ArticlePublisher preview available

Importance of mind-muscle connection during progressive resistance training

Authors:
Joaquin Calatayud at University of Valencia
Joaquin Calatayud
Jonas Vinstrup at National Research Centre for the Working Environment
Jonas Vinstrup
Markus Due Jakobsen at National Research Centre for the Working Environment
Markus Due Jakobsen
Emil Sundstrup at National Research Centre for the Working Environment
Emil Sundstrup
Show all 8 authorsHide
Read publisher preview
Download citation
To read the full-text of this research, you can request a copy directly from the authors.

Abstract and Figures

Purpose: This study evaluates whether focusing on using specific muscles during bench press can selectively activate these muscles. Methods: Altogether 18 resistance-trained men participated. Subjects were familiarized with the procedure and performed one-maximum repetition (1RM) test during the first session. In the second session, 3 different bench press conditions were performed with intensities of 20, 40, 50, 60 and 80 % of the pre-determined 1RM: regular bench press, and bench press focusing on selectively using the pectoralis major and triceps brachii, respectively. Surface electromyography (EMG) signals were recorded for the triceps brachii and pectoralis major muscles. Subsequently, peak EMG of the filtered signals were normalized to maximum maximorum EMG of each muscle. Results: In both muscles, focusing on using the respective muscles increased muscle activity at relative loads between 20 and 60 %, but not at 80 % of 1RM. Overall, a threshold between 60 and 80 % rather than a linear decrease in selective activation with increasing intensity appeared to exist. The increased activity did not occur at the expense of decreased activity of the other muscle, e.g. when focusing on activating the triceps muscle the activity of the pectoralis muscle did not decrease. On the contrary, focusing on using the triceps muscle also increased pectoralis EMG at 50 and 60 % of 1RM. Conclusion: Resistance-trained individuals can increase triceps brachii or pectarilis major muscle activity during the bench press when focusing on using the specific muscle at intensities up to 60 % of 1RM. A threshold between 60 and 80 % appeared to exist.
Figures - available from: European Journal of Applied Physiology
This content is subject to copyright. Terms and conditions apply.
A preview of this full-text is provided by Springer Nature.
Learn more
Content available from European Journal of Applied Physiology
This content is subject to copyright. Terms and conditions apply.
1 3
Eur J Appl Physiol (2016) 116:527–533
DOI 10.1007/s00421-015-3305-7
ORIGINAL ARTICLE
Importance of mind‑muscle connection during progressive
resistance training
Joaquin Calatayud1,4 · Jonas Vinstrup1 · Markus Due Jakobsen1,2 · Emil Sundstrup1,2 ·
Mikkel Brandt1,3 · Kenneth Jay1,2,4 · Juan Carlos Colado4 · Lars Louis Andersen1,3
Received: 27 May 2015 / Accepted: 27 November 2015 / Published online: 23 December 2015
© Springer-Verlag Berlin Heidelberg 2015
activity of the other muscle, e.g. when focusing on activating
the triceps muscle the activity of the pectoralis muscle did not
decrease. On the contrary, focusing on using the triceps mus-
cle also increased pectoralis EMG at 50 and 60 % of 1RM.
Conclusion Resistance-trained individuals can increase
triceps brachii or pectarilis major muscle activity during
the bench press when focusing on using the specific muscle
at intensities up to 60 % of 1RM. A threshold between 60
and 80 % appeared to exist.
Keywords Muscle activation · Internal focus · Strength
training · Bodybuilding
Abbreviations
EMG Electromyography
pectoralis Pectoralis major
Triceps Tricepsbrachii
1RM One-maximum repetition
RMS Root-mean-square
Introduction
For years bodybuilders have used the principle of focusing
on contracting specific muscles to enhance muscle size and
increase ‘the pump’. Indeed, the American College of Sports
Medicine considers the technique of voluntarily squeez-
ing the muscles as a way to provide self-resistance during
resistance training (Ratamess 2011). However, scientific lit-
erature evaluating the effectiveness of selectively focusing
on specific muscles during exercise performance is scarce
(Snyder and Fry 2012). Different verbal instructions have
provided greater EMG response during maximal isometric
contractions of both the elbow flexors and leg muscles (Sah-
aly et al. 2003). Instructions to selectively activate specific
Abstract
Purpose This study evaluates whether focusing on using
specific muscles during bench press can selectively activate
these muscles.
Methods Altogether 18 resistance-trained men participated.
Subjects were familiarized with the procedure and performed
one-maximum repetition (1RM) test during the first session.
In the second session, 3 different bench press conditions were
performed with intensities of 20, 40, 50, 60 and 80 % of the
pre-determined 1RM: regular bench press, and bench press
focusing on selectively using the pectoralis major and triceps
brachii, respectively. Surface electromyography (EMG) sig-
nals were recorded for the triceps brachii and pectoralis major
muscles. Subsequently, peak EMG of the filtered signals were
normalized to maximum maximorum EMG of each muscle.
