Genes with Jeb: Advancements in Exercise with Omics Technology

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Jeb Struder is currently a doctoral student at the University of Connecticut studying  the cellular and molecular responses of skeletal muscle to exercise and stressful environments. He also serves as the Director of Research for the Korey Stringer Institute


Twitter:  @j_struder



Transcriptomic Profiling of Skeletal Muscle Adaptations to Exercise and Inactivity


Learning Through Observation

Recently, I sat in a lecture on observational learning, which was supplemented by a another lecture on self-regulated learning. Surprisingly, there hasn’t been a handful of research regarding observational learning as it pertains to motor skill learning and performance. I wanted to dig in a little deeper and share with you a quick overview.

It all started with Giacomo Rizzolatti (Discovery of mirror neurons) when his work with canonical neurons and the neural representation of motor movements in monkeys led to the discovery of mirror neurons. The basic idea was that canonical neurons are transforming affordances of objects. Meaning, it’s enough to observe a door knob for you know how to grasp it (in this case, it was a peanut). But it was soon realized that in some cases, just showing, wasn’t enough. In order for the monkey’s neurons to fire, the object had to be grasped. This led to the idea of congruence. The monkey needed to be able to also grasp the object in order for its mirror neurons to fire when a person grasped the same object.

Mirror neurons are neurons with motor processes that fire not only during action execution, but also when observing someone else performing the same or similar action. Likewise, observation of movements also activates the same areas that are used to preform those movements. In a review by Iacoboni (2009), it was concluded that;


  • Mirror neurons fire during observation, but not during observation of pantomime. Meaning, they are goal oriented.
  • Mirror neurons fire when say graspable objects are occluded by a screen.
  • Mirror neurons discharge in response to the intention or goal rather than action itself.
  • Mirror neurons are Multimodal; they can discharge to sound.
  • Mirror neurons are related to motor experience with a given action.

As a function of experience, Orgs et al., (2008) found that event related desynchronization in alpha and beta frequency of experts was modulated by an individual’s expertise with a certain movement style. So yes, the more you see it, the better. Further, the phenomena of observational learning has played in imperative role in motor learning albeit the research evidence is not immense. Coaches and clinicians are constantly using demonstration as a tool to enhance the rate of learning or optimizing current performance.

Observational Learning

Horn et al., (2007) found that novices in a model group, where they were observed a video model, learned a maximum velocity back-handed reverse baseball pitch to a greater extent than those who practiced based on just verbal instruction/guidance. What was really interesting was that the model group individuals showed immediate change in their intra-limb coordination, mimicking closely to the model’s relative motion pattern. In fact, ball speed was also improved. As a result, in early acquisition (i.e., rehabilitation) a model may represent an efficient and stable behavioral change that can enhance the rate of learning. In other words, a model can also be used as a constraint that allows salient information to be perceived. Watching an expert is typically the approach coaches adhere to when teaching a motor skill. Sometimes, its even the coach itself, whom they think is the expert. Clark & Ste-Marie (2007) wanted to see what would happen if the self was used as a model intervention. They used children who were learning how to swim. One group either saw a videotape of their own performance (self observation) where as the other group saw an edited video of their own best performance (self modeling). The self modelling group performed better. They concluded that implementing self-modelling interventions is a useful strategy to optimize learning.

Practicing in Groups

 Dyad training is considered effective and efficient. In fact, most teams practice in dyads. In slight contrast, rehab settings most often times don’t. Shea and colleagues (1999) compared three groups (individual, dyad alternate, and dyad control) using a balance task. In the dyad alternate group the order looked something like this; partner 1 went while partner 2 observed and on the next trial, partner 2 went and partner 1 observed. In the dyad control group, partner 1 went, performed all trials while partner 2 observed, and then they switched. They found that the dyad alternate group did best in retention whereas the dyad control group came in second, still doing better than the individual group. It was concluded that dyad training is beneficial due to observational learning, increased motivation (support/competition) and sharing or receiving feedback. Thus, practice should include observation and dialog between learners. Applying this type of framework is something coaches should strive to do. Lastly, Granados & Wulf (2007) found that observation and dialogue are also beneficial to motor learning in dyad practice, though these results should be extended to larger groups.


