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Abstract

ATTENTIONAL FOCUS IS A WELL-RECOGNIZED ASPECT OF MOTOR LEARNING AND ITS USE HAS IMPORTANT IMPLICATIONS TO THE FITNESS PROFESSIONAL. THIS ARTICLE WILL DISCUSS HOW ATTENTIONAL FOCUS SHOULD BE DIRECTED TO MAXIMIZE MUSCULAR DEVELOPMENT.
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COLUMN EDITOR: Brad Schoenfeld, PhD, CSCS,
CSPS, NSCA-CPT
Attentional Focus for
Maximizing Muscle
Development: The
Mind-Muscle Connection
Brad J. Schoenfeld, PhD, CSCS, FNSCA
1
and Bret Contreras, MA, CSCS
2
1
Department of Health Sciences, Program of Exercise Science, City University of New York, Lehman College, New
York, New York; and
2
Sport Performance Research Institute, AUT University, Auckland, New Zealand
ABSTRACT
ATTENTIONAL FOCUS IS A WELL-
RECOGNIZED ASPECT OF MOTOR
LEARNING AND ITS USE HAS
IMPORTANT IMPLICATIONS TO THE
FITNESS PROFESSIONAL. THIS
ARTICLE WILL DISCUSS HOW
ATTENTIONAL FOCUS SHOULD BE
DIRECTED TO MAXIMIZE MUSCU-
LAR DEVELOPMENT.
A
ttentional focus is a well-
recognized aspect of motor
learning and its use has impor-
tant implications to the tness profes-
sional. Simply stated, attentional focus
refers to what an individual thinks about
when performing a given movement or
activity . Two primary types of atten-
tional focuses have been identified:
internal and external. With an internal
focus, the individual thinks about bodily
movements during performance. Alter-
natively, an external focus directs the
exerciser’s attention to the environment.
For example, in the squat an internal
focus could be to “squeeze your glutes
as you ascend” whereas an external
focus could be to “drive the floor away
from your body.” This article will discuss
how attentional focus should be d irected
to maximize muscular development.
ATTENTIONAL FOCUS RESEARCH
A compelling body of research indi-
cates that performance-oriented tasks
are optimized by adopting an external
focus of attention. In a recent review of
literature encompassing over 50 pub-
lished studies on the topic, Wulf (12)
found that more than 90% of these
studies showed superior improvements
in motor learning when subjects used
an external compared with internal
focus. Beneficial effects were seen
across a wide variety of activities and
outcome measures, lending strong sup-
port for the use of an external focus
when the goal is to boost performance.
With respect to resistance training, the
performance-based superiority of an
external focus has been attributed to
an enhanced economy of movement
associated with greater force produc-
tion and reduced muscular activity (5).
However, whereas a more economical
movement pattern facilitates better skill
acquisition, it may not be optimal for
muscle development. Indeed, when
the goal is to maximize hypertrophy,
indirect evidence suggests that an inter-
nal focus may be the best approach.
Bodybuilders have long preached the
importance of developing a “mind-
muscle connection” when training. This
internally focused strategy involves visu-
alizing the target muscle and consciously
directing neural drive to the muscle dur-
ing exercise performance. Theoretically,
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such an approach would increase acti-
vation of the target muscle while dimin-
ishing contribution from secondary
muscle movers. Indeed, research seems
to support this contention.
A number of studies have shown
greater activation of a given muscle
when subjects were instructed to adopt
an internal focus of attention. This has
been most prominently displayed in
the abdominal musculature. Karst and
Willett (3) found that subjects were
able to significantly alter mean electro-
myography (EMG) activity to either
the rectus abdominis or obliques by
consciously focusing on the respective
muscles during performance of the curl
up. Before engaging in exercise, sub-
jects in this study were instructed on
how to visualize either the rectus or
obliques and verbal reinforcement of
these instructions were provided dur-
ing performance. A control condition
involved focusing on the movement
itself without regard to any specific
muscles. These results are consistent
with research showing increased acti-
vation of the transversus abdominis
after instruction to tighten the pelvic
floor muscles (2). Similarly, Bressel
et al. (1) demonstrated that mean and
peak EMG amplitude were significantly
increased in both superficial and deep
abdominal musculature during the
squat when subjects were directed to
“brace yourself as if you were going to
be punched in the stomach.
