Dumbbell Flys… Why?

Pec Training, every guy’s priority. If it’s your priority then say goodbye to this exercise. Problems associated with this exercise:                                                                 -Maximum resistance at the bottom of the range and zero at top. A bad resistance profile, not what you want if you are trying to target a muscle group effectively.
Ineffective resistance range for pectoral stimulus and development
-Anterior shoulder joint capsule wear                                                                         -Biceps Tendon strain
-Poor resistance to strength profile
-Increased inertia increasing deceleration requirements
-Chance of soft tissue, (tendon, ligament, bursae), premature degeneration
Range of motion is usually excessive, (going too deep), increasing detriment. Looking at the fly from a lying position at the end of range when your arms are open out to the side, the weights application of resistance is greatest because of its distance from the axis, (shoulder joint) and gravity’s application. The joint is also placed in its weakest, most fragile, and vulnerable position and gravity is applying its maximum resistance.

Not good.

As you move the weight upward through the range of motion, back to the top and over the chest, the resistance deceases due to gravity’s effect. By the time you reach the top, you are in a balanced position with the weight directly over the shoulder where it applies no resistance to the pec at all. Put your hand on your buddy’s chest and see how contracted the muscle is. A muscle is in its strongest position approximately half the way through a range. Therefore, the weight should correspondingly apply its maximum resistance there as well. This is called matching the strength and resistance profile. With the dumbbell fly however, the resistance is maximum at the bottom of the range and decreases upward, whereas the muscle is at its weakest and gets more capable at producing force on the way up.

The shoulder is not a ball and socket joint like the hip, but relies upon muscle, ligament, and tendon for support. It is much more fragile and its given mechanics should be respected.

Another thing to remember: the pec is not being isolated; it is impossible to work the pec without the anterior portion of the shoulder, delt, helping out.

Consider also deceleration of the weight. Compared to the dumbbell or bench press, it takes relatively four times the effort to stop the weight on the way down because the resistance travels roughly twice the distance.

It’s the old story of “it’s not the starting that’s hard, it’s the stopping.”

I can’t tell you the number of exercisers I have seen on a daily basis performing flys at a rapid tempo, violating the joint’s established and effective range of motion, lifting too much weight with absolutely no control and then getting up and rubbing their shoulders. In fact an instructor of mine used to say that Icy Hot was part of many a lifters gym bag arsenal.

The point to get across is just because an exercise has been done for years and you see a lot of people doing it does not mean it is beneficial or un-harmful.

Here is a great option for pec emphasis. CABLE FLYS. On an adjustable cable crossover, adjust the height of the pulleys to shoulder height. Stand forward of the station and assume a staggered, (one foot forward), stance. Keeping the elbows slightly bent and locked, wrists slightly angled, lead with the thumbs and bring them together. Keep your chest up and ahead of the shoulders. Lower the pulleys a couple of notches and start from six inches below shoulder height and bring up to eye level to emphasize upper, (clavicular), pecs. Or, raise the pulleys up to head level and come down slightly below chest level to bring in the mid-low, (sternal-costal), pecs. Try moving forward of the station at different increments to change the application of resistance in different parts of the range. This can also be performed in the Supine position, (on the back on a bench), but I prefer standing simply to allow the shoulder baldes move more freely without hinderance form the weight of the body into the bench.                             Using resistance tubing is also an option but it must be anchored roughly twice the width of your shoulders, or outside the width of your elbows at 90° when 90° away from the body. Otherwise, there is no resistance applied to the pecs, you are starting from a balanced position. Use 2 separate tubes mimicking a cable crossover or perform one arm at a time. Single arm flys also make a great option.