You’ve probably heard of it: mind-muscle connection. But what is it exactly? Does it exist at all or is it a myth, as there are so many untruths circulating in the world of strenght sports?
Well, that sounds a bit strange: thinking about your muscle when you train it. Suddenly you see a drooling Pluto in front of you with a thought bubble with a large bone in it. Yet scientific research has shown a connection between mind and muscle, based on electromyography (EMG), or the electrical activity of the muscles.
It concerns a series of investigations that have been listed by coach Menno Henselmans:
- Calatayud et al. (2016);
- Paoli et al. (2019);
- Fujita et al. (2019);
- Fujita et al. (2020);
- Calatayud et al. (2018);
- Daniels et al. (2017);
- Nadzalan et al. (2020).
In these studies, two groups of strength athletes were always compared: one performed an exercise without instruction, the other was asked to isolate a specific muscle group, for example the chest or triceps with the bench press.
The results indicate a clear trend in decreasing effectiveness of attentional focus at higher training intensities. With a low training intensity, there is indeed something of a mind-muscle connection perceptible, but the effect disappears as you train more during muscle failure and/or train with heavier weights. Explosive lifting also seems to negate the effects of mind-muscle connection, as Calatayud et al. pointed out.
And training experience doesn’t seem to improve our ability to isolate muscle groups by focusing on them, Daniels et al showed.
The fact that the effect of the mind-muscle connection is limited during heavy or explosive training is, according to Henselmans, due to the motor cortex – the part of our brain that coordinates movement. Most movements, such as walking, are so complex in terms of muscle recruitment patterns that our conscious mind can’t control this task nearly as well as you can intuitively do. Just thinking about a complex movement like running while doing it decreases movement efficiency. This reduced efficiency is also what happens when we use internal signals, such as focusing on a specific muscle.
MUSCLE GROWTH STUDY
Aside from muscle activity, what about muscle growth? Unfortunately, we only have one study that has tested the effect of internal cueing on muscle growth. This is a study by hypertrophy expert Brad Schoenfeld (2018).
Schoenfeld researched two types of focus during power sports: internal and external. Let’s take single bicep curls as an example. With bicep curls, you target, you guessed it, your biceps. Your biceps is responsible for bending your forearm, or more precisely, for the bend in your elbow joint. So when performing bicep curls, it is essential that there is only movement in your elbow joint and that you do not swing the weight upwards by engaging your shoulder joint. This is similar to how people engage their hip joint when performing cable rows or lat pulldowns, exercises that target your back, while the only movement should be in your shoulder joint and elbow joint.
Now there is a significant difference between focusing on the movement and focusing on the muscle responsible for the movement. For example, in biceps curls, do you focus on bending your forearm or on the muscle in your upper arm, the biceps, that is responsible for this movement? In fact, this is a matter of perspective: are you focusing on the cause – the muscle – or the effect – the movement? Schoenfeld calls focus on the muscle internal focus, focus on the movement external.
In principle, the external focus seems to be the most important in performance sports. And even in strength sports you can’t really do without an external focus. With complex exercises like the deadlift and squat, where many muscle groups and muscles work together, it is important to focus on the individual movements to perfect the entire exercise. After all, the exercise consists of several movements – bending your hips, knees and so on. Only when you have mastered each ‘separate’ movement, you have mastered the exercise. Think of it as the loose pieces of a puzzle falling together.
Nevertheless, Schoenfeld’s research seems to provide tentative evidence that internal focus is also important, at least for muscle growth. It turned out that the studied group of students who applied internal focus to biceps curls recorded significantly more muscle growth than the group who focused externally. With leg extensions however, the outcome was different: no significant difference in muscle mass was found for the quadriceps. Schoenfeld says that may be because it’s easier to focus on your biceps than the quadriceps. This is in line with what the participants also stated at the end of the study. It should be noted that these were untrained subjects who trained at a relatively low intensity. It is therefore not said that the results automatically also apply to advanced bodybuilders who complete heavy workouts. The EMG studies suggest not, as we have already seen.
The mind-muscle connection is a well-known concept from the bro science of bodybuilding. However, the scientific basis for this is limited. There is some evidence that when you train hard, we can’t increase muscle activation any further, because it’s already maxed out. Only with submaximal training would we be able to benefit somewhat from a mind-muscle connection.
The existing research suggests that subjective and objective muscle activation are not consistently aligned and there are clearly many cases where the degree to which we feel a muscle does not correlate with muscle activity or tension.
A good example is the recent study comparing the squat to the hip thrust with regard to the glutes. It found that all participants felt hip thrusts better in their glutes, yet hip thrusts were objectively no more effective than squats for the glutes.
We also seem unable to significantly isolate muscle groups by focusing on them during high-intensity exercise, even as experienced strength athletes. During intense training, our motor cortex automatically optimizes muscle activity levels to maximize performance. Research shows that focusing on performance and technique are both more effective than focusing on the mind-muscle connection.
Also remember, if how well we feel a muscle is the best determinant of muscle growth, we should all be aiming for the “pump” and muscle soreness. But you could already read in this article that these are not decisive for muscle growth. It is primarily about the mechanical tension you create. How an exercise feels is certainly a consideration, but you shouldn’t blindly trust that the degree to which you feel an exercise in a muscle is a direct measure of the amount of muscle you gain from it.
All in all, research and logical thinking make it clear that the mind-muscle connection is not really ‘a thing’ for the bodybuilder.
Originally published April 27, 2016, revised August 30, 2023.