Results In both muscles, focusing on using the respective
muscles increased muscle activity at relative loads between
20 and 60 %, but not at 80 % of 1RM. Overall, a threshold
between 60 and 80 % rather than a linear decrease in selec-
tive activation with increasing intensity appeared to exist. The
increased activity did not occur at the expense of decreased
Communicated by William J. Kraemer.
* Lars Louis Andersen
lla@nrcwe.dk
1 National Research Centre for the Working Environment,
Lersø Parkalle 105, Copenhagen, Denmark
2 Institute of Sports Science and Clinical Biomechanics,
University of Southern Denmark, Odense, Denmark
3 Physical Activity and Human Performance Group, SMI,
Department of Health Science and Technology, Aalborg
University, Aalborg, Denmark
4 Research unit in Sport and Health, Department of Physical
Education and Sports, University of Valencia, Valencia, Spain
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... The bench press exercise is also influenced by both intrinsic motivation, which is focused on the movement itself, and extrinsic motivation, which is focused on the outcome [14][15][16]. Concentration represents a crucial aspect of the training process in sports. It constitutes a significant factor in the development of speed in a variety of sporting activities and is also of importance during resistance training. ...
... The choice of 60% 1RM was selected because it represents a submaximal load, which allows for investigating the effects of muscle activation without reaching the fatigue levels associated with higher intensities. This load is sufficient to elicit significant muscle activation, as observed through EMG while allowing for controlled, repeatable measurements [16,26]. In stage two, the subjects performed 3 sets of 3 repetitions of the bench press with a load of 60% 1RM and internal attention, successively focusing on the pectoral, shoulder, or triceps muscles in each set. ...
... Prior research has shown that it is possible to enhance the activity of the pectoralis major muscle during exercises targeting the chest at loads between 20 and 60% of 1RM, and to augment the activity of the triceps muscle during exercises focusing on the triceps at loads between 20 and 50% 1RM [14,16]. These findings are consistent with our own observations. ...
Effects of Extrinsic and Intrinsic Motivation on Selective Activation of Shoulder Girdle Muscles During the Barbell Bench Press Exercise
Article
Full-text available
  • Nov 2024
Background/Objectives: This study aimed to investigate the effects of intrinsic and extrinsic motivation on selective muscle activation of the shoulder girdle during the barbell bench press. Specifically, this research focused on how attentional focus on individual muscles, such as the anterior deltoid (AD), pectoralis major (PM), and triceps brachii long (TBL), could influence their electromyographic (EMG) activity during the exercise. Methods: Twelve male participants, with at least five years of strength training experience, performed bench press exercises under two conditions: with extrinsic motivation (no specific focus on muscle activity) and with intrinsic motivation (internal focus on specific muscles). Surface electromyography (sEMG) was used to measure muscle activity during three sets of bench presses at 60% of one repetition maximum (1RM). Participants were instructed to focus on the activation of specific muscles in a randomized sequence. Results: The intrinsic motivation condition significantly increased muscle activation compared to extrinsic motivation. Electromyographic activity of the AD, PM, and TBL muscles was notably higher when participants focused their attention on these muscles. AD activation increased from 71.78 ± 11.13%MVC (extrinsic) to 88.03 ± 8.84%MVC (intrinsic) (p = 0.0019), while PM and TBL activation also demonstrated significant increases under intrinsic focus. Conclusions: The study concludes that intrinsic motivation, or an internal focus on specific muscle activation, can significantly enhance EMG activity in target muscles during the bench press exercise. This finding has important implications for resistance training and rehabilitation, where focused muscle activation can be utilized to improve training outcomes and muscle engagement.
View
... A likely explanation for this finding is a differential attentional focus between muscles. Internal concentration on activating a specific muscle can increase its (Calatayud et al., 2016). Participants may have focused more mental effort on their lats or trapezius during lat pull down, inadvertently ramping up activation of the attended synergist to similar levels as the agonist. ...
