Flat Bench Press vs. Pec Deck

Here’s a study comparing flat bench press and the pec deck that I found interesting and I thought you might too. What I found interesting is that some people perform the pec deck thinking that this exercise will help “isolate” their pecs and make the muscle work harder when compared to flat bench press. However, as this study shows, that’s not exactly the case.

In the study, researchers had 13 men with weight-training experience perform bench press and pec deck using a load that would allow them to hit 10 reps for each exercise. The researchers then measured the muscle activity of the pecs, front delts and triceps while the men exercised.

What the researchers found was that there was no significant difference in muscle activation in the pecs or delts for either exercise. However, there was significantly more activation in the triceps during the bench press then the pec deck. This isn’t a big surprise as the triceps are not really used during the pec deck. Therefore, while performing the pec deck helps take the triceps out of play, so to speak, it doesn’t technically make the chest muscles work any harder.

So if your triceps are torched and you want to continue hitting your chest then using the pec deck is in an option. (Note: That’s not the only reason you would you use pec deck in your training, but that’s not within the scope of this post.) A better option, at least to the LBC crew, is to use the pec fly machine using a palms down grip. The primary benefit of the pec fly machine with a palms down grip is that it works the chest muscle through its intended purpose or function. That is, horizontally adduct and internally rotate the humerus (the upper arm bone). The pec deck only does the former. Also, the pec fly machine allows for a greater range of motion and a deeper stretch in the start position in comparison to the pec deck. Plus, the pec fly machine allows for more weight to be used. All of this helps place greater stress on the pecs, which can lead to greater chest development.