The Effects of Focus Attention Instructions on the Movement Kinetics, Muscle Activation and Performance during Resistance Exercise

Abstract

The aim of this study was to compare kinetics, muscle activation and performance during resistance exercises between internal focus attention instructions, external focus attention instructions and control condition. Thirty (n = 30, mean age = 21.40 ± 0.93 years old) healthy men were recruited as participants and were asked to perform resistance exercises in three conditions; i) internal focus, ii) external focus and iii) control (no focus attention instruction). Participants performed 10RM squat and deadlift assessment in which kinetics, muscle activation and number of repetitions completed were recorded and analyzed during the exercises. Findings of this study revealed that external focus attention instruction produced greater force production and number of repetitions completed while at the same time lower muscle activity compared to the internal focus conditions. To conclude, external focus attention instructions were suggested to be adopted during resistance training due to its effectiveness to make movement more economic while producing greater performance in which will be more advantages for future adaptations.

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The Effects of Focus Attention Instructions on the Movement Kinetics,
Muscle Activation and Performance during Resistance Exercise
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JICETS 2019
Journal of Physics: Conference Series 1529 (2020) 022008
IOP Publishing
doi:10.1088/1742-6596/1529/2/022008
1
The Effects of Focus Attention Instructions on the Movement
Kinetics, Muscle Activation and Performance during
Resistance Exercise
Ali Md Nadzalan1, Jeffrey Low Fook Lee1, Nur Ikhwan Mohamad1, Mohamad
Shahrul Azzfar1, Nor Fazila Abd Malek1 & Ebby Waqqash2
1Faculty of Sports Science and Coaching, Sultan Idris Education University, Perak,
Malaysia
2Centre for Sport & Exercise Sciences, University Malaya, Kuala Lumpur, Malaysia
ali.nadzalan@fsskj.upsi.edu.my
Abstract. The aim of this study was to compare kinetics, muscle activation and performance
during resistance exercises between internal focus attention instructions, external focus
attention instructions and control condition. Thirty (n = 30, mean age = 21.40 ± 0.93 years old)
healthy men were recruited as participants and were asked to perform resistance exercises in
three conditions; i) internal focus, ii) external focus and iii) control (no focus attention
instruction). Participants performed 10RM squat and deadlift assessment in which kinetics,
muscle activation and number of repetitions completed were recorded and analyzed during the
exercises. Findings of this study revealed that external focus attention instruction produced
greater force production and number of repetitions completed while at the same time lower
muscle activity compared to the internal focus conditions. To conclude, external focus
attention instructions were suggested to be adopted during resistance training due to its
effectiveness to make movement more economic while producing greater performance in
which will be more advantages for future adaptations.
1. Introduction
Verbal instruction is one of the teaching approaches used during resistance training session. Using
verbal instructions, instructor (i.e. coaches, personal trainers, and lecturers) can provide information
on what the individuals (i.e. athletes, clients, students) need to do during the resistance training
session/class to enhance their exercise techniques while at the same time to improve their ability in
performing the exercises. An effective verbal instruction is believed to benefit an individual‟s
progression whilst ineffective instructions might possibly impair the learning process that will result in
undesirable outcomes in mastering the exercise techniques.
Wulf [1] found the performance of a task was influenced by the direction of focus attention
during performing the task. Athletes were found not to choose or learn the most effective focus of
attention, instead, they were prone to give their attention based on what the coach instruct [2].
Therefore, it can be concluded here that the verbal instructions provided by the instructor will play a
big role by influencing the individuals‟ direction of focus attention that will next might affect the task
outcome.