The Disconnect Between Soccer Players’ Perceived and Actual Electromyographic-Measured Muscle Activation
Article
Full-text available
  • Aug 2024
  • PERCEPT MOTOR SKILL
Understanding muscle activation during exercises is crucial for devising effective training programs. We examined correlations between self-reported and electromyographic (EMG) muscle activity during upper-body exercises performed at loads corresponding to 4-6 repetition maximums (RMs). Thirteen male sub-elite soccer players who had previously engaged in resistance training participated in two testing sessions. In the initial session, the loads corresponding to 4–6 repetitions were determined for six exercises: Lat Pull Down (LPD), Barbell Bent Over Row (BBOR), Dumbbell Row (DR), Barbell Pull Over (BPO), Dumbbell Reverse Fly (DRF), and Dumbbell Concentration Curl (DCC). At post-exercise, participants rated their perceived muscle activation for three targeted muscles in each exercise on a 1–10 point Likert scale (LS). In the subsequent session, we used EMG to measure the activity of eight agonist and synergist muscles during these exercises. We found that one of two synergist muscles consistently demonstrated higher activity levels. Interestingly, we observed no difference in activity between primary and secondary (or synergist) muscles across all exercises. Most importantly, we found no significant correlation between the perceived muscle activation rate and the EMG measured activation level for any exercise. In conclusion, our findings suggest that, despite differential muscle activity during specific exercises, self-reported muscle activation may not accurately correspond to actual muscle activation, as measured via EMG, due to the participants’ poor interoceptive awareness of muscles. These data highlight the potential limitations of relying on perceived muscle activation as a sole gauge of training intensity.
View
... The lack of significant difference in the excitation of these primary muscles between the row exercise conditions might be explained by the exercise intensity. A previous study showed that focusing on specific primary muscles to selectively activate those particular muscles during resistance exercises (i.e., technique defined as mind-muscle connection) was dependent on the exercise intensity; resistance-trained individuals increased the degree of muscle excitation at intensities up to 60% of 1RM (Calatayud et al., 2016). Given the current study used a moderate intensity in both exercise conditions (i.e., 70% of the 10RM), it could demand a similar muscle effort of the medial and lower trapezius regardless of biofeedback. ...
Assessing the Feasibility of EMG Biofeedback to Reduce the Upper Trapezius Muscle Excitation during a Seated Row Exercise, a Non-randomized Comparative Study
Article
Full-text available
  • Aug 2024
  • APPL PSYCHOPHYS BIOF
The upper trapezius muscle is often excessively excited during resistance training exercises, increasing the shoulder’s liability to musculoskeletal disorders of individuals participating in overhead sports or throwing activities. Different approaches have been proposed for reducing the potentially harmful loading of the upper trapezius. None, however, has been devised to deal directly with the main culprit: the muscle excitation. This non-randomized comparative study explores the feasibility of biofeedback based on surface electromyograms (EMGs) in suppressing undue excitation of the upper trapezius during a seated row exercise. Eight male volunteers were instructed to perform the wide-grip seated row exercise without and with the EMG biofeedback of the upper trapezius. Surface EMGs from the three portions of the trapezius and the serratus anterior were sampled with pairs of surface electrodes. A triaxial accelerometer was positioned on the weight stack for the identification of the exercise phase and repetition. This study showed that during the “with biofeedback” condition, the participants were able to activate the upper trapezius and serratus anterior to a lower degree (~ 10%) compared to the “without biofeedback” condition. Future studies should explore if this can lead to greater gains in muscle performance and/or reduce the risk of shoulder injury.
View
... This is the claim that one can increase muscle activation by driving attention to it during an exercise. This sparked empirical research that corroborates the advantages of concentrating on the target muscle during the lift (Calatayud et al., 2016(Calatayud et al., , 2017, but the dualist phrasing might be misleading. Schoenfeld and Contreras (2016), for instance, describe the so-called mind-muscle connection as the 'internally focused strategy [which] involves visualizing the target muscle and consciously directing neural drive to the muscle during exercise performance ' (2016, p. 27). ...
Self-knowledge from resistance training
Article
Full-text available
  • Jul 2024
The problem of self-knowledge has been thoroughly discussed in the context of traditional epistemology. In parallel to that traditional approach, Ecological-Enactive Cognition (EEC) has emerged in the last 30 years as a genuine contender in the cognitive sciences. According to EEC, the unity of analysis of cognitive processes is the dynamics between brain, body and environment. In this paper, I advance an EEC approach to self-knowledge, which immediately suggests that knowing oneself is a matter of knowing what one’s body can do. I then turn to resistance training, particularly weightlifting, and argue that it offers a paradigmatic case of self-knowledge in EEC’s terms. I contend that periodically reaching the point of mechanical failure provides an important insight into self-knowledge. Thus, resistance training allows the trainee to achieve knowledge of themselves in a fundamentally practical manner—and doing so is transformative of the kind of actions they are capable of.
View
... In this context, studies have investigated the effects of many strategies (e.g., nutritional (Spriet & Gibala, 2004), mind-muscle connection (Calatayud et al., 2016), hypnosis (Morton, 2003), and advanced technique (Krzysztofik et al., 2019)) on performance and, consequently, on volume load. However, some strategies present controversial results, while others are costly and may be inaccessible to most RT practitioners (Choi, Kim & Bae, 2022). ...