Findings of heightened EMG activity
from an internal focus have been noted
in other muscles as well. Lewis and
Sahrmann (4) showed that young
women were able to achieve greater
mean EMG activity of the gluteus
maximus and reduced activation of
the hamstrings when cued to contract
the gluteal muscles during perfor-
mance of the prone hip extension
(“Use your gluteal muscles to lift your
leg while keeping your hamstrings
muscles relaxed”). Moreover, the tim-
ing of activation was altered so that
the gluteus maximus was activated sig-
nificantly earlier during movement.
Likewise, research has shown that
intentionally focusing on the target
muscle resulted in higher activation
of the latissimus dorsi, pectoralis major,
biceps brachii, and triceps brachii (5,7–
9). Interestingly, evidence seems to
indicate that the increased activation
does not always coincide with reduc-
tions in the activity of secondary mus-
cle movers (7,8).
Although it remains unclear as to
whether increased muscle activation
translates into greater muscle protein
accretion, emerging research indicates
that this may in fact be the case. In a 2-
part experiment, Wakahara et al. (11)
first investigated acute muscle activation
in 12 untrained men after a single bout
of resistance training for the elbow ex-
tensors through T2-weighted magnetic
resonance imaging. The exercise proto-
col consisted of 5 sets of 8 repetitions of
lying triceps extensions with 90 seconds
rest between sets. Results showed sig-
nificantly greater activation in the prox-
imal and mid-portions of the triceps
brachii compared with the distal aspect.
Another 12 subjects were then recruited
to perform a 3-day-per-week program
consisting of the same routine used in
part 1 of the study. After 12 weeks of
regimented training, increases in muscle
cross-sectional area were found to be
well-correlated to the areas most acti-
vated by the exercise regimen. Follow-
up work by the same laboratory showed
similar results using different triceps bra-
chii exercises (10), which in combina-
tion provide evidence for an association
between activation levels and muscle
growth. It should be noted that these
studies did not attempt to investigate
muscle activation in conjunction with
altered attentional focus, so it is unclear
whether results would translate to the
adoption of an internal focus. Moreover,
the results of these studies are specific to
the triceps brachii and thus cannot nec-
essarily be generalized to other muscles.
Interestingly, the effectiveness of using
an internal focus is reduced when
training at higher loads. Snyder and
Fry (7) found that activation of the pec-
torals was amplified by 22% when
resistance-trained men were provided
with verbal instructions to focus on the
chest muscles during bench press at
50% 1 repetition maximum (1RM).
However, the magnitude of this effect
decreased to 13% when the same in-
structions were provided during per-
formance at 80% 1RM. This may be
a function of needing to exert greater
levels of force when training at heavier
loads, thereby altering one’s ability to
focus on the muscle being worked.
Moreover, in accordance with the size
principle, fewer motor units will be
available for the mind to influence with
heavy loading when compared with
lighter loads. This suggests that adopt-
ing an internal attentional focus with
very heavy loads (above 85–90% of
1RM) is unnecessary because it might
limit force production without enhanc-
ing muscle activation, but more
research is needed in subjects with
varying levels of experience to explore
this hypothesis.
PRACTICAL APPLICATIONS
Attentional f ocus should match the
goal of the task. Competitive sport
athletes should rely heavily on exter-
nal attentional focus in practice and
during games or matches. This in-
cludes powerlifters, weightlifters, or
strongmen seeking to set a 1RM or
to maximize force or tor que produc-
tion; basketball players or track &
field athletes seeking to maximize
jump height or distance; runners or
rowers seeking to improve economy;
and dart throwers, golfers, and pool
players seeking maximum accuracy.
