For decades, bodybuilders have emphasized the importance of the mind–muscle connection. From Arnold Schwarzenegger and Kai Greene to modern bodybuilders like Chris Bumstead and Nick Walker, each generation has spoken about the value of intentionally feeling the muscle you’re training, rather than simply moving the weight and counting reps.

​Is there any merit to these claims?

In the scientific community, what bodybuilders call the mind–muscle connection is referred to as having an “internal focus.”

In contrast, directing your attention toward moving the weight and completing the reps is known as an “external focus”.

It would be the difference between me coaching you to "stretch" and "contract" the chest while dumbbell pressing — Internal Focus = Mind to Muscle Connection. 

Compared to instructing you to "DRIVE!" or "PUSH!" on your last few reps — which biases performance and completion of reps = External Focus.

There’s far more research comparing internal and external focus in relation to performance outcomes, and collectively, the evidence tends to favour an external focus for improving strength and overall performance.

There isn’t much research directly comparing internal and external focus when it comes to building muscle (hypertrophy), but here’s one important study worth noting.
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In 2018, researchers examined how directing your attention — either internally or externally— could influence strength and muscle growth.

Thirty untrained men trained for eight weeks, performing two single-joint exercises: barbell curls for the arms and leg extensions for the quads. These movements were chosen because isolating one muscle makes it easier to control the study and ensure consistent focus.

Participants trained three times per week on non-consecutive days, completing 4 sets of 8–12 reps per exercise. All sessions were supervised by certified strength coaches to maintain proper form and consistent cueing.

The only difference between groups was how they were coached:

– Internal focus group: told to “squeeze the muscle!” — emphasizing the feeling and contraction of the working muscle.

– External focus group: told to “get the weight up!” — emphasizing the outcome and performance of the lift.

Each set was performed to failure, with a 2-second controlled lowering phase and 2 minutes of rest between sets. Weights were adjusted weekly to keep lifters within the 8–12 rep range and promote progressive overload.

After eight weeks, the internal focus group showed a significantly greater increase in biceps thickness, roughly 12% vs. 7%, favouring the internal cue.

For the quads, however, differences were minimal, showing only small or trivial effects between groups

The authors suggest that humans may naturally possess a stronger mind-to-muscle connection in the arms than in the legs, largely because we use our arms more frequently in daily activities. In the study, participants in the internal focus group reported that it was easier to concentrate on contracting their biceps compared to their quadriceps. The researchers proposed that this difficulty in isolating and “feeling” the quads likely stems from lack of training experience, since all 30 participants were untrained individuals.

​Overall, this may help explain why the study found no significant difference between groups for quadriceps growth in the final results.

Speaking from both personal and professional experience, I’d say absolutely yes.

If your goal is to build muscle strategically or pursue bodybuilding, developing a strong mind-to-muscle connection is essential. It helps ensure the right muscles are doing the work instead of letting stronger or more dominant ones take over. Over time, this leads to a more balanced, symmetrical, and aesthetic physique and saves you years of unlearning poor movement patterns.

While more research and studies are still needed to fully understand its impact, early findings, along with years of real-world experience from athletes and coaches, suggest that the mind-to-muscle connection plays a meaningful role in building muscle.

From my experience coaching clients, those who learn to truly feel the muscle they’re training don’t just get stronger at moving the weight — they build more muscle where it truly matters.

On the other hand, if your goal is to get stronger, the mind-to-muscle connection can still be useful, during your accessory work where the goal is to build specific muscles that support your main lifts.

For your primary compound movements such as the squat, bench, or deadlift, you’ll benefit more from adopting an external focus, directing your attention toward performance and bar speed rather than the individual muscle.

If this kind of science-based approach resonates with you, let’s take it a step further.

I offer a free Foundations Call where we’ll break down your current training, identify where you can improve, and build a plan that actually fits your life.

​Book your call today and start training with intention

Below are the key research studies and peer-reviewed articles referenced throughout this post. Each provides scientific context for the principles discussed on attentional focus and the mind–muscle connection.

Citations:

1. Schoenfeld, B. J., Contreras, B., Vigotsky, A. D., Golden, S., Alto, A., Larson, R., Winkelman, N., Paoli, A., Sonmez, G. T., & Krieger, J. W. (2018).

Differential effects of attentional focus strategies during long-term resistance training.
European Journal of Sport Science, 18(5), 705–717.
Available on PubMed: PMID: 29533715.

Summary: This peer-reviewed study examined how internal versus external focus strategies influence muscle growth and strength over an eight-week resistance-training period. Results showed that an internal focus led to greater biceps hypertrophy, while overall strength gains were similar between groups.

2. Schoenfeld, B. J., & Contreras, B.

Attentional Focus for Maximizing Muscle Development: The Mind–Muscle Connection.
Strength and Conditioning Journal, 40(2), 27–33.
Full PDF available on Bret Contreras’ official site.

Summary: This practitioner-oriented article reviews the scientific evidence on attentional focus, explaining how emphasizing the sensation of the working muscle can enhance hypertrophy. It also provides practical guidance on applying the mind–muscle connection within evidence-based training programs.