Effect of warm-up protocols using lower and higher loads on multiple-set back squat volume-load
Article
Full-text available
  • Jul 2024
Background The present study aimed to investigate the effects of post-activation performance enhancement (PAPE) after three warm-up protocols on back squat performance in trained men. Methods Fourteen resistance-trained men performed conditioning activity (CA) with high-load (HL-CA), low-load (LL-CA), or usual specific warm-up as a control (CON). HL-CA consisted of one set of three repetitions with 90% of one repetition maximum (RM); LL-CA consisted of one set of six repetitions with 45% of 1 RM performed at maximal velocity; CON involved eight repetitions with 45% of 1 RM at controlled velocity. The participant’s performance was measured using the total number of repetitions and volume load (reps × load × sets). Results There were no significant differences between warm-up for the total number of repetitions ( p = 0.17) or total volume load ( p = 0.15). There was no difference between conditions for the number of repetitions (main condition effect; p = 0.17); however, participants achieved a significantly higher volume load after HL-PAPE than after CON for the first set ( p = 0.04). Conclusion High or low equated-load CA used as warm-up strategies did not potentiate subsequent performance enhancement in multiple-set back squat exercise performed until muscle failure in comparison with usual warm-up.
View
... Brain and muscle are connected through different mechanisms by the denominated muscle-brain axis (Burtscher et al., 2021;Rai and Demontis, 2022). A growing body of evidence supports that the mindmuscle connection during exercise is essential not only for progressing in the training programs (Calatayud et al., 2016), but also for maximizing the cognitive benefits of physical activity in the brain (Blomstrand et al., 2023). Therefore, scientific evidence conclude that resistance training is essential not only for ensuring a global health of the subject, but also for maximizing mind and brain functioning. ...
A comprehensive study of the academic benefits and practical recommendations to include resistance training programs in institutional education
Article
Full-text available
  • May 2024
The connection between physical activity and cognitive function has become a focus of attention in educational research in recent years. Regular exercise has been shown to have significant positive effects on physical health, but it also appears to have a significant impact on cognitive function and academic performance. Of all the exercise modalities, resistance training has drawn interest for its ability to improve cerebral abilities in addition to physical well-being. However, there is limited available knowledge exploring the relationship between resistance training regimens and academic performance. This narrative review aims to investigate the underlying mechanisms linking resistance training to academic performance. Firstly, we will examine the biological mechanisms and psychosocial links that potentially connect resistance training to academic performance to find and describe the different mechanisms by which resistance training improves academic performance. In the next part of the work, we delve into the existing observational and intervention studies that have explored the relationship between resistance training and academic performance. Lastly, we provide practical recommendations for including resistance training in institutional education settings, emphasizing the need of dispelling myths and addressing barriers to increase participation as well as the relevance of considering key training variables and adaptation of protocols to developmental stages, always guided by a properly trained professional. Overall, the available evidence supports that resistance training provides potential benefits to the academic performance of youth students with many biological and psychosocial factors that explain this relationship. However, most of the studies are observational, and broader interventional studies are needed to understand and maximize the benefits of this type of physical exercise.
View
... reaktive Sprungleistung bei entsprechenden Tests hat. Bekannt ist ebenso[12], dass die Aktivierung der Muskulatur um bis zu 60% zu nimmt, wenn Probanden sich bei Maximalkraftmessungen auf den zu messenden Muskel konzentrieren, wobei die Aktivierung der Agonisten dabei nicht beeinträchtigt wird. Dies muss in der Untersuchung berücksichtigt werden.Kommentiert [ 9]: Das ist irgendwie ein krasser sprung, was hat das mit dem davor zu tun ? ...
Einfluss aktiver und passiver Dehnung auf die Maximalkraftleistung der Schultermuskulatur
Preprint
Full-text available
  • Sep 2023
Um sich auf eine sportliche Leistung, wo Maximal- oder auch Schnellkraft erforderlich ist, vor-zubereiten, wird von Trainern das Dehnen empfohlen. Doch ob dies wirklich dafür sorgt, dass wir eine bessere Leistung abrufen können, sollte mit Hilfe der vorliegenden Studie genauer untersucht werden.