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What is actually a focus attention? Focus attention refers to what an individual choose to focus
while executing a task. Based on Makaruk and Porter [3], individuals tend to focus their attention to
three directions; neutral, external or internal. Focusing on the movement effects or environment
specific features is what we termed as external focus. Meanwhile, focusing on own body parts is what
we termed as internal focus attention. On the other hand, neutral focus attention refer to an
unconsciously focus on anything during task/skill execution. Internal focus type of instructions has
been the normal form of instruction utilised by instructors as well as in the literature on physical
conditioning.
The advantages of external focus compared to internal focus has been referred to the constrained
action hypothesis [4, 5]. Based on this hypothesis, individual will perform better if they direct their
focus attention to the movement effect. In contrast, directing focus internally will cause individual to
consciously manage their own movements, in which will make the motor system constraint and next
will unintentionally affected the autonomic control processes.
Despite has been proven in several studies that directing focus externally provide more benefits in
many tasks, there had been also study that demonstrate the effectiveness of internal focus in improving
task performance especially among the novice [6].
Resistance training is a form of training mainly done to improve muscle strength, hypertrophy,
power and muscular endurance. Researches investigating the way to improve resistance training
effectiveness have increased from time to time to various populations [7-12]. Not to be exempt is how
manipulating the focus attention affects the performance in resistance training [13-18]. The knowledge
is needed as resistance training requires the performer to not only have the strength, but the techniques
need to be performed correctly as fault techniques may lead to injuries. Currently, not much study has
been conducted on the biomechanical responses of different focus attention during resistance
exercises.
Questions exist whether are there any differences of kinetics, muscle activation and performance
between internal and external focus attention. The objective of this study was to compare kinetics,
muscle activation and number of repetitions between internal and external focus attention. In addition,
this study also compared the focus attentions instructions with the neutral focus attention (will be
termed as control condition), to look if there is a possibility the performance would be better without
any focus attention instructions. The findings of this study will provide information on the
teaching/coaching methodology to improve individual‟s acute ability in mastering a skill or technique.
2. Methodology
2.1. Participants
This research involved male students (age: 20-25 years old) that enrolled in resistance training class
that volunteered to participate in this study (N = 30). At the time of testing, all participants should be
able to perform all the exercises involved with correct technique. Physical activity readiness
questionnaire (PAR-Q) was used to screen the ability of participation. Each participant should read
and signed an informed consent before data collection. All participants were informed that they were
allowed to withdraw from the study without having to give any justification.
2.2. 1-RM test
One repetition maximum (1RM) test was conducted to obtain the maximum loadings that the
participants can lift during both squat and deadlift exercises. This test is important, as the loadings that
the participants need to lift during the data collection will be 80% from the 1RM value. The
procedures of this 1RM test was based on the guidelines provided by the National Strength and
Conditioning Association (NSCA) [19].

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2.3. Deadlift and Squat Test
Deadlift and squat were performed using a barbell and weight plates. The weights of barbells and
weight plates were measured before data collection. The basic procedures of squat and deadlift
exercise were referred from NSCA manual [20]. All the focus conditions (internal, external and
control) were given common task instruction that is „perform as many repetitions as you can‟. For
deadlift, during both external and internal focus condition, participants were given additional
instructions; i) external focus: “focus your attention on pulling the bar up”, ii) internal focus: “focus
your attention on extending your knees and hips”. Participants were asked to follow the instructions
during performing both tasks. The instructions were given verbally prior the tasks execution. During
performing both tasks, as participants were seem to achieve failure, they were provided with additional
instructions; i) external focus: “pull the bar up”, ii) internal focus: “extend your knees and hips”. This
is a way to ensure that they still giving their focus to the supposed direction.
Squat exercise testing was conducted similar to deadlift. As additional to the general instruction
“perform as many repetitions as you can”, during both internal and external focus condition,
participants were given specific instruction; i) external focus: “Focus on moving and exerting force
through and against the barbell”, ii) internal focus: “Focus on moving and exerting force with your
legs”. As participants were seem to achieved failure, participants were instructed to; i) “push the bar
up” for the external focus and, ii) internal focus: “extend your knees and hips”.
2.4. EMG Collection and Analysis
Wireless Trigno Delsys electromyogram (EMG) was used to record EMG signals from vastus lateralis
and biceps femoris muscles based on the surfaces EMG for non-invasive assessment of muscles
(SENIAM) guidelines [21]. Recorded signals were fully-wave rectified and filtered using a dual-pass,
sixth-order, 10-500 Hz band-pass Butterworth filter, and then a linear envelope were created using a
low-pass, second order Butterworth filter with a cut-off frequency of 6 Hz. EMG signals were
recorded from the start until the end of movement. The EMG value were reported as per maximum
voluntary contraction (MVC).
2.5. Movement Kinetics
During the study, participants performed the squat and deadlift on tri-axial force platform
(BP400600HF-2000, AMTI Inc., USA) (width: 400 mm X length: 600 mm X height: 82.5 mm). Data
sampling rate were set at 200Hz with filter cut-off frequency rate of 10Hz. The kinetics data that were
measured in this study were the concentric ground reaction force that was the average of force
produced between the beginning of concentric phase and the end of concentric force.
2.6 Data Collection
The experiments were held at a well-equipped biomechanics laboratory. To ensure the study outcome
(results) was from the study objectives (comparison of instruction and focus attention), participants
were briefed about the purpose of the study before the data collection. During data collection,
participants were given ten minutes of warm up which consist of light cardiovascular exercise and
lifting 50% of the weight that should be lifted for each exercises. Only full repetitions were counted
for data analysis.
2.7 Statistical Analysis
Physical characteristics and mean score were analysed using descriptive statistics while the
comparison of kinetics, muscle activation and number of repetitions during squat and deadlift between
the focus attention was analysed using repeated measures analysis of variances (ANOVA). Statistical
significance were accepted at an α-level of p ≤ 0.05. All statistical analyses were conducted using
SPSS version 23 (IBM, New York, USA).