 The aforementioned literature goes in line with the soft versus hard assembled mechanisms debate. A hard assembled mechanism is independent of the immediate context, but is revealed across multiple contexts. For example, my rule about a “swish” in basketball remains whether on a basketball court, shooting a paper ball into a garbage can, etc. In contrast, a soft assembled mechanism is constrained within context. As mentioned by Kloos & Van Orden (2009), this can be the kinematics of a limb in a particular action. Like Bernstein (1967) alludes to, repetition of this soft assembly will reveal assemblies that have unique kinematics, albeit not context free. I bring this up because motor learning is typically associated with prescriptive, direct learning approaches that enable such “soft assemblies” to be formed, providing only temporary solutions. Here, it is demonstrated that observational learning is a powerful tool that enables coaches and clinicians to constrain information without using a prescriptive approach. As a result, you no longer have the formation of “soft assemblies,” but more efficient and stable behavioral changes.



  • Coaches should integrate observational learning during practice.
  • A self-modeled approach, where good performances are seen and referenced improve motor performance and learning.
  • When practicing in dyads, allow for dialogue to occur and strategies to be verbalized.
  • Particularly in rehabilitation settings, observational learning is powerful for the efficient and effective behavioral changes that allow for retention and transfer.



 Clark, S. E., & Ste-Marie, D. M. (2007). The impact of self-as-a-model interventions on children’s self-regulation of learning and swimming performance. Journal of sports sciences25(5), 577-586

Granados, C., & Wulf, G. (2007). Enhancing motor learning through dyad practice: contributions of observation and dialogue. Research quarterly for exercise and sport78(3), 197-203.

Horn, R. R., Williams, A. M., Hayes, S. J., Hodges, N. J., & Scott, M. A. (2007). Demonstration as a rate enhancer to changes in coordination during early skill acquisition. Journal of Sports Sciences25(5), 599-614.

Iacoboni, M. (2009). Imitation, empathy, and mirror neurons. Annual review of psychology60, 653-670.

Kloos, H., & Van Orden, G. C. (2009). Soft-assembled mechanisms for the unified theory. Toward a unified theory of development: Connectionism and dynamic systems theory re-considered, 253-267.

 Orgs, G., Dombrowski, J. H., Heil, M., & Jansen‐Osmann, P. (2008). Expertise in dance modulates alpha/beta event‐related desynchronization during action observation. European Journal of Neuroscience27(12), 3380-3384.

 Shea, C. H., Wulf, G., & Whltacre, C. (1999). Enhancing training efficiency and effectiveness through the use of dyad training. Journal of motor behavior31(2), 119-125.



Rethinking Feedback: Creating More Effective and Efficient Training Environments – AVCA 2019

I had a wonderful time at the American Volleyball Coaches Association (AVCA) convention presenting alongside Coach Speraw on the role of feedback in the sport of volleyball. Sad I couldn’t be there the whole time, but glad I was able to make the long drive despite a cancelled flight…with no sleep! In hindsight, there are some things I wished we hit on, and perhaps some things I hoped to make clearer. I humbly apologize for any mistakes made when relaying the information related to the research literature. It was actually my first time talking to coaches (and a lot of them!), not so much researchers or those in the field of psychology/motor learning/biomechanics. I learned so much and so I thank each and every one who attended. I do wish you took at least one tangible concept that you can apply to your practice. There was a great mix of coaches who represented different levels of volleyball in attendance (club, college, and national levels!). It goes to show the power of growth our sport has been able launch in the United States. Seeing such a diverse crowd was a reminder as to why bridging this gap between research and practice is so important. A big thank you to Coach Speraw and USA Volleyball who allowed me to be part of this. As mentioned, him, Dr. Becker, and myself have had some conversations surrounding this topic and wanted to share some of what we are brainstorming. I wanted to make some of the slides available and also wanted to address questions alongside further explanation. You’ll see I’ve put together a conglomerate of many different research ideas and papers onto this one document. My hope is that after you read this, you have more questions.  As always, feel free to reach out to me with any questions, comments, or concerns. One thing for certain is that I also have many questions for coaches too! Let’s learn together. Here is the link:

Rethinking Feedback


With Love,

Harjiv Singh

Rethinking ACL Rehabilitation and Prevention

Hi all! Below is a preliminary list of ACL literature connecting motor learning to prevention and rehabilitation. By no means is this an exhaustive live. It’ll be updated. PDF’s are available! Just email one of us.

ACL injury prevention, more effective with a different way of motor learning?

Optimization of the anterior cruciate ligament injury prevention paradigm: novel feedback techniques to enhance motor learning and reduce injury risk.