View
... Hence, 54 studies with 6277 participants were included in the final quantitative meta-analysis. Among the final included studies assessing the effects of exercise interventions, 11 studies with 1751 participants analyzed global cognition (Alghadir et al., 2016;Arrieta et al., 2020;Balazova et al., 2021;Carta et al., 2021;Coelho-Junior et al., 2020;Geard et al., 2021;Kamegaya et al., 2014;Muscari et al., 2010;Santos et al., 2020;Calatayud et al., 2015;Zotcheva et al., 2021), 33 studies with 3062 participants analyzed executive function (Arrieta et al., 2020;Kamegaya et al., 2014;Antonio Parraga-Montilla et al., 2021;Brown et al., 2021;van den Berg et al., 2019;Cekanauskaite et al., 2020;Coetsee and Terblanche, 2017;Costigan et al., 2016;Eather et al., 2019;Fallah et al., 2013;Frost et al., 2021;Gothe et al., 2014;Kimura et al., 2010;Klusmann et al., 2010;Akko, 1 et al., 2020), 23 studies with 2515 participants analyzed memory (Arrieta et al., 2020;Coelho-Junior et al., 2020;Santos et al., 2020;Brown et al., 2021;Cekanauskaite et al., 2020;Gothe et al., 2014;Klusmann et al., 2010;Kamijo et al., 2011;Kosmat and Vranic, 2017;Leahy et al., 2020;Liu-Ambrose et al., 2010;Ludyga et al., 2018;Meijer et al., 2020;Moreau et al., 2017;Mortimer et al., 2012;Nouchi et al., 2014;Ruscheweyh et al., 2011;Erickson et al., 2011;Sexton et al., 2020;Taylor-Piliae et al., 2010;Tao et al., 2016;Cassilhas et al., 2007;Latino et al., 2021), 9 studies 1659 participants analyzed attention (Antonio Parraga- Montilla et al., 2021;Brown et al., 2021;van den Berg et al., 2019;Moreau et al., 2017;Latino et al., 2021;Li et al., 2015;Qi et al., 2021;Linde and Alfermann, 2014;Solianik et al., 2021), and 7 studies with 451 participants analyzed information processing (Arrieta et al., 2020;Cekanauskaite et al., 2020;Gothe et al., 2014;Ruscheweyh et al., 2011;Taylor-Piliae et al., 2010;Linde and Alfermann, 2014;Wang et al., 2019). Study characteristics, exercise prescriptions, and cognitive tests of interest are given in Supplement 5. ...
Effects of exercise interventions on cognitive functions in healthy populations: A systematic review and meta-analysis
Article
Full-text available
  • Nov 2023
  • AGEING RES REV
Chronic exercise intervention is a non-pharmacological therapy suggested to improve cognitive function in various populations. However, few meta-analyses have assessed the cognitive benefits associated with all FITT-VP variables (exercise frequency, intensity, bout duration time, type, volume or total intervention length, and progression) in healthy populations by age. Thus, this meta-analysis assessed the effects of each FITT-VP variable on cognitive function in healthy children, adults, and older adults. This study followed PRISMA guidelines. After searching PubMed and the Web of Science, we included 54 randomized controlled trials to examined the effects of FITT-VP variables on five cognitive domains: global cognition, executive function, memory, attention, and information processing. Moderation analyses assessed the effects by age and by each exercise variables. Exercise benefitted overall cognition and all subcognitive domains. Aerobic and resistance exercise showed the greatest benefits on global cognition and executive function respectively, whereas mind-body exercise benefitted memory. Among all populations, older adults showed the greatest benefits of exercise on global cognition, executive function, and memory compared with controls. Additional studies are needed to assess the effects of exercise on attention and information processing. This meta-analysis offers new insights on the relationships between cognition and FITT-VP exercise variables in healthy populations.
View
... Regarding electromyographic assessment, verbal encouragement improves abdominal muscle activation during crunch exercise in healthy individuals (2) . Calatayud et al. report that different verbal stimuli brought about better electromyographic responses during a maximal voluntary isometric contraction (3,4) . However, to date, no studies have been found to verify the influence of verbal encouragement on body stability. ...
The influence of verbal encouragement on corporal stability during the traditional frontal plank exercise in young health adults: a pilot study
Article
Full-text available
  • Mar 2023
Background: It’s known that the frontal plank exercise presents a greater demand of the biomechanics stability and it is largely prescribed and used during the practice by the health professionals, known the verbal encouragement influence on corporal stability through the professional feedback can contribute positively in the clinical, social and scientific field. Objectives: Verify the verbal encouragement influences on corporal stability during the traditional frontal plank exercise in young health adults. Methods: Subjects were selected in an intentional non-probabilistic way, constituting a sample of young male adults, with normal body mass index, moderate to advanced self-reported physical activity level and with, at least, six months of previous resistance training experience. Participants were instructed to perform the traditional frontal plank for 30 seconds keeping all the items in the description of the technique, no command was given besides the following verbal incentives: “Contract, stabilize, force, maintain and force”. After the execution, the professional self-reported his perception of body stability, writing down his answers on the control form. Results: The sample consisted of 10 participants, with a mean age of 30.6 years (±4.03). All male, white and with no history of trauma/injury. For individuals with less than one time of weekly physical exercise, verbal encouragement showed a positive response in the perception of body stability. As for the remainder, who practiced physical exercise with greater recurrence, the evaluator's perception of high stability was given both with and without verbal encouragement. Conclusion: This pilot study showed that in individuals with less time of weekly physical exercise, verbal encouragement showed a positive response in body stability, changing from moderate to high. But, the individuals with more time of practice, the verbal encouragement showed no response in the perception of body stability.