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3. Results
3.1 Physical characteristics
Table 1. Physical Characteristics of Participants
Variables
Mean ± SD
Age (years)
21.40 ± 0.93
Body Mass (kg)
69.06 ± 3.34
Height (cm)
172.80 ± 3.50
Squat 1RM (kg)
106.17 ± 13.12
Deadlift 1RM (kg)
122.78 ± 13.33
Table 1 showed the physical characteristics (age, body mass, height, squat 1RM and deadlift 1RM) of
participants involved in this study.
3.2 Muscle activation
The muscle activation data that were measured in this study were the average muscle activity of vastus
lateralis and biceps femoris. Analysis of muscle activation showed significant main effects were found
in: i) vastus lateralis during squat, F(2,58) = 86.37; p = 0.000, ii) biceps femoris during squat, F(2,58)
= 51.25; p = 0.000, iii) vastus lateralis during deadlift, F(2,58) = 95.13; p = 0.000, and iv) biceps
femoris during squat, F(2,58) = 22.91; p = 0.000.
Table 2. EMG data during squat and deadlift
Exercises
Muscles
Internal focus
External focus
Control Condition
Squat
VL (% MVIC)
110.60 ± 8.14bc
101.80 ± 4.06ac
104.80 ± 5.22ab
BF (% MVIC)
67.90 ± 4.03bc
62.90 ± 5.31ac
65.10 ± 4.67ab
Deadlift
VL (% MVIC)
109.50 ± 7.60bc
100.00 ± 4.92ac
105.70 ± 3.37ab
BF (% MVIC)
70.30 ± 5.57bc
67.90 ± 5.18a
68.40 ± 3.35a
a = significantly difference from Internal Focus, p < 0.05
b = significantly difference from External Focus, p < 0.05
c = significantly difference from Control Condition, p < 0.05
Table 2 showed the EMG value during the two exercises’ execution. During squat, results showed
the EMG of vastus lateralis during internal focus was significantly greater compared to external focus
(p = 0.000), and control condition (p = 0.000). External focus EMG was significantly lower compared
to control condition (p = 0.000). EMG of biceps femoris during internal focus was also significantly
greater compared to external focus (p = 0.000) and control condition (p = 0.000). External focus EMG
was significantly lower compared to control condition (p = 0.000).
Similar to squat, during deadlift, results showed the EMG of vastus lateralis during internal focus
was significantly greater compared to external focus (p = 0.000) and control condition (p = 0.000).
External focus EMG was significantly lower compared to control condition (p = 0.000). EMG of
biceps femoris during internal focus was also significantly greater compared to external focus (p =
0.000) and control condition (p = 0.001). External focus was not significantly different compared to
control condition (p = 0.636).

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3.3 Kinetics
The kinetics data that were measured in this study was the concentric ground reaction force (CGRF).
CGRF was defined as the average of force produced between the beginning of concentric phase and
the end of concentric force. Analysis of CGRF showed significant main effects were found in squat,
F(2,58) = 11.36; p = 0.000, and deadlift, F(2,58) = 7.28; p = 0.002.
Table 3. Kinetics data during squat and deadlift
Exercises
Variables
Internal Focus
External Focus
Control Condition
Squat
CGRF (N)
1602.00 ± 48.81bc
1621.00 ± 59.69a
1617.00 ± 54.51a
Deadlift
CGRF (N)
1713.00 ± 49.46bc
1787.50 ± 64.43a
1768.30 ± 49.06a
a = significantly difference from Internal Focus, p < 0.05
b = significantly difference from External Focus, p < 0.05
c = significantly difference from Control Condition, p < 0.05
Table 3 showed the CGRF value during the two exercises protocols. During squat, results showed
the CGRF during internal focus was significantly lower compared to external focus (p = 0.001) and
control condition (p = 0.01). External focus was not found significantly different from control
condition (p = 0.496). Similar to squat, during deadlift, results showed the CGRF during internal focus
was significantly lower compared to external focus (p = 0.004) and control condition (p = 0.009).
External focus was also not found to be significantly different from control condition (p = 0.231).
3.4 Number of repetitions
Number of repetitions was counted as the total number of repetitions that was completed (upward and
downward phase) during the exercises. Analysis showed significant main effects were found in squat,
F(2,58) = 32.59; p = 0.000, and deadlift, F(2,58) = 157.43; p = 0.000.
Table 4. Number of repetitions during squat and deadlift
Exercises
Variables
Internal Focus
External Focus
Control Condition
Squat
Reps
6.50 ± 0.68bc
7.80 ± 0.61ac
7.20 ± 0.41ab
Deadlift
Reps
6.40 ± 0.50bc
8.40 ± 0.50ac
7.20 ± 0.61ab
a = significantly difference from Internal Focus, p < 0.05
b = significantly difference from External Focus, p < 0.05
c = significantly difference from Control Condition, p < 0.05
Table 4 showed the number of repetitions value during the two exercises protocols. During squat,
results showed the repetitions of internal focus was significantly lower compared to external focus (p
= 0.000) and control condition (p = 0.001). Number of repetitions during external focus was
significantly higher compared to control (p = 0.001). Similar to squat, during deadlift, results showed
the repetitions during internal focus was significantly lower compared to external focus (p = 0.000)
and control condition (p = 0.000). Participants were also found to gain significantly greater repetitions
during external focus compared to control conditions (p = 0.000).
4. Discussions
This study was conducted to compare the effects of focus attention on kinetics, muscle activation and
performance during resistance exercises. Thirty trained participants were recruited from a resistance
training class and were needed to perform the exercises in three conditions; i) internal focus, ii)
external focus, and iii) control.