Alternatively, when attempting to
maximize muscle activation, an inter-
nal focus of attention would seem to
be a better choice. Bodybuilders, phy-
sique athletes, and others seeking
maximal hypertrophy will conceiv-
ably benefit by focusing on the target
muscle during an exercise rather than
on the outcome or environment. It is
likely that the molecular signaling for
all 3 primary mechanisms of muscular
hypertrophy, namely mechanical ten-
sion, metabolic stress, and muscle
damage (6), are increased when the
exerciser focuses their attention inter-
nally, which could ultimately result in
greater muscular development for
a given exercise and load. The effects
Evidence-Based Personal Training
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of this strategy seem to be particularly
beneficial when training with rela-
tively light loads.
Conflicts of Interest and Source of Funding:
The authors report no conflicts of interest
and no source of funding.
Brad J. Schoenfeld is an assistant
professor in the exercise science program
at CUNY Lehman College and director
of their human performance laboratory.
Bret Contreras is currently pursuing
his PhD in Sports Science at the Auck-
land University of Technology in Auck-
land, New Zealand.
REFERENCES
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Fontana FE. Effect of instruction, surface
stability, and load intensity on trunk muscle
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e504, 2009.
2. Critchley D. Instructing pelvic floor
contraction facilitates transversus abdominis
thickness increase during low-abdominal
hollowing. Physiother Res Int 7: 65–75,
2002.
3. Karst GM and Willett GM. Effects of
specific exercise instructions on abdominal
muscle activity during trunk curl exercises.
J Orthop Sports Phys Ther 34: 4–12,
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4. Lewis CL and Sahrmann SA. Muscle
activation and movement patterns during
prone hip extension exercise in women.
J Athl Train 44: 238–248, 2009.
5. Marchant DC, Greig M, and Scott C.
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6. Schoenfeld BJ. The mechanisms of muscle
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7. Snyder BJ and Fry WR. Effect of verbal
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8. Snyder BJ and Leech JR. Voluntary increase
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... The trainer said that beginner trainees do not often know the specifc names of the muscles mentioned in videos, hence the opportunity to augment with a visualization. We chose this type of cue because, as mentioned by [61], when the goal is to maximise muscle engagement, internal instructional cues work better than external ones, as they focus on directing the attention towards the body [19]. Additionally, Study 1 showed that during strength training sessions people tended to naturally direct their attention inwards, specifcally towards the muscles they felt active during the exercise, in order to self-evaluate their performance. ...
... As with Study 1, we favoured a combination of deductive and inductive coding; the former due to the theoretical foundation of the study and as a way to simplify the connection of relevant fndings to previous literature, the latter due to the pragmatic nature of the study and the interest in case-related fndings [36]. Theories that informed the top-down approach relate to attention [40], the learning process [31,44], imagery and what enables it [46,64,65], information overload and what causes it [40,68,72], and the reception of the intended meaning of the cues, as discussed in [61,65,68]. As in Study 1, the frst author of this paper led the analysis, all throughout which the codes and constructed themes were frequently discussed, contrasted, and polished with the second author. ...
