Building athletes for life: why strength, mobility and stretching matter - and why the earlier you start, the better
In our last post, we looked at Osgood-Schlatter and Sever's disease, two common growth-related conditions that sideline young athletes during exactly the years when they're most passionate about their sport. Both conditions are fundamentally overload injuries: the demand placed on developing tissues exceeds the body's current capacity to handle it.
But here's the question worth asking: what if we could build that capacity proactively, before the injury happens?
That's what this post is about. The evidence for strength training and mobility work as injury prevention tools, particularly in young athletes, is compelling. And the habits built during adolescence don't just protect young people now. They carry forward into adulthood, laying the foundation for a lifetime of active, healthy movement.
The injury problem in youth sport
Sport is enormously valuable for young people physically, socially and psychologically. But it also carries a real injury burden, and one that is increasing as training loads intensify and year-round sport becomes the norm.
Many of the overuse injuries we see in adults, knee tendinopathies, hip pain, shoulder problems, stress fractures, have their roots in movement habits and physical deficiencies that were never addressed during the formative sporting years. A young athlete who develops poor squatting mechanics and weak glutes at 13 and is never taught otherwise will likely still squat that way at 33, by which point the cumulative damage to their knees may be well underway.
The good news is that the evidence clearly shows these injuries are not inevitable. A recent meta-analysis of children and adolescent athletes indicates that resistance training reduces sports-related injuries, both overuse and acute, by up to 66%. That is a remarkable number, and it speaks to how much potential there is in getting this right early.
Why strength training is so important for young athletes
There is a persistent and outdated myth that strength training is unsafe for young people that it will stunt growth or damage developing bones. The evidence comprehensively disagrees.
There is clear evidence that resistance training can be a worthwhile and beneficial activity for children and adolescents. Supervised resistance training protocols are relatively safe for youth, with injury rates that are low and injuries that tend to be minor and self-resolving.
Resistance training among youth aged 6 to 18 years elicits improvements in muscular strength, power, running speed, endurance, dynamic balance, flexibility and general motor performance. These gains make young athletes more resistant to sports-related injuries.
The key word throughout the research is supervised. Strength training with good technique, age-appropriate loading and qualified oversight is safe and highly beneficial. It's unsupervised, ego-driven loading, the kind we discussed in our gym shoulder and anterior knee pain posts, that creates problems.
For young athletes specifically, strength work builds the muscular foundation that their sport demands. A footballer needs hip and knee strength to change direction safely under fatigue. A netballer needs calf and ankle strength to absorb landing forces. A swimmer needs shoulder girdle and rotator cuff strength to maintain stroke mechanics across a long session. Without that foundation, the joints and tendons absorb forces that the muscles should be managing — which is precisely how overuse injuries develop.
Training intervention programmes have been shown to reduce the risk of lower extremity knee injuries in young athletes by 25%. Combined with the broader injury reduction effects of a well-designed programme, the case for including strength work as a core part of any young athlete's routine is clear.
Why mobility and stretching matter - but in the right way
Mobility and flexibility are often spoken about interchangeably, but they are distinct and both important.
Flexibility refers to the ability of a muscle to lengthen. Mobility refers to the ability to move through a full range of motion with control, stability and coordination. When restrictions exist because of lack of flexibility or mobility, movement is less efficient and the risk of injury increases. Many soft tissue injuries occur during the eccentric phase of a movement, when muscles and tendons are under load and on stretch. If a joint lacks flexibility, maximal lengthening of the surrounding muscles occurs earlier in the movement, and under load this can lead to injury.
For young athletes, tight hip flexors from excessive sitting, limited ankle mobility from poor footwear choices, and restricted thoracic spine mobility from screen time are extremely common, and all of them directly compromise sport performance and injury risk.
The timing of stretching matters enormously. Dynamic stretching is the preferred warm-up mode before training and competition, as it increases core and muscle temperature, muscle firing rates and flexibility while reducing injury risk before explosive movement. Static stretching, on the other hand, is most effective during cool-down to relax the muscles and support recovery.
This is something many young athletes and their coaches get backwards, long static stretching before sport, and nothing afterwards. Teaching the right approach early means athletes carry those habits into their adult sporting life.
The habits you build young, you keep for life
This is arguably the most important point in this entire post, and one that doesn't get said nearly often enough.
The movement habits, body awareness and physical literacy that young athletes develop during their formative years, the way they squat, land, decelerate, hinge and brace, become deeply ingrained patterns that persist into adulthood. Professionals in all areas of youth sports believe strength and conditioning programmes benefit young people by solidifying long-term athletic development and improving bone and muscle health, hormone regulation, body composition, body awareness, movement control and longevity in sport through injury prevention.
A 14-year-old who is taught to squat well, warm up properly, stretch after training, manage their load intelligently and understand how their body responds to exercise is building a toolkit they will use for the rest of their life. A 14-year-old who is never taught these things, who trains exclusively sport-specific skills without any physical development work, is building a set of compensations and deficiencies that will accumulate silently until their body eventually protests loudly.
We see this pattern play out repeatedly in clinical practice. The adult who presents with chronic knee pain, recurring hamstring strains or persistent shoulder problems frequently has a history of intensive youth sport with no structured physical preparation. The tissue damage may only become symptomatic in adulthood, but its roots are much earlier.
Getting the foundations right in youth isn't just about playing sport now without pain. It's an investment in decades of healthy, active life.
The role of exercise physiology at Colab Health Group
This is where an accredited exercise physiologist becomes an invaluable member of a young athlete's support team.
An EP at Colab Health Group doesn't just prescribe exercises they assess the whole athlete. That means evaluating movement quality, strength asymmetries, flexibility restrictions, training load across all sports, recovery habits and physical development stage. From that assessment they design a programme that specifically addresses the young athlete's individual needs and sport demands.
For a young athlete currently managing Osgood-Schlatter or Sever's disease, an EP works alongside the physiotherapist to ensure training continues safely while the growth-related condition is managed, keeping the athlete active, building their physical base and preventing deconditioning during what can otherwise feel like a frustrating period of reduced sport participation.
For a healthy young athlete without a current injury, an EP can design a structured strength and conditioning programme to proactively reduce their injury risk, improve their athletic performance and teach them the movement skills and training habits they'll carry forward for life.
The safety and efficacy of youth strength and conditioning programmes depend on proper instruction, coaching and supervision. Types of training include bodyweight strengthening, resistance bands, medicine balls and weights, agility, plyometrics and cardiovascular exercise, all preceded by a proper warm-up combining static stretching, self-myofascial release, dynamic warm