Updating the Youth Physical Development Model: 20 key papers and a summary of the evidence
At the 2023 National Strength & Conditioning Association annual meeting in Las Vegas, Dr. Rhodri Lloyd presented The Youth Physical Development Model 2.0: a 10-year Update. The Youth Physical Development Model is a framework originally published in June 2012 for training children and adolescents based on current research and best practice.
In the update, Dr. Lloyd highlighted published research over the last 10 years that either confirmed or provided new insights into training youth. Below are the key papers, many which are systematic reviews and meta analyses, covering all facets of youth athletic development from models (FTEM) to knowledge and practices of practitioners to maturity and injury risk to the effects of training on each of the physical qualities (speed, power, etc.). (Note: although a link is provided, it may or may not lead to either a free or paid link to the full publication.)
20 Key Papers
JP Gulbin, MJ Croser, EJ Morley, JR Weissensteiner. An integrated framework for the optimisation of sport and athlete development: a practitioner approach. J Sports Sci. 2013;31(12):1319-31
K Till, RS Lloyd, S McCormack, G Williams, J Baker, JC Eisenmann. Optimising long-term athletic development: An investigation of practitioners' knowledge, adherence, practices and challenges. PLoS One 2022 Jan 25;17(1):e0262995
JM Radnor, S Moeskops, et al. Developing Athletic Motor Skill Competencies in Youth. Strength and Conditioning Journal, December 2020
M Behringer, A vom Heede, M Matthews, J Mester. Effects of Strength Training on Motor Performance Skills in Children and Adolescents: A Meta-Analysis. Pediatric Exercise Science 23(2):186-206
M Hill, T John, SP Cumming. ‘He’s got growth’: Coaches understanding and management of the growth spurt in male academy football. Volume 18, Issue 1, 24-37, 2022
X Monasterio et al. The burden of injuries according to maturity status and timing: A two-decade study with 110 growth curves in an elite football academy. Eur J Sport Sci 2023 Feb;23(2):267-277.
DM Johnson, SP Cumming, B Bradley & S Williams. The influence of exposure, growth and maturation on injury risk in male academy football players. Journal of Sports Sciences, 2022
C Towlson, J Salter, JD Ade, K Enright , LD Harper , RM Page , JJ Malone. Maturity-associated considerations for training load, injury risk, and physical performance in youth soccer: One size does not fit all. J Sport Health Sci 2021 Jul;10(4):403-412
Lesinski M, Prieske O, Granacher U Effects and dose-response relationships of resistance training on physical performance in youth athletes: a systematic review and meta-analysis. Br J Sports Med. 2016 Jul;50(13):781-95
Lesinski M, Herz M, Schmelcher A, Granacher U. Effects of Resistance Training on Physical Fitness in Healthy Children and Adolescents: An Umbrella Review. Sports Med. 2020 Nov;50(11):1901-1928
Behm DG, Young JD, Whitten JHD, Reid JC, Quigley PJ, Low J, Li Y, Lima CD, Hodgson DD, Chaouachi A, Prieske O, Granacher U. Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis. Front Physiol. 2017 Jun 30;8:423
S Moeskops, JL Oliver, PJ Read, GG Haff, GD Myer, RS Lloyd Effects of a 10-Month Neuromuscular Training Program on Strength, Power, Speed and Vault Performance in Young Female Gymnasts. Medicine and Science in Sports and Exercise Publish Ahead of Print
SL Colyer, R Nagahara, Y Takai, A Salo. The effect of biological maturity status on ground reaction force production during sprinting. Scandinavian Journal of Medicine and Science in Sports 30(8), 2020
RW Meyers, JL Oliver, MG Hughes, JB Cronin, RS Lloyd. Maximal sprint speed in boys of increasing maturity. Pediatr Exerc Sci 2015 Feb;27(1):85-94.
A Sander, M Keiner, K Wirth, D Schmidtbleicher. Influence of a 2-year strength training programme on power performance in elite youth soccer players. Eur J Sport Sci 2013;13(5):445-51.
MJ Cahill, JL Oliver, JB Cronin, KP Clark, MR Cross, RS Lloyd. Sled-Push Load-Velocity Profiling and Implications for Sprint Training Prescription in Young Athletes. J Strength Cond Res 2021 Nov 1;35(11):3084-3089.
A Asadi, H Arazi, R Ramirez-Campillo, J Moran, M Izquierdo. Influence of Maturation Stage on Agility Performance Gains After Plyometric Training: A Systematic Review and Meta-analysis. J Strength Cond Res. 2017 Sep;31(9):2609-2617
O Donti, A Konrad, I Panidi, P Dinas, G Bogdanis. Is There a “Window of Opportunity” for Flexibility Development in Youth? A Systematic Review with Meta-analysis. Sports Medicine - Open, volume 8, Article number: 88 (2022)
JM Radnor, JL Oliver, CM Waugh, GD Myer, and RS Lloyd. The Influence of Maturity Status on Muscle Architecture in School-Aged Boys. Pediatr Exerc Sci. 2020 May 1; 32(2): 89–96.
N Armstrong, JO Welsman. Traditional and New Perspectives on Youth Cardiorespiratory Fitness. Med Sci Sports Exerc 2020 Dec;52(12):2563-2573.
Strength of Evidence
Apologies for just throwing this list of papers at you. Perhaps a future article will be a summary and synthesis of these papers. But for now …dig in … you have some reading to do…. at least the abstract and a few key tables/figures.
At the very least, I can share this slide from Dr. Lloyd’s presentation that provides an indication of the level of evidence from these papers and previous ones on the trainability of physical qualities and athleticism (defined in the NSCA LTAD position statement as the ability to repeatedly perform a range of movements with precision and confidence in a variety of environments, which require competent levels of motor skills, strength, power, speed, agility, balance, coordination, and endurance) in youth.
Overall, it was suggested that the strength of evidence was strongest for strength training and also quite good for speed, power and endurance training and trainability. Although there is some evidence for fundamental or athletic movement skill competency (AMSC) and change of direction/agility, it is either relatively weak, absent or mixed results. And finally, there is either a general lack of studies or evidence for mobility and muscular hypertrophy.
A Final Note
I assume some of you really want to know want changes or modifications Lloyd and Oliver are making to the Youth Physical Development model version 2.0. For now, I am holding off as I do not want to steal their thunder prior to the publication of the paper; however, they did share it publicly at the NSCA Conference ……. so, I have an email in to them asking for permission to share some insights. Stay tuned.