Barbell Medicine - From Bench to Bedside

If early sports specialization is not advantageous in most scenarios, and with an epidemic of inactivity among our youth, we need to find a more effective means of promoting habits for lifelong physical activity. Enter the Long Term Athletic Development Model popularized from a paper by Ford et al in 2011. This framework was originally developed by Istvan Balyi and serves as an evidence-based model to advocate for the best interests of youth athletes. It is not without its critics, and justifiably so. The overall idea is to emphasize training and technique over competition during youth development, which we do support.

The LTAD separates goal-specific development into four stages based on chronological age and developmental maturity. The four stages include

  1. Early childhood
  2. Late childhood
  3. Adolescence
  4. Adulthood.

While the model needs to be viewed as a spectrum based on the needs of the individual child, it does offer useful landmarks and advocacy for focus of training.

Early Childhood (Males aged 6-8, Females aged 6-9)

Competency of technique in this group is low, and neurological adaptations predominate as athletes develop skills over strength. At this stage development should be focused on the “FUNdamentals”.

Structured sport is not warranted at this stage, and training should be “game-oriented” as a means of developing competency with a wide variety of movement patterns. Work should focus on developing coordination, balance, and agility. The authors also advocate for developing muscular endurance, although this can arguably be accomplished through prolonged free play as well.

There is some evidence that prepubertal children have metabolic profiles similar to that of well-trained adult endurance athletes. This supports the axiom that young children are “hard to wear out,” and would make a case for their ability to tolerate an increased volume of play. Play can be goal-directed, such as scoring points or accomplishing a task (e.g., number of times juggling a soccer ball), but should not be directed towards accumulating “wins” over “losses”.

Late Childhood (Males aged 10-13, Females aged 9-11)

This stage is referred to as “Learning to Train”, and this cannot be emphasized enough. Even at this stage, there is still no advocacy for sport-specific training. Unfortunately, in reality this is often the age where specialization begins to occur. It would be considered ludicrous to have a student specialize in mathematics at this point in their life at the expense of reading and science, and the same can be said for specializing in one sport. Children are not usually taught how to train, but rather told what to do. This shifts the focus from development to competition, completely skipping the emphasis of this phase.

The “Learning to Train” phase contains the same balance and muscular endurance training advocacy as the FUNdamentals, but now plyometric and free-weight training have entered the plan. Note that this is not an advocacy for maximum-effort resistance training, but rather a focus on developing technical proficiency. As with the FUNdamentals phase, the more technical movement patterns a young athlete is exposed to and masters, the easier it is for an athlete to subsequently express those traits in future competition. It should be clear that the primary focus of the first two phases are on a high variety of training.

Adolescence (Males 14-18, Females 12-18)

This stage is described as “Training to Train”. This is also the first place where sport-specific training is mentioned, although it should still be performed in conjunction with other training paradigms. The category also has two additional components: “heavy slow resistance” and eccentric training. According to the Long-Term Athletic Development model, the window of optimal trainability, the time when a large portion of athletic development transpires, is from age 11-16, yet in best-case scenarios athletes typically are not introduced to resistance training until at least their freshman year of high school, if at all. This represents three years of missed exposure to interventions that can both increase performance and decrease the risk of injury.

The current best evidence for resistance training recommendations in the youth population come from Lesinski et al which will be discussed later in the prescriptive portion of this text. For the purposes of this section, it is worth noting that females tend to have a larger relative response to training in terms of gaining strength than males.

Female athletes have a 1.6x greater incidence of ACL tears than males, and multiple studies have found decreased strength to be a risk factor for such injuries. O’Kane et al demonstrated in a cohort of female soccer players aged 12-15 that a 1 standard deviation increase in hamstring strength was associated with a 35% reduction in injury risk, while a 1 standard deviation increase in quadriceps strength reduced risk of injury by 30%.