Principles of Motor Learning to Support Neuroplasticity After ACL Injury: Implications for Optimizing Performance and Reducing Risk of Second ACL Injury

Novel methods of instruction in ACL injury prevention programs, a systematic review

Click to access Novel-methods-of-instruction-in-ACL-injury-prevention-programs-a-systematic-review.pdf

Mechanisms Underlying ACL Injury-Prevention
Training: The Brain-Behavior Relationship

The effects of attentional focus on jump performance and knee joint kinematics in patients after ACL reconstruction

Click to access GokelerPhysTherSport2015.pdf

Immersive virtual reality improves movement patterns in patients after ACL reconstruction: implications for enhanced criteria- based return-to-sport rehabilitation

Click to access 544a22e90cf2f6388084f5a5.pdf

Using principles of motor learning to enhance ACL injury prevention programs

Training for Prevention of ACL Injury: Incorporation of Progressive Landing Skill Challenges Into a Program

Click to access Training_for_Prevention_of_ACL_Injury__.10.pdf

Feedback Techniques to Target Functional Deficits Following Anterior Cruciate Ligament Reconstruction: Implications for Motor Control and Reduction of Second Injury Risk


Neuroplasticity Following Anterior Cruciate Ligament Injury: A Framework for Visual-Motor Training Approaches in Rehabilitation

Review of the Afferent Neural System of the Knee and Its Contribution to Motor Learning

Altered electrocortical brain activity after ACL reconstruction during force control

Neuroplasticity Associated With Anterior Cruciate Ligament Reconstruction

Does brain functional connectivity contribute to musculoskeletal injury? A preliminary prospective analysis of a neural biomarker of ACL injury risk

Click to access diekfuss_brain_connectivity_injuries.pdf

A novel approach to enhance ACL injury prevention programs

Is neuroplasticity in the central nervous system the missing link to our understanding of chronic musculoskeletal disorders?

Recommended Reading: Ecological Psychology and Motor Learning

Here are recent (2019) recommended readings as they pertain to some of the factors surrounding the ecological approach to motor learning. Likewise, we’ve developed a basic schematic to help your basic understanding of how psychology has evolved. By no means is this a complete picture.

  1. The History and Philosophy of Ecological Psychology
  2. Ecological cognition : expert decision-making behaviour in sport
  3. Ecological Representations
  4. Perceiving Metaphors: An Approach From Developmental Ecological Psychology




Strategies to Reduce ACL Injury Risk in Youth Athletes – Part 2 (Strength Training)

In part 1 of our series on reducing ACL injuries in adolescent athletes, I discussed the mechanisms leading to the injury itself and warm-up strategies to reduce injury risk (

Part 2 will discuss strength training, including:

– what does the research state on strength training and injury?

– what are some fundamental resistance exercises that an adolescent athlete should be introduced to and perform?

– what is a proper way to regress / progress a strength exercise?

Let’s dive in…

Strength Training

 In my opinion, the introduction of sports into a youth’s life should coincide with an introduction to strength training. You may be thinking, “my (insert age) child should be lifting weights? Isn’t that dangerous?” It’s actually quite the opposite. Under proper supervision, a strength training program may offer an adolescent athlete a multitude of physical, emotional, and psychological benefits (Faigenbaum, 2009). Overall, it appears that 8-12 weeks of resistance training can improve overall strength by 30-50% in youth athletes (Dehab & McCambridge, 2009).

(Faigenbaum, 2009)

For the sake of scope, let’s focus our attention on the effects of strength training for reducing injury risk in this population. So what does the research tell us? One of the earliest studies completed on strength training and injury rate was by Hejna (1982). High school athletes were divided into three groups: weight training during the pre-season and in-season, weight training year-round, and a control, non-strength training group. The researchers found that athletes who participated in weight training had an injury rate of 26.2%, while the control group’s injury rate was 72.4%. If an injury were to occur, the control group took approximately 2.4 times longer to rehabilitate from injury compared to their strength training counterparts.

After 8 weeks of resistance and plyometric training, 27 female high school athletes demonstrated improvements in neuromuscular and biomechanical movement qualities that suggest these athletes were at less risk for ACL injury (Lephart, 2005). Specifically, the athletes demonstrated increases in quadriceps strength during dynamometer testing and greater muscular activity in the gluteus medius bilateral vertical jump (Lephart, 2005). Additionally, athletes displayed increased hip and knee flexion during the jump-landing maneuver (Lephart, 2005). In a meta-analysis by Sugimoto (2015), across 14 reviewed studies, strength interventions reduced the risk of ACL injury by 68% in youth female athletes. A larger meta-analysis by Lauersen, Bertelsen, & Andersen (2014) provide additional evidence for strength training to reduce injury risk, as “strength training reduced sports injuries to less than 1/3 and overuse injuries could be almost halved”. So the question becomes, what specific strength exercises should youth athletes complete? From multiple investigations, it appears that even the addition of bodyweight exercises can have a significant impact on injury risk. Keep in mind that bodyweight exercises are a form of resistance training! Walden (2012) incorporated unilateral/bilateral squats, glute bridges, lunges, planks, and jump-landings, resulting in a 64% reduction in ACL injury. Similar exercises were incorporated into a warm-up for female youth soccer athletes, resulting in a 77% reduction in knee injury rate (Kiani, 2010).