View
... In healthy individual, the internal focus (also called mindmuscle connection) may increase muscle activity, especially at lowmoderate intensities. 46 In addition, focusing on maximal contraction of a muscle group (e.g., internal focus) during strength exercise has been reported to be superior to increase muscle thickness than external focus (or simply moving the load during strength exercise). 47 In contrast, external focus or distraction manoeuvres using dual tasks have been reported to improve muscular endurance. ...
Exercise variables and pain threshold reporting for strength training protocols in people with haemophilia: A systematic review of clinical trials
Article
  • Feb 2023
  • HAEMOPHILIA
Introduction: Although strength exercise is often prescribed for people with haemophilia (PWH), it remains unknown how exercise variables and pain thresholds are used to prescribe strength training in PWH. Aim: To analyse how strength exercise variables and pain thresholds have been used to prescribe strength training in PWH. Methods: A systematic search was conducted in PubMed, Embase, Web of Science, CENTRAL and CINAHL databases from inception to 7 September 2022. Studies whose intervention included strengthening training in adults with haemophilia were included. Two independent reviewers were involved in study selection, data extraction and risk of bias assessment. Results: Eighteen studies were included. The least reported variables among the studies were: prophylactic factor coverage (11.1%), pain threshold/tolerability (5.6%), intensity (50%), total or partial range of motion (27.8%), time under tension (27.8%), attentional focus modality (0%), therapist experience in haemophilia (33.3%) and adherence assessment (50%). In contrast, weekly frequency (94.4%), duration (weeks) (100%), number of sets/repetitions (88.9%), repetitions to failure/not to failure (77.8%), types of contraction (77.8%), rest duration (55.6%), progression (55.6%), supervision (77.8%), exercise equipment (72.2%) and adverse event record (77.8%) had a higher percentage of reported (>50% of studies). Conclusion: Future research on strength training for PWH should improve information on pain threshold and other important variables such as prophylactic factor coverage, intensity, range of motion, time under tension, attentional focus modality, therapist experience in haemophilia and adherence assessment. This could improve clinical practice and comparison of different protocols.
View
Muscle activity during leg strengthening exercise using free weights and elastic resistance: Effects of ballistic vs controlled contractions
Article
Full-text available
  • Dec 2012
The present study's aim was to evaluate muscle activity during leg exercises using elastic vs. isoinertial resistance at different exertion and loading levels, respectively. Twenty-four women and eighteen men aged 26-67years volunteered to participate in the experiment. Electromyographic (EMG) activity was recorded in nine muscles during a standardized forward lunge movement performed with dumbbells and elastic bands during (1) ballistic vs. controlled exertion, and (2) at low, medium and high loads (33%, 66% and 100% of 10 RM, respectively). The recorded EMG signals were normalized to MVC EMG. Knee joint angle was measured using electronic inclinometers. The following results were obtained. Loading intensity affected EMG amplitude in the order: low<medium<high loads (p<.001). Ballistic contractions always produced greater EMG activity than slow controlled contractions, and for most muscles ballistic contractions with medium load showed similar EMG amplitude as controlled contractions with high load. At flexed knee joint positions with elastic resistance, quadriceps and gluteus EMG amplitude during medium-load ballistic contractions exceeded that recorded during high-load controlled contractions. Quadriceps and gluteus EMG amplitude increased at flexed knee positions. In contrast, hamstrings EMG amplitude remained constant throughout ROM during dumbbell lunge, but increased at more extended knee joint positions during lunges using elastic resistance. Based on these results, it can be concluded that lunges performed using medium-load ballistic muscle contractions may induce similar or even higher leg muscle activity than lunges using high-load slow-speed contractions. Consequently, lunges using elastic resistance appear to be equally effective in inducing high leg muscle activity as traditional lunges using isoinertial resistance.
View
The Learning Advantages of an External Focus of Attention in Golf
Article
Full-text available
  • Feb 1999
This study examined whether the learning advantages of an external focus of attention relative to an internal focus, as demonstrated by Wulf, Hööß, and Prinz (1998), would also be found for a sport skill under field-like conditions. Participants (9 women, 13 men; age range: 21–29 years) without experience in golf were required to practice pitch shots. The practice phase consisted of 80 practice trials. One group was instructed to focus on the arm swing (internal focus), whereas another group was instructed to focus on the club swing (external focus). One day after practice, a retention test of 30 trials without instructions was performed. The external-focus condition was more effective for performance during both practice and retention.
