November 28, 2020

By: ATH Director of Human Performance Frank Bourgeois, PhD




For many decades, it has been common practice to expose youth to various programs that aim to develop physical ability and athletic competency. Recently, however, there has been a shift to avoid training youth as miniature adults, but rather construct training regiments that accommodate individuals according to their maturation stage. Existing research demonstrates that this approach first identifies where an individual is relative to their growth spurt – known as Peak Height Velocity (PHV) – and classifies them as pre-, mid- and post-PHV for before, during and after their growth spurt, respectively. Next, certain types of training maybe systematically introduced to enhance physical abilities that underpin athletic performance. In doing so, practitioners capitalize on favorable neuromuscular and anatomical changes individuals experience as they mature, while reducing the likelihood of injury. With the improvement of functional movement competency being ubiquitous throughout the Youth Physical Development model, respective windows of opportunity are used to guide the incorporation of strength, speed, hypertrophy and sport-specific skills training to encourage long-term development.




The development of athletic qualities among youth is certainly not a novel concept, particularly in North America. Annually there are significant resources devoted to enhancing physical abilities believed to be critical to maximizing both short- and long-term athletic success. In 2009, a leading authority in sport and exercise science in the United States – the National Strength and Conditioning Association – updated its position regarding resistance training of youth, emphasizing children should not be trained like miniature adults, but most likely require an approach that best accommodates their level of physical growth and development (1). Its position corroborated the Long-term Athletic Development model previously recommended by Canadian sports scientist, and sparked international interest in investigating and identifying critical windows of opportunity during the physical development of youth as they progress in maturation. Of note, there has been a shift from categorizing and training individuals according to chronological age, to categorizing and training individuals according to the biological age. 


In this article the most forefront training approach – The Youth Physical Development model (2)– will be discussed to give insight into the selection and scheduling of different training modes based on an individual’s biological age or maturation stage. These maturation stages are based on identifying where an individual is in their ‘growth spurt’, termed peak height velocity (PHV), with stages classified as pre-, mid- and post-PHV for individuals before, during and after their most rapid stage of growth, respectively. 




Fundamental movement and sport-specific skills


The ability to generate correct movement patterns is widely considered a hallmark component of athletic success irrespective of age. This is primarily due to efficient movement being critical to executing technical and tactical tasks in competition. A key window of opportunity to begin developing fundamental movement is in pre-PHV, or before the ‘growth spurt’. 


During this maturation stage, individuals experience rapid nervous system development with appreciable development to the muscular system occurring as well (3). It is here where gross motor skills that underpin athletic performance may be established to prepare the individuals for progression to more complex motor skills in the mid-PHV stage, and finally to more complex sports-specific movement in the post-PHV stage. 


It should be noted, due to the fundamental importance of gross motor skills, it is recommended performance in basic movement tasks be assessed because neuromuscular and anatomical changes will occur as the individual matures. Therefore, regularly scheduled assessment of gross movement competency will ensure areas of deficiency are addressed to increase the likelihood of efficient movement, and thus physical ability.  


Strength and hypertrophy 


Historically, there have been safety concerns regarding exposing pre- and mid-PHV individuals to resistance training. Trepidation of noxious damage to tendons, bone, growth plates and muscles to 'growing' individuals has misguided parents and guardians to largely avoid resistance training in children. However, it is now widely accepted that youth can safely participate in and benefit from a supervised systematic resistance training program (4, 5, 6). The two overarching components of resistance training that will be discussed are strength training, which primarily seeks to enhance tissue integrity and force capabilities; and hypertrophy training, which primarily seeks to enhance anatomical features of muscle, such as cross-sectional area.


Similar to fundamental movement, pre-PHV is the initial window of opportunity to improve strength capacity in athletic development. This is primarily due to the rapid development of the central and peripheral nervous systems experienced during this maturation stage. Such development is advantageous in improving relative strength because neural input is a significant contributor to force output (7). As the individual progresses to mid- and post-PHV, hypertrophy training may be systematically introduced to complement strength training to begin taking advantage of increased levels of circulating hormones associated with the growth spurt.   




Concerning power training – which consists of more rapid force absorption and exertion – some training focus should be allotted during pre-PHV to aid in developing force absorption capabilities, and begin to address technical aspects of rapid multi-joint movements, such as a vertical and horizontal jump. However, the primary window of opportunity is at the onset of mid-PHV. This being primarily due to the more rapid development of neuromuscular characteristics experienced during pubescence (8).




Speed is widely concerned to be a critical factor in athletic success. Analogous to most of the aforementioned physical qualities, improvement in sprint-oriented tasks – that is, straight-line and multidirectional sprints – is trainable throughout all maturation stages. While it is documented pre-PHV individuals can experience speed enhancement due to greater neural demands associated with jump and sprint training (9), this maturational stage should also be used to begin training technical factors, such as postures, positions and movement sequencing, associated with straight-line and multidirectional sprints. Specific to multidirectional speed, there should also be a systematic balance between training pre-planned tasks that are executed in static environments (e.g. the L-run) and training tasks that place a demand on cognitive function via a dynamic environment that requires greater perceptual and decision-making processes.




The Youth Physical Development model provides a logical and empirically-based approach to achieve realistic training-induced responses for both male and female individuals as they progress through the maturation stages of pre-, mid- and post-PHV. Pivotal to this model is the advocation of introducing functional movement, strength and speed training during the pre-PHV stage to take advantage of the neural and technical demands of each training mode. As individuals progress to mid-PHV, training sports-specific skills, hypertrophy and power may be  incorporated to compliment advancements in movement, strength and speed training to take advantage of the increase in hormone secretion associated with this maturation stage. Once post-PHV has been reached, more complex training methods may be incorporated with confidence in an attempt to maximize athletic development. 




  1. Faigenbaum AD, Kraemer WJ, Blimkie CJ et al. Youth resistance training: updated position statement paper from the National Strength and Conditioning Association. Journal of Strength and Conditioning Research. 23:S60-79,2009.
  2. Lloyd RS, Oliver JL. The youth physical development model: a new approach to long-term athletic development. Strength and Conditioning Journal. 34(3):61-72,2012.
  3. Borms J. The child and exercise: an overview. Journal of Sports Science. 4:4-20,1986.
  4. Chiodera P, Volta E, Gobbi G et al. Specifically designed physical exercise programs improve children's motor abilities. Scandinavian Journal of Medicine and Science and Sports. 18:179-87,2008.
  5. Lloyd RS, Oliver JL, Hughes MG et al. Effects of 4-weeks plyometric training on reactive strength index and leg stiffness in male youths. Journal of Strength and Conditioning Research. 26(10):2812-19,2012.
  6. McGuigan MR, Tatasciore M, Newton RU et al. Eight weeks of resistance training can significantly alter body composition in children who are overweight or obese. Journal of Strength and Conditioning Research. 23:80-5,2009.
  7. Sale DG. Neural adaptation to resistance training. Medicine and Science in Sports and Exercise. 20(5):S135-45,1988.
  8. Beunen GP, Malina RM. Growth and physical performance relative to the timing of the adolescent spurt. Exercise and Sport Sciences Reviews. 16:503-40,1988.
  9. Rumpf MC, Cronin JB, Oliver JL et al. Effect of different training methods on running sprint times in male youth. Pediatric Exercise Science. 24:170-186,2012.

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