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Average muscle activity of vastus lateralis and biceps femoris were recorded during all focus
conditions. During squat and deadlift, results showed the EMG of vastus lateralis during internal focus
was significantly greater compared to external focus and control condition. Control condition recorded
greater vastus lateralis EMG value compared to external focus. For biceps femoris, during both
exercises, it was also found that the EMG during internal focus was significantly greater compared to
external focus and control condition. External focus EMG was significantly lower during squat but
was found to be no different during deadlift when compared to control condition.
Concentric ground reaction force (CGRF) was recorded as the kinetic data in this study. CGRF
was defined as the average of force produced between the beginning of concentric phase and the end
of concentric force. During both squat and deadlift, results showed the CGRF of both external focus
and control conditions were significantly greater compared to internal focus.
Number of repetitions is counted as the total number of repetitions that was completed (upward
and downward phase) during the exercise. During both squat and deadlift, results showed the external
focus attentions managed to produce more number of repetitions compared to internal focus and
control condition. Control condition on the other hand produces greater number of repetitions
compared to internal focus.
If we based our findings solely on the EMG results, adopting internal focus while doing
resistance exercise was seen to be better as it had been shown that EMG activity during a task was
associated to better long-term muscle size improvement [22]. Thus, for those that aimed for increasing
muscle size that is associated with more muscle strength, adopting internal focus would be more
preferable.
However, hypertrophy and strength adaptations are not solely depend on the EMG activity.
Looking at the results of force production and number of repetitions completed, it can be seen that
despite internal focus attention caused the participant to increase their muscular effort during the
exercise execution, their force production and number of repetitions completed were still lower
compared to the other two focus conditions (i.e. external focus and control conditions). Thus, internal
focus attention is not economically effective in terms of movement production.
Internal focus attention result in decreased capability to produce maximal force, and this is
related to inefficient muscular activation that limits force production. Several previous studies had
suggested that directionally focus internally is associated with an increase in “noise” in the motor
system as quantified through greater muscular activity [23, 24]. Increased noise in the motor system
means that the observed increased muscular activity is not transferred to the movement output.
Looking at the reduced force production, conscious movement control might has interfered with
participant's ability to effectively coordinate and produce maximal force during both squat and deadlift
movements. These results provide additional evidence that focusing on anticipated movement effects
enhances performance compared with internally focusing on the movements being executed [13].
The generally greater EMG activity demonstrate that more energy was used to produce
movement during internal focus compared to external focus condition. Because the movement
outcome (number of repetitions completed) was found to be smaller during internal focus, this showed
that adopting internal focus caused the movement to be less economic.
This study provides converging evidence that movement efficiency or the physical effort exerted
to produce a given outcome varies greatly with an individual’s focus of attention. When an individual
adopts an external focus, movements not only are more effective but also are produced more
economically, with the consequence that the force production and number of repetitions completed
during the resistance exercises are greater [13], the same forces are produced with less muscular
energy [23, 25].
Conclusion
As the conclusion, we can see that adopting external focus attention provide more advantages in
enhancing force production and increase performance during resistance exercise. Although internal
focus attention was found to be not as effective as the external focus, there is a need to further examine

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the greater muscle activities that were produced during the condition that might be more advantages
for hypertrophy. Athletes, physical trainers, coaches and individuals should be aware of the different
effects of different focus attention direction. Based on the findings of this study, it is recommended to
adopt external focus attention in order to increased force production and exercise performance.
However, instructing individuals to direct their focus internally will limit the movement effectiveness
but do result in greater activation of muscles.
Acknowledgement
This study was part of research funded by Universiti Pendidikan Sultan Idris (Code: 2017-0243-107-
01).
Conflict of interest
The authors declare no conflict of interest exist in this study.
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