The Power of the Mind Muscle Connection

For decades, bodybuilders have been preaching the importance of ‘mind-muscle connection’ — the concentration of effort on the particular muscle being worked during an exercise. But: does mind-muscle connection really lead to increased muscle growth in working muscles, or is it all just bro-talk?

The Power of the Mind Muscle Connection

For decades, bodybuilders have been preaching the importance of ‘mind-muscle connection’ — the concentration of effort on the particular muscle being worked during an exercise.

They advocate for instance, the importance of really squeezing the pectoral muscle during a chest press.

But: does mind-muscle connection really lead to increased muscle growth in working muscles, or is it all just bro-talk?

Attentional Focus

First, we have to acquaint ourselves with two types of attentional focus:

Internal focus

Internal focus can be thought of as the same thing as ‘mind-muscle connection’ — it involves thinking about how the body moves, such as the contraction of the targeted muscle, or the movement of limbs around a joint.

The mental picture of squeezing the biceps as hard as possible during a set of bicep curls is an example.

External focus

External focus involves thinking about the environment, such as the weight or the ground. The thought of getting the bar off the ground in a set of deadlifts is one such example.

The current scientific literature has covered the effects of external focus extensively. Researchers have found that when attention is placed on the outcome of a movement, rather than individual muscles, individuals achieve more exceptional performance on tests of athletic ability, and superior motor learning, and skill acquisition over a long-term training period.

This begs the question: what about internal focus — our beloved ‘mind-muscle connection’? Does it offer any benefits to those who choose to practice it?

The “Bros” Have Been Waiting For This

A study that “bros” around the world have been waiting forever to see was finally published in 2018: it aimed to examine whether internal and external focus during training leads to differences in muscle growth and strength gains.


The investigators rounded up 27 young men who hadn’t lifted weights in the past year and randomly assigned them to either an internal focus group or an external focus group:

  • Internal focus — participants were cued to “squeeze the muscle!” on all reps.
  • External focus — participants were cued to “get the weight up!” on all reps.


The study lasted for eight weeks, and the participants did barbell curls and knee extensions three times per week for 4 sets of 8–12 reps to failure. The load was continuously adjusted to ensure they kept within that rep range.


Researchers kept track of muscle hypertrophy through ultrasound readings of muscle thickness of the elbow flexors (biceps and brachialis), mid-thigh (rectus femoris and vastus intermedius), and lateral thigh (primarily vastus lateralis). Investigators ensured that post-workout swelling was not a confounding factor in the measurements as post-training thickness measurements were taken only after 2 to 3 days after the last workout.

The strength gains of the participants were tracked through readings of participants’ force output on an immovable load.

Were The Bros Right?

So — what were the results of the study? Did it show that focusing hard on contracting and squeezing a muscle makes it grow more?

Well, it all depends on the muscle you’re looking at.

In this study, an internal focus did make a difference for the biceps, but not for the quads. How can this be explained? The authors propose that people may not be quite as good at purposefully recruiting and flexing their quads the same way they can flex their biceps on command, which could decrease the effectiveness of the internal focus cue.

When you think about it, this makes sense — how many of us show off our quads when asked to flex? This line of reasoning is further substantiated by the fact that people have higher motor control of their upper limbs than their lower limbs.

But what about advanced bodybuilders who have more conscious control of their quads? Well, it is possible that internal focus might make a relatively bigger difference for them, and their quad development.

Do the findings mean that you should always seek a ‘mind-muscle connection’ through all your exercises for better muscle hypertrophy?

Not exactly — we have to realize that the investigators only looked at single joint isolation exercises in a moderate rep range, and the observed results shouldn’t be extrapolated to heavier compound lifts like squats, presses, and deadlifts.

Applicability of Findings

Heavy compound exercises

You should use external cueing — the focus on how your body is moving relative to space — when going heavy (generally below 8 reps). Examples of heavy compound exercises with many contributions from muscle groups include squats, deadlifts, and presses.

Isolation exercises

You should use internal cueing (mind-muscle connection) with isolation exercises when the goal is to target a specific muscle. Examples of isolation exercises include bicep curls, leg extensions, and leg curls.

Where Do We Go From Here?

The discussed study suggest that we might require a relatively high degree of conscious control over a muscle for the effective maximization of muscle hypertrophy induced by a mind-muscle connection.

It may be helpful to practice flexing lagging muscle groups throughout the day to improve your conscious control of them. Who knows, you may only be a few flexes away from turning into Arnold Schwarzenegger.

Also, the maintenance of proper form throughout all exercises during your strength training session can help with the mind-muscle connection. Proper form and execution ensure that you are recruiting the appropriate muscle groups suited to perform the exercise. You don’t want to involve your traps in lat pull downs, right?

Concerned about your lifting form?

Well, GymStreak is here to help — the platform’s comprehensive database of exercises and their respective 360 degrees’ animation allows you to examine the correct form from all angles. The app layers the animation on top of your surroundings through AR, and you can zoom and change your perspective of it as necessary.

Detailed exercise instructions, tips, and breathing information are also included in the platform.

Well, what are you waiting for? Get all the help you need by downloading GymStreak now!


Ducharme, S. W., Wu, W. F. W., Lim, K., Porter, J. M., & Geraldo, F. (2016). Standing Long Jump Performance With an External Focus of Attention Is Improved as a Result of a More Effective Projection Angle. Journal of Strength and Conditioning Research, 30(1), 276–281.

Schoenfeld, B. J., Vigotsky, A., Contreras, B., Golden, S., Alto, A., Larson, R., … Paoli, A. (2018). Differential effects of attentional focus strategies during long-term resistance training. European Journal of Sport Science, 18(5), 705–712.

Wulf, G., Höß, M., & Prinz, W. (1998). Instructions for motor learning: differential effects of internal versus external focus of attention. Journal of Motor Behavior, 30(2), 169–179.

Wulf, Gabriele. (2013). Attentional focus and motor learning: a review of 15 years. International Review of Sport and Exercise Psychology, 6(1), 77–104.