If females derive more benefit from strength training in this age range compared to males, we must question why it is not regularly implemented as a part of youth training programs. This is not to discount the protective effects of strength training on males, however, as Zouita et al found that strength training reduced the risk of injuries 3-fold over the course of one soccer season as well. In addition, the cohort that participated in strength training also demonstrated improvements in speed, cutting, and jumping tasks.

Regarding eccentric training, the point must be made that most resistance training includes an eccentric component. Eccentric training provides a protective effect against muscle strains as seen in studies by Petersen, Goode, and Al Attar specific to the Nordic hamstring curl. Vogt and Hoppeler explored the mechanisms by which this might occur, dichotomizing the function of eccentric contractions into either a “shock absorber” or “elastic spring”. They go on to advocate for the utility of eccentrics in increasing muscle strength and power and optimizing the length-tension relationship. With the protective effect and performance enhancement effects of this training modality, it should likely be an integral part of any training program for athletes in the Training to Train phase.

Adulthood (Males 18+, Females 18+)

The final stage of the Long-Term Athletic Development Model is “Training to Compete”. As this text is primarily focused on the development of youth athletic potential, not much time will be devoted to the exploration of this stage. Ideally, the movement competency in this cohort should be high, but this should still be seen as a framework in which to continue developing new skills. The same core components of heavy resistance, eccentrics, balance, and plyometric training hold, but at this point an athlete is “cleared” to specialize in their sport.

Whereas in the Learning to Train and Training to Train phases the focus was on skill development, the focus now shifts to allow the athlete to express their skills in their desired sport. If that sport is not strength-focused (i.e., sports other than weightlifting and powerlifting), resistance training takes a secondary role – though it should not go away entirely. Given the established effects of resistance training on improving performance and reducing injury risk, it should remain an integral part of training no matter the athlete’s ultimate sport of choice.

In conjunction with the ACSM recommendations for resistance training twice per week, a review by Ciolac demonstrated multiple advantages for the implementation of lifelong strength training.

  • Attenuates loss of strength and muscle mass
  • Improves/reduces loss of bone mineral density
  • Improves weight control/cardiovascular health
  • Reduces risk of falls later in life

While the Long-Term Athletic Development Model represents the “ideal” of capturing individuals at young ages, the heuristic can be applied across the lifespan. In other words, all training should start with the “FUNdamentals” no matter when it begins — even among adults undertaking their first physical pursuits. An activity that is enjoyed is more likely to be continued, and then the parameters for training for the activity can be learned. Once some mastery has been achieved, training can be directed towards maximizing variables related to the sport so that when Training to Compete is reached, the athlete has a broad foundation of skills to express in their chosen sport. As seen in youth sports, early specialization tends to forego developing the breadth of skills necessary to become a “general athlete” first, before becoming a specific type of athlete.

In the context of resistance training, this can be seen as the transition from “beginner” to “advanced” lifters. There is no definitive timeline within which this occurs, and will be unique to every individual. It is also okay for an athlete to remain in the Training to Train phase, as this effectively keeps their training viewed as a process instead of becoming hyper-focused on the specific end-goal of becoming “advanced”.

With all that said, for every great plan or model there is always a “but”, and the long-term athletic development model is no different. Many athletes have violated this rule and went on to achieve high levels of success. We are not arguing that the long-term athletic development model is the absolute way to approach training. For example, there is decent evidence that in order to be a high-level gymnast, specialization needs to occur at a young age. However, the question could be posed as how many second-tier gymnasts could have become elite-level sprinters, soccer players, or weightlifters if exposed to different sports earlier.

About Derek Miles

Derek Miles is a residency trained physical therapist currently working at Stanford Children’s Hospital as the Advanced Clinical Specialist in the rehabilitation department. He worked at the University of Florida prior for 10 years in sports medicine treating a variety of athletic injuries from overuse to post-operative. He is involved in the peer review process for academic journals and has spoken at national level conferences within the physical therapy profession. If not treating patients or in the gym Derek is likely either cooking some form of meat or reading books related to various random topics. He occasionally brews a pretty good American Pale Ale as well.

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