View
Attentional Focusing Instructions Influence Force Production and Muscular Activity During Isokinetic Elbow Flexions
Article
Full-text available
  • Oct 2009
  • J STRENGTH COND RES
Appropriate verbal instruction is critical to effective guidance of movements. Internal (movement focus) and external (outcome focus) attentional focusing instructions have been shown to influence movement kinetics and muscular activity; this study investigated their effects during a force production task. Twenty-five participants (mean age of 22.72 +/- 1.88 years) completed 10 repetitions of single-arm elbow flexions on an isokinetic dynamometer while electromyographical activity of the biceps brachii and net joint elbow flexor torque were measured. Three trials were completed: a control trial to attain maximum voluntary contraction (MVC) data, followed by counterbalanced trials internal and external attentional focus conditions. The external focus exhibited a significantly (p < 0.05) higher peak net joint torque (102.10 +/- 2.42%MVC) than the internal condition (95.33 +/- 2.08%MVC) and also a greater integral of the torque-time curve (99.90 +/- 2.91%MVC) than the internal condition (93.80 +/- 2.71%MVC). In addition, the external focus resulted in lower peak electromyography (134.43 +/- 16.83%MVC) response when compared with the internal focus condition (155.23 +/- 22.54%MVC) as well as lower mean integrated electromyography (127.55 +/- 12.24%MVC) than the internal condition (154.99 +/- 19.44%MVC). Results indicate that an external attentional focus results in significantly greater force production and lower muscular activity during isokinetic elbow flexions when compared with an internal focus. When instructing clients during maximal force production tasks, practitioners should tailor their instructions to emphasize an external focus of attention. Specifically, attention should be directed onto the movement of the object being moved and away from the specific bodily movements involved in the action.
View
ACSM's foundations of strength training and conditioning
Book
  • Nov 2011
Developed by the American College of Sports Medicine, this text offers a comprehensive introduction to the basics of strength training and conditioning based on the latest research findings. ACSM's Foundations of Strength Training and Conditioning is divided into four parts: Foundations, Physiological Responses and Adaptations, Strength Training and Conditioning Program Design, and Assessment. The text focuses on practical applications, enabling students to develop, implement, and assess the results of training programs that are designed to optimize strength, power, and athletic performance. Moreover, the text's clear, straightforward writing style makes it easy to grasp new concepts. © 2012 by American College of Sports Medicine. All rights reserved.
View
View
Speed dependant influence of attentional focusing instructions on force production and muscular activity during isokinetic elbow flexions
Article
  • Feb 2014
  • HUM MOVEMENT SCI
This experiment assessed the influence of internal (movement) or external (outcome) attentional focusing instructions on force production and muscular activity at different movement speeds. Twenty five participants completed 10 reps of single arm elbow flexions on an isokinetic dynamometer at speeds of 60°, 180° and 300° s−1 under three conditions (control trial, followed by counterbalanced internal and external focus trials). EMG activity of the biceps brachii and net joint elbow flexor torque were measured. An external focus was associated with significantly lower EMG at all speeds when compared to an internal focus. However, an external focus resulted in greater torque production only at 60° s−1 when compared to an internal focus. These findings suggest that movement speed may influence the efficacy of different attentional focusing instructions, with implications for the instruction of movements in sport, exercise and rehabilitation settings.
View
Morphological and Neurological Contributions to Increased Strength
Article
  • Feb 2007
High-resistance strength training (HRST) is one of the most widely practiced forms of physical activity, which is used to enhance athletic performance, augment musculo-skeletal health and alter body aesthetics. Chronic exposure to this type of activity produces marked increases in muscular strength, which are attributed to a range of neurological and morphological adaptations. This review assesses the evidence for these adaptations, their interplay and contribution to enhanced strength and the methodologies employed. The primary morphological adaptations involve an increase in the cross-sectional area of the whole muscle and individual muscle fibres, which is due to an increase in myofibrillar size and number. Satellite cells are activated in the very early stages of training; their proliferation and later fusion with existing fibres appears to be intimately involved in the hypertrophy response. Other possible morphological adaptations include hyperplasia, changes in fibre type, muscle architecture, myofilament density and the structure of connective tissue and tendons. Indirect evidence for neurological adaptations, which encompasses learning and coordination, comes from the specificity of the training adaptation, transfer of unilateral training to the contralateral limb and imagined contractions. The apparent rise in whole-muscle specific tension has been primarily used as evidence for neurological adaptations; however, morphological factors (e.g. preferential hypertrophy of type 2 fibres, increased angle of fibre pennation, increase in radiological density) are also likely to contribute to this phenomenon. Changes in inter-muscular coordination appear critical. Adaptations in agonist muscle activation, as assessed by electromyography, tetanic stimulation and the twitch interpolation technique, suggest small, but significant increases. Enhanced firing frequency and spinal reflexes most likely explain this improvement, although there is contrary evidence suggesting no change in cortical or corticospinal excitability. The gains in strength with HRST are undoubtedly due to a wide combination of neurological and morphological factors. Whilst the neurological factors may make their greatest contribution during the early stages of a training programme, hypertrophic processes also commence at the onset of training.