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The present study investigated whether or not verbal instruction affects the electromyographic (EMG) amplitude of back-squat prime movers. Fifteen resistance-trained men performed back-squat at 50%1-RM and 80%1-RM and received external (EF) or internal focus (IF) on lower-limb posterior muscles. EMG amplitude of gluteus maximus, biceps femoris, gastrocnemius medialis, vastus lateralis and tibialis anterior was recorded during both concentric and eccentric phase. During the concentric phase, the gluteus maximus and biceps femoris EMG amplitude was greater in IF vs EF at 50% [effect size (ES): 0.63(95%CI 0.09/1.17) and 0.49(0.10/0.78) respectively] and 80% [ES: 1.30(0.29/2.21) and 0.59(0.08/1.10)]. The gastrocnemius medialis EMG amplitude was greater in IF vs EF during the eccentric phase at 50% [ES: 0.73(0.13/1.33)] and at 80% [ES: 0.72(0.10/1.34)]. Concomitantly, vastus lateralis EMG amplitude was lower at 50% [ES: −0.71(−1.38/-0.04)] and 80% [ES: −0.68(−1.33/-0.03)]. During the eccentric phase, the tibialis anterior EMG amplitude was greater in IF vs EF at 50% [ES: 0.90(0.12 to 1.68)] and 80% [ES: 0.74(0.13/1.45)]. Irrespective of the load, in the thigh muscles the internal focus promoted a different motor pattern, increasing the hip extensors and reducing the knee extensor excitation during the concentric phase. Concomitantly, both ankle muscles were more excited during the eccentric phase, possibly to increase the anterior-posterior balance control. The internal focus in back-squat seems to have phase-dependent effects, and it is visible at both moderate and high load.
Chapter
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The aim of this study was to assess the effect of verbal instruction, surface stability, and load intensity on trunk muscle activity levels during the free weight squat exercise. Twelve trained males performed a free weight squat under four conditions: (1) standing on stable ground lifting 50% of their 1-repetition maximum (RM), (2) standing on a BOSU balance trainer lifting 50% of their 1-RM, (3) standing on stable ground lifting 75% of their 1-RM, and (4) receiving verbal instructions to activate the trunk muscles followed by lifting 50% of their 1-RM. Surface EMG activity from muscles rectus abdominis (RA), external oblique (EO), transversus abdominis/internal oblique (TA/IO), and erector spinae (ES) were recorded for each condition and normalized for comparisons. Muscles RA, EO, and TA/IO displayed greater peak activity (39-167%) during squats with instructions compared to the other squat conditions (P=0.04-0.007). Peak EMG activity of muscle ES was greater for the 75% 1-RM condition than squats with instructions or lifting 50% of 1-RM (P=0.04-0.02). The results indicate that if the goal is to enhance EMG activity of the abdominal muscles during a multi-joint squat exercise then verbal instructions may be more effective than increasing load intensity or lifting on an unstable surface. However, in light of other research, conscious co-activation of the trunk muscles during the squat exercise may lead to spinal instability and hazardous compression forces in the lumbar spine.
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Low abdominal hollowing in four-point kneeling is used clinically to test and rehabilitate transversus abdominis (TrA) but many people find this exercise difficult to perform. Contracting pelvic floor muscles (PF) during low abdominal hollowing may facilitate contraction of TrA. Thickness increase in the abdominal muscles during low abdominal hollowing has been measured with real-time ultrasound scanning and may indicate muscle contraction. The present study investigated the effect of instructing PF contraction on TrA thickness increase during low abdominal hollowing. Twelve females and eight males with no reported pelvic floor dysfunction or low back pain in the last two years were taught low abdominal hollowing in four-point kneeling. Subjects performed low abdominal hollowing with and without instruction to contract PF in random order. Transversus abdominis, obliquus internus (OI) and obliquus externus (OE) thickness were measured with ultrasound scanning at rest and during both tests. Mean increase in TrA thickness during low abdominal hollowing was 49.71% (SD 26.76%), during low abdominal hollowing with PF it was 65.81% (SD 23.53%). Paired Student's t-tests indicated a significant difference between tests (p = 0.015). There were no significant differences between tests for OE or OI thickness increase. Instructing healthy subjects to co-contract PF results in greater increase in TrA thickness during low abdominal hollowing in four-point kneeling. This may indicate greater contraction of TrA and thus be useful for clinicians training TrA. Further research could investigate the validity of change of thickness as a measure of abdominal muscle contraction, investigate the effect of instructing PF co-contraction on TrA in patients with low back pain and measure PF and TrA activity simultaneously.