If you surveyed bodybuilders around the world, I’m sure you’d find that the bench press is the most popular lift everywhere. All bodybuilders, professionals, amateurs and beginners perform bench-pressing movements. Most love to bench because it’s considered the ultimate measurement of upper-body strength.

It’s more difficult to perform electromyographic analysis on the chest muscles than on any other muscle groups in the human body. The EMG signal determines the amount of electrical activity that’s generated by the target muscle or muscles at a given time. Because of where the electrodes are positioned on the chest, however, the machines also pick up electrocardiogram (EKG) disturbances from the heart muscle.

Researchers have developed several methods of separating the two signals. One technique is to pick up the EKG signal, change its polarity and after suitable amplification feed a current back to the body surface to cancel the currents caused by the electro-cardio field.

Another method takes advantage of the fact that the EKG wave for the time period is approximately constant and much shorter. The highest peak of EKG wave is easy to identify either in the EMG recording or through a separate pickup electrode. To eliminate the EKG disturbance, a suitable portion of the recording is simply cut out. Research has shown that in EMG recordings for workload investigations this loss of recording time doesn’t cause any serious loss of information (Kumar and Mital, 1984).

Methods

Six healthy volunteer athletes were recruited, three men and three women. All the subjects had at least two years experience in strength training and had never practiced performance doping.

They were tested on two separate days. On the first day their one-rep maxes for the six exercises were determined. Each athlete performed a warmup of four reps at 50 percent of one-rep max, three reps at 80 percent and two reps at 90 percent, with a five-minute rest after each set. The athletes then performed three one-rep maxes for each exercise, taking a five-minute rest after each trial.

On the second day the subjects did 80 percent of one-rep max five times, interspersed with three-minute rest intervals. The following exercises were tested:

1. Decline dumbbell presses
2. Decline barbell presses
3. Pushups between benches
4. Flat-bench dumbbell presses
5. Flat-bench flyes
6. Pec deck

Electromyographic activity was measured during all exercises. All EMG data was rectified and integrated for one second, which is referred to as JEMG. Researchers designated the exercise that yielded the highest IEMG determined at one-rep maximum as JEMG max for the pectoralis major, and the researchers determined IEMG max by taking the average of the three one-rep maxes for each exercise. Expressed was the IEMG values obtained during 80 percent of one-rep-max sets as a percentage of IEMG max, and the researchers determined IEMG at 80 percent of one-rep maximum by taking the average of the five 80 percent trials.

Results

The data indicated that there was no significant difference between the main exercise effects on the pectoralis major for the decline dumbbell press (93 percent) and the decline barbell press (89 percent). In comparing the decline dumbbell press with the pushup between benches (88 percent), the difference starts to be significant, and it becomes even greater with the flat-bench dumbbell press (87 percent), flat-bench flye (84 percent) and pec deck (76 percent). Therefore, decline dumbbell and barbell presses produce the greatest amount of electrical stimulation and are the best choices for training the pecs major.

Group	Exercise	% IEMG Max	% Difference
6 athletes	1) Decline dumbbell presses	93	1 to 2:4
	2) Decline barbell presses	89	2 to 3:1
	3) Pushups between benches	88	3 to 4:1
	4) Flat-bench dumbbell presses	87	4 to 5:3
	5) Flat-bench flyes	84	5 to 6:8
	6) Pec deck	76	N/A
Pectoralis major exercise analysis. % IEMG max indicates motor unit activation.

Conclusions

Although the flat- and incline-bench presses are the most popular lifts in the world, science proves that bodybuilders should add decline presses to their chest routines. What’s more, despite the above recommendation, the decline dumbbell press does produce 4 percent more stimulation than its barbell counterpart, making it potentially that much more effective.