View
Influence of proprioceptive feedback on the firing rate and recruitment of motoneurons
Article
We investigated the relationships of the firing rate and maximal recruitment threshold of motoneurons recorded during isometric contraction with the number of spindles in individual muscles. At force levels above 10% of maximal voluntary contraction, the firing rate was inversely related to the number of spindles in a muscle, with the slope of the relationship increasing with force. The maximal recruitment threshold of motor units increased linearly with the number of spindles in the muscle. Thus, muscles with a greater number of spindles had lower firing rates and a greater maximal recruitment threshold. These findings may be explained by a mechanical interaction between muscle fibres and adjacent spindles. During low-level (0% to 10%) voluntary contractions, muscle fibres of recruited motor units produce force twitches that activate nearby spindles to respond with an immediate excitatory feedback that reaches maximal level. As the force increases further, the twitches overlap and tend towards tetanization, the muscle fibres shorten, the spindles slacken, their excitatory firings decrease, and the net excitation to the homonymous motoneurons decreases. Motoneurons of muscles with greater number of spindles receive a greater decrease in excitation which reduces their firing rates, increases their maximal recruitment threshold, and changes the motoneuron recruitment distribution.
View
Effect of Verbal Instruction on Muscle Activity During the Bench Press Exercise
Article
  • Nov 2011
  • J STRENGTH COND RES
Recent research suggests that humans have some ability to selectively activate or relax some muscles during isometric or dynamic muscle actions without changing posture or position. This study sought to reveal whether trained athletes could isolate either the pectoral or triceps muscles, respectively, at different intensities when given verbal technique instruction. Eleven male Division III football players performed 3 sets of bench press at 50% 1-repetition max (1RM) and 80% 1RM while electromyographic (EMG) activity was recorded from the pectoralis major (PM), anterior deltoid (AD), and triceps brachii (TB). In the first set, the subjects performed the exercise without instruction. In the second set, the subjects were given verbal instructions to use only chest muscles. In the third set, the subjects were instructed to use only triceps muscles. Mean normalized root mean square EMG activity was calculated during 3 repetitions in each condition. Repeated-measures analysis of variance was used to detect differences from the preinstruction condition, with significance set to p ≤ 0.017 as indicated by a Bonferroni correction for multiple comparisons. During the 50% max lift with verbal instructions to focus on chest muscles, PM EMG activity increased by 22% over preinstruction activity (p = 0.005), whereas AD and TB activities were statistically unchanged. When the subjects were instructed to focus on only the triceps muscles, PM returned to baseline activity, whereas TB activity was increased by 26% (p = 0.005). When the lift was increased to 80% max, PM and AD activities were both increased with verbal instructions to use only chest muscles. The TB activity was unchanged during the 80% lifts, regardless of instructions. In conclusion, it is found that verbal technique instruction is effective in shifting muscle activity during a basic lift, but it may be less effective at higher intensities.
View
Voluntary Increase in Latissimus Dorsi Muscle Activity During the Lat Pull-Down Following Expert Instruction
Article
  • Oct 2009
  • J STRENGTH COND RES
It has been observed anecdotally that while performing the multijoint lat pull-down exercise, novice strength trainers often rely on the elbow flexors to complete the movement rather than fully utilizing the relevant back muscles such as the latissimus dorsi (LD) and teres major (TM). The primary aim of the study was to determine whether specific technique instruction could result in a voluntary increase in LD and TM electromyographic (EMG) activity with a concurrent decrease in the activity of the biceps brachii (BB) during the front wide-grip lat pull-down exercise. Eight women with little or no background in strength training were asked to perform lat pull-down exercise with only basic instruction, performing 2 sets of 3 repetitions at 30% max. After a brief rest, subjects then performed the same 2 sets of 3 repetitions following verbal technique instruction on how to emphasize the latissimus while de-emphasizing the biceps. EMG activity of the LD, TM, and BB were recorded, converted to root mean square, and normalized to the maximum isometric EMG (NrmsEMG). A significant increase was seen in Nrms EMG in the LD (p = 0.005) from the average of preinstruction NrmsEMG to the average of postinstruction NrmsEMG. No significant differences were observed between pre- and postinstruction muscle activity in the BB or TM. The results show that untrained individuals can voluntarily increase the activity of a specified muscle group during the performance of a multijoint resistance exercise, but the increase probably does not represent "isolation" of the muscle group through voluntary reduction of activity in complementary agonist muscles.
View