in terms of activation of the same muscle groups was the Decline Bench Press. The Incline Bench Press activated the upper part of the pectoralis major as strongly as the Barbell Bench Press. For the middle/lower part of the pectoralis major it was just as effective as the Decline Bench Press. The Seated Military Press is normally used as an exercise to train the deltoideus which can be clearly seen from te results. Activation of the upper part of the chest muscle was comparable with that of the Decline Bench Press and the Seated Military Press activated the deltoideus pars clavicularis the strongest. Both the triceps brachii and the pectoralis major pars sternocostalis (middle/lower) were significantly less activated than in all other exercises. The amount of weight the subjects were able to press, was highest in both the Barbell Bench Press and the Decline Bench Press, next was the Incline Press and the Seated Military Press was performed with the least amount of weight.³

	Decline Bench Press	Barbell Bench Press	Incline Bench Press	Seated Military Press
Pectoralis Major pars Clavicularis	2	1	1	2
Pectoralis Major pars Sternocostalis	2	1	2	3
Triceps Brachii	2	1	3	3
Deltoideus pars Clavicularis	2	2	1	1
1RM	1	1	2	3
Table 3: Rank order muscle activation in exercises with varying pressing angles.

Conclusion pressing angle:

The angle under which a barbell is press greatly affects muscle activation of the pectoralis major and other assisting muscles. The ‘regular’ Barbell Bench Press activates both parts of the chest and the triceps brachii the most. In addition the Barbell Bench Press allows the highest amount of weight. So both in terms of muscle ativation and amount of weight the Barbell Bench Press is most effective. The Incline Bench Press can be an effective means to help develop the thinner upper part of the pectoralis major without training the stronger lower part, which might be interesting for bodybuilders and fitness athletes seeking to improve their physique.

Compound exercise versus isolation exercise

Aside from stability and pressing angle another factor that can influence muscle activation and therefore training effectiveness is whether it’s a compound exercise or isolation exercise. Compound exercises target multiple muscle groups which makes them more suited to enhance sports performance since they simulate natural movements better. In addition, because they target many different muscles, the weakest link is trained best. This can be an advantage in sports performance and everyday living since improving the weakest link improves performance as a whole. However it can also cause incomplete training of the strongest muscles. Isolation exercises are exercises which train only one muscle group. In practice this is virtually impossible becuase there are almost always other muscles active during any movement. However it is thought that they still may exercise the strong main muscle group more effectively than a compound exercise.  One study compared the  Barbell Bench Press with the Pec Deck Machine. No differences were found in the activation of the pectoralis major and the deltoideus pars clavicularis muscles. Naturally the triceps brachii were far more strongly activated during the Barbell Bench Press than during the Pec Deck. The subjects were able to lift equal amounts of weight during both exercises.⁴

	Barbell Bench Press	Pec Deck
Pectoralis Major	1	1
Deltoideus pars Clavicularis	1	1
Triceps Brachii	1	2
1RM	1	1
Table 4: Rank order muscle activation compound exercises vs isolation exercises

Conclusion compound exercises vs isolation exercises

Concerning muscle activation of the pectoralis major both the compound exercise Barbell Bench Press as the isolation exercise Pec Deck are equally effective. However the Pec Deck can be an important addition when the triceps brachii muscle is exhausted by the compound exercises and the pectoralis major has not been trained completely.

