How Do We Ensure Our “Mini Adults” Become Elite Adult Competitors?

Lebron James weighed in on the “Load Management” debate this week – however, rather than focusing his attention on NBA players he has discussed the issue from the perspective of an adolescent athlete. In an article by Marcel Mutoni on the “SLAM” website (, James highlighted the intense physical demands placed on young basketball players competing in Amateur Athletic Union (AAU) basketball tournaments, involving multiple games in a day. But given the increasing obesity epidemic facing the western world, and that physical activity levels are at an all-time low, wouldn’t there be a benefit in adolescents playing more? They’re young – surely they can handle it! Right? Tim Gabbett and the team at Gabbett Performance Solutions dig a little further in this article.

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Figure 1. Lebron James weighs in on the load management discussion. Is load management needed in adolescent athletes?


Where Might the Problem Start?

In an attempt to understand the positive and negative effects of training, we recently systematically reviewed the relationship between workloads and physical performance, injury and illness in adolescent athletes [5]. Of the 23 articles that met our selection criteria, only 4 were associated with negative outcomes. Of these:

  • Greater training duration and poorer stress/recovery scores were associated with greater illness [2];
  • Rapid increases in training load were associated with increases in injury rates [4];
  • Greater increases in training load lead to more groin pain [8];
  • 1.0-3.8% of athletes (1) were both highly stressed and poorly recovered, (2) had high training volumes and were poorly recovered, or (3) had high training volumes, were highly stressed and poorly recovered [6].

There were some key findings from this review. First, negative responses to training do happen, but not often (at least not commonly researched and reported). Second, clearly there is a point where training (and other physical activity) changes from offering benefits to becoming a problem. But where does the problem start?

Is the Competition:Training Ratio the Problem?

A recent study compared the training and game volumes of adolescent collision sport athletes who sustained and injury or remained injury-free [7]. No differences were found between injured (246 min/week) and uninjured (243 min/week) players for training volume per week. However, injured players had a 32% greater game volume than uninjured players (110 vs. 83 min/week). Training volume was not a significant predictor of injury risk, but every ~1 hour increase in game volume, increased injury risk by 41%. Appropriate training load prepares athletes for competition demands, but when competition demands exceed this physical preparation, injury risk is increased.


Figure 2. A schematic illustration of an “ideal” competition:training ratio, where a large base of physical preparation prepares athletes for competition demands.


Adolescents Are Not Mini-Adults!

When we consider training, one factor (among many), that we need to consider is age. When prescribing training load, practitioners often refer to age-appropriate training. But what does this mean? We can think of age in three ways:


Figure 3. The three ways of thinking about an athlete’s age.

Age is a moderator of the training load—injury relationship. In other words, depending on their Chronological Age, athletes have a better (or worse) ability to tolerate training load. However, the moderating effect of age is not limited to chronological age. Training Age (analogous to training history) and Biological Age can also impact an athlete’s ability to tolerate training load. Peak Height Velocity (where maximum rate of growth occurs) is commonly associated with increased injury risk. A recent study investigated anthropometric measures and growth as risk factors for overuse and acute injuries injuries in youth soccer players [9]. In the younger group (10-12 years), the risk of overuse injuries was associated with an increase in leg length over the season and risk of acute injuries with relatively younger chronological age. In contrast, in the older players (13-15 years), greater leg length was associated with an increased risk of overuse injuries, while greater body mass and a lower growth rate was associated with an increased risk of acute injuries. In another study, van der Sluis et al [10] examined the relationship between adolescent growth spurts and overuse injury. Later maturing players had a higher incidence of overuse injury than their earlier maturing counterparts both in the year before Peak Height Velocity and the year of Peak Height Velocity. The authors concluded that players were especially susceptible to injury between 13.5 and 14.5 years of age.

Figure 4. Two players with the same chronological age but vastly different biological age.


