Science Proves the Mind-Muscle Connection

Back in 2015, a group of Danes, led by exercise phys guy Joaquin Calatayud, recruited 18 young, resistance-trained men and got them to bench press on three separate occasions. (1)

Each time, the participants’ triceps and pecs were wired up to measure electrical activity. During one trial, the lifters were required to just bench press, la di dah, without paying any particular attention to the task.

The second time, they were asked to think on their triceps. The third time, their pecs. Both trials were an example of “internal focus.”

When the lifters focused on their triceps, their electrical activity increased. When they concentrated on their pecs, they too downright crackled with increased electricity.

The researchers repeated these three lifting conditions with loads that approximated 20, 40, 50, 60, and 80% of the subjects’ pre-determined 1RM in the bench press.

Oddly enough, it only worked up to 60% of 1RM. There was zip activation at 80%. And it wasn’t a matter of a linear decrease between 60% and 80%. The increased activity just completely dropped off the cliff once they used weights heavier than 60% of 1RM.

So great, thinking about the muscles, at least the triceps and pecs, appears to increase activation and would likely lead to increased hypertrophy, but an interesting thing happened when I started to look for other studies that might have supported the Danes’ findings.

It appeared that while thinking about the exact muscles being used in a movement (internal focus) might lead to increased hypertrophy, thinking about just moving the g-damn weight itself (external focus) appears to lead to increased strength, both acute and long-term, especially where lower-body movements are concerned.

These revelations about external focus and increased strength were revealed in a recent meta-analysis conducted by Jozo Grgic, a Croatian researcher working out of Victoria University in Australia. (2)

Grgic compiled 10 studies that compared the effects of internal focus and external focus on strength.

Let me give you an example of what kinds of concentration cues they used so you better understand what I’m talking about. External focus instructions ranged from researchers telling the participants to “Focus on pushing the ground as hard and fast as you possibly can” (while doing an isometric mid-thigh pull) to the generic, “Get the weight up!”

Examples of internal focus instructions ranged from “Contract the vastus medialis oblique whilst generating maximum effort” to “Squeeze the muscle!”

Quite unequivocally, external focus was the clear winner, at least as far as increased strength.

This whole bit about external and internal focus is integral to what’s known as the “constrained action hypothesis” (Wulf, 2001). It posits that concentrating on only one component of a movement (e.g., one muscle), as is required during internal focus, might constrain the nervous system and hinder performance. Using external focus might allow the completion of the task without leaving out any of the major muscle players.

Sure, makes sense. If Spiderman lifts a fallen girder off Gwen Stacy, he doesn’t think about activating his vastus lateralis; he just focuses on lifting the damn thing.

This strategy would, of course, lead to better performance and, ultimately, increased strength.

It also helps explain why Calatayud’s internal-focus bench press study failed to show benefits after using weights that were over 60% of 1RM. The extra effort involved to move such a heavy weight made selective activation of the muscles difficult, probably “because of the greater force production and motor unit recruitment required to lift heavy weights.”

Based on the published studies, it appears that external focus works well for increasing strength in the short and long term, particularly for lower body movements (if only because there haven’t been enough upper body studies to come to any conclusions).

However, based, at least on the work of Calatayud and a couple of others, using internal focus – concentrating on the muscle itself – appears to work well for increasing hypertrophy, at least when using weights that are 60% of 1RM or below. (The few studies that used internal focus on lower body movements didn’t show much promise.)

So, internal focus for upper body hypertrophy and external focus for lower body strength.

But that brings us to the actual verbal cues used by the researchers to get the participants to focus, either internally or externally. I doubt that you truly need some geeky personal trainer or well-intentioned fellow meathead yelling at you for external and internal focus to work.

To employ internal focus and trigger hypertrophy, simply think about your muscle, whether it be the biceps, triceps, pecs, or, hopefully, any upper body part.

Alternately, if additional strength is your goal, you can think about the movement itself. For instance, think about any of the various cues or instructions you’ve heard over the years that pertain to lower body lifts:

• Focus on pulling the bar up or focus on pushing the floor away from you (deadlifts).
• Focus on driving the bar to the ceiling (squats).
• Get the weight up! (squats and deadlifts).

The key, in this instance, is to focus on the task at hand instead of the muscles being used and not, hopefully, SQUIRREL!