Overview pectoralis major activation during different exercises

Finally a study compared nine different exercises for pectoralis major activation (See Table 5). In this study only pectoralis major activation was studied and no difference was made between both parts of the pectoralis major, although according to the description they placed the electrodes on the sternocostal part. The results once again show that the Barbell Bench Press along with the Pec Deck activate the pectoralis major the strongest. In addition the Bent-Forward Cable Crossover proved equally effective, The Chest Press machine was a lot less effective and the Incline Dumbbell Fly’s and Dips were even less effective than the Chest Press machine. The three different forms of Push Ups were the least effective exercises to activate the pectoralis major with no differences between the three different forms. This was probably caused by the fact that the subjects only needed to push up their own body weight and no extra weight to attain a comparable training intensity as in the other exercises. It does indicate that a standard Push Up activates the pectoralis muscle just as much as a Push Up with both feet on a Swiss Ball or in a Suspension Trainer.⁵

	Pectoralis Major
Barbell Bench Press	1
Pec Deck	1
Bent-Forward Cable Crossovers	1
Chest Press Machine	2
Incline Dumbbell Fly’s	3
Dips	3
Suspension Push Ups	4
Swiss Ball Push Ups	4
Standard Push Ups	4
Table 5: Rank order pectoralis major activation in different exercises

Conclusions and advice concerning the most effective chest exercises:

Because the pectoralis major is such a versatile muscle and many of its functions are assisted by many other muscles it is important to select the best combination of exercises so all muscles develop in proportion. Unfortunately only limited research has been done which investigates muscle activation during different exercises. It is therefore not possible to draw conclusions about all chest exercises. However considering the data above the following can be concluded:

Barbell Bench Press:

The regular Barbell Bench Press is in almost all studies the most effective and complete exercise to exercise the chest based on muscle activation during the exercise. In addition this exercise allows more weight to be pressed than other exercises.

Incline Bench Press:

This exericse is an effective alternative for the Barbell Bench Press and can be used as an additional exercise to develop the upper part of the pectoralis major and the deltoideus.

Decline Bench Press:

Almost as effective as the Barbell Bench Press for several parts of the pectoralis major and possibly allows more weight than the regular Barbell Bench Press.

Pec Deck:

Activates the pectoralis major just as well as a Barbell Bench Press but few other muscles are really active. This makes it effective as a last chest exercise to be used when the triceps brachii is exhausted but the pectoralis major isn’t.

Bent-Forward Cable Crossovers:

Another isolation exercise that activates the pectoralis major just as much as the Barbell Bench Press and the Pec Deck. It is a good alternative for the Pec Deck to be used at the end of a chest workout.

Dumbbell Press:

Almost as effective in terms of muscle activation as the Barbell Bench Press, but usually performed with less weight. An advantage the Dumbbell Press has over the Barbell Bench Press is a larger range of motion. A larger range of motion leads to better training results in terms of strength and hypertrophy.

Chest Press Machine:

Altough there is not much data available, this seems to be in the middle of the pack in terms of activation of the pectoralis major. The main advantage of the Chest Press Machine is that people are often able to press larger amounts of weight and it is generally safer for beginners, especially when training at high intensities.

See also:

-How To Increase Muscle Mass Effectively 

References:

1. Schick. E.E., Coburn, J.W., Brown, L.E., et al. A Comparison of Muscle Activation Between a Smith Machine and Free Weight Bench Press. Journal of Strength and Conditioning Research, 2010, 24, 3, 779-784.
2. Saeterbakken, A.H., Tillar, R. van den, Fimland, M.S. A Compariso of Muscle Activity and 1-RM Strength of Three Chest-Press Exercises with Different Stability Requirements. Journal of Sports Sciences, 2011, 29, 0, 1-6.
3. Barnett,C., Kippers, V., Turner, P. Effects of Variations of the Bench Press Exercise on the EMG Activity of Five Shoulder Muscles. Journal of Strength and Conditioning Research, 1995, 9, 4, 222-227.
4. Araújo, V., de, Gentil, P., Oliveira, E. et al. Comparison among the EMG Activity of the Pectoralis major, Anterior Deltoidis and Triceps Brachii during the Bench Press and Peck Deck Exercises. Revista Brasileira de Medicina do Esporte, 2007, 13, 1, 43-46.
5. Schanke, W. Electromyographical Analysis of The Pectoralis Major During Various Chest Exercises. University of Wisconsin-La Cross, 2012.