(Walden, 2012)

The basis of strength training for adolescent athletes is mastering basic movement patterns that are transferable to a multitude of more complex resistance exercises. We want to ensure that our athletes are not adding strength to dysfunction, which can lead to many future issues. A requisite for every adolescent (and any athlete for that matter) is demonstrating proper form in the following “fundamental” exercises: hip-hinge / Romanian deadlift, body-weight squat, forward/backward lunge, push-up, pull-up/inverted row, and over-head press.

In addition to form, proper exercise progression is a must for younger athletes, as these motor patterns are very much malleable and quickly receptive to adaptation, for better or worse. Here’s an example of a squat exercise progression that I have found quite successful with youth athletes:

1) hip-hinge

2) body-weight squat (may add box behind athlete)

3) squat with a PVC pipe

4) goblet and/or resistance band squat

5) unloaded barbell back/front squat

6) loaded barbell back/front squat

Again, I cannot stress the following enough: do not add strength to dysfunction. If your athlete cannot adequately perform a barbell squat, there is no benefit to adding further load to this movement. Similar progressions can be made for any upper or lower body compound exercise. Sometimes that will include the use of resistance bands or partners (e.g. assisted pull-ups), TRX equipment (single-leg squats, inverted rows), or the training center itself (wall assisted push-ups). To reap the most benefits of strength training program, youth athletes should be participating in a strength program at twice per week at a minimum (Behm, 2008). It is beyond the scope of this post to discuss the physiological adaptations to resistance training, but athletes need to be consistent in their training to obtain build resiliency within the musculoskeletal system. Loading the system in a sensible and progressive manner throughout our young athletes’ sporting careers will provide the opportunity for maximal performance, but more importantly, will keep them on the field.

If you’re looking to dive deeper into the literature regarding strength training for adolescent athletes, I highly recommend these position papers:

National Strength and Conditioning Association –

Canadian Society for Exercise Physiology –

UK Strength and Conditioning Association –


Behm, D. G., Faigenbaum, A. D., Falk, B., & Klentrou, P. (2008). Canadian Society for Exercise Physiology position paper: resistance training in children and adolescents. Applied Physiology, Nutrition, and Metabolism33(3), 547-561.

Dahab, K. S., & McCambridge, T. M. (2009). Strength training in children and adolescents: raising the bar for young athletes?. Sports Health1(3), 223-226.

Faigenbaum, A. D., Kraemer, W. J., Blimkie, C. J., Jeffreys, I., Micheli, L. J., Nitka, M., & Rowland, T. W. (2009). Youth Resistance Training: Updated Position Statement Paper From the National Strength and Conditioning Association. Journal of Strength and Conditioning Research,23(Supplement 5), S60-S79. doi:10.1519/jsc.0b013e31819df407

Hejna, W. F., Rosenberg, A., Buturusis, D. J., & Krieger, A. (1982). The Prevention of Sports Injuries in High School Students Through Strength Training. National Strength Coaches Association Journal,4(1), 28-31. doi:10.1519/0199-610x(1982);2

Kiani, A. (2010). Prevention of Soccer-Related Knee Injuries in Teenaged Girls. Archives of Internal Medicine,170(1), 43-49. doi:10.1001/archinternmed.2009.289

Lauersen, J. B., Bertelsen, D. M., & Andersen, L. B. (2014). The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. British Journal of Sports Medicine48(11), 871-877.

Lephart, S. M., Abt, J. P., Ferris, C. M., Sell, T. C., Nagai, T., Myers, J. B., & Irrgang, J. J. (2005). Neuromuscular and biomechanical characteristic changes in high school athletes: a plyometric versus basic resistance program. British Journal of Sports Medicine39(12), 932-938.

Sugimoto, D., Myer, G. D., Foss, K. D., & Hewett, T. E. (2015). Specific exercise effects of preventive neuromuscular training intervention on anterior cruciate ligament injury risk reduction in young females: Meta-analysis and subgroup analysis. British Journal of Sports Medicine,49(5), 282-289. doi:10.1136/bjsports-2014-093461

Walden, M., Atroshi, I., Magnusson, H., Wagner, P., & Hagglund, M. (2012). Prevention of acute knee injuries in adolescent female football players: Cluster randomised controlled trial. BMJ,May 3(344). doi:10.1136/bmj.e3042