Common recommendations for training adolescent athletes include (1) monitoring age-specific anthropometric and growth-related risk factors, and (2) minimizing abrupt changes in training load during these growth spurts.


Finally, others have compared the performance changes in response to a conditioning program in adolescent (16.9 years) and adult (25.5 years) athletes [3]. Despite having lower training loads, the adolescent athletes exhibited greater improvements in maximal aerobic power and muscular power. These results demonstrate that adolescent and adult athletes adapt differently to a given training stimulus and that training programs should be modified to accommodate differences in training age. Importantly, adolescent athletes do not need excessive training loads to elicit positive training adaptations.


Is There a Solution to the “Over-Playing” Problem?

If the demands on adolescent athletes are increasing, what are some simple recommendations to give our adolescent athletes an opportunity of reaching high performance and enjoying a life-long involvement in sport and physical activity?

  1. The formative years offer an opportunity for young athletes to learn how to train. This includes the discipline of performing consistent training, and also the discipline of preparing for consistent training. Developing good training and recovery habits, including regular sleep patterns, hydration and nutrition strategies, and recovery processes are as an important as the training itself.
  2. Where possible, delay sport specialization until late adolescence. Athletes who sample a variety of sports have a lower risk of injuries, stress, and burnout and a greater chance of accomplishing athletic goals [1].
  3. Except in rare occasions where athletes may peak early (e.g. gymnastics, swimming), there is no such thing as an elite 13-year old! Encourage your adolescents to enjoy sport – and to compete, but also listen to their views about their athletic pursuits. In this respect, we should probably listen to Lebron James: “I’m very conscious of my own child, because that’s all I can control. If my child says he’s sore or he’s tired, he’s not playing!”




  1. Brenner JS. Sports Specialization and Intensive Training in Young Athletes. Pediatrics. 2016 Sep;138(3). pii: e20162148.
  2. Brink MS, Visscher C, Coutts AJ, Lemmink KA. Changes in perceived stress and recovery in overreached young elite soccer players. Scand J Med Sci Sports. 2012 Apr;22(2):285-92.
  3. Gabbett TJ. Performance changes following a field conditioning program in junior and senior rugby league players. J Strength Cond Res. 2006 Feb;20(1):215-21.
  4. Gabbett TJ. Physiological and anthropometric characteristics of junior rugby league players over a competitive season. J Strength Cond Res. 2005 Nov;19(4):764-71.
  5. Gabbett TJ, Whyte DG, Hartwig TB, Wescombe H, Naughton GA. The relationship between workloads, physical performance, injury and illness in adolescent male football players. Sports Med. 2014 Jul;44(7):989-1003.
  6. Hartwig TB, Naughton G, Searl J. Load, stress, and recovery in adolescent rugby union players during a competitive season. J Sports Sci. 2009 Aug;27(10):1087-94.
  7. Hartwig TB, Gabbett TJ, Naughton G, Duncan C, Harries S, Perry N. Training and match volume and injury in adolescents playing multiple contact team sports: A prospective cohort study. Scand J Med Sci Sports. 2019 Mar;29(3):469-475.
  8. Lovell G, Galloway H, Hopkins W, Harvey A. Osteitis pubis and assessment of bone marrow edema at the pubic symphysis with MRI in an elite junior male soccer squad. Clin J Sport Med. 2006 Mar;16(2):117-22.
  9. Rommers N, Rössler R, Goossens L, Vaeyens R, Lenoir M, Witvrouw E, D’Hondt E. Risk of acute and overuse injuries in youth elite soccer players: Body size and growth matter. J Sci Med Sport. 2019 Oct 10. pii: S1440-2440(19)30355-X. doi: 10.1016/j.jsams.2019.10.001.
  10. van der Sluis A, Elferink-Gemser MT, Brink MS, Visscher C. Importance of peak height velocity timing in terms of injuries in talented soccer players. Int J SportsMed. 2015 Apr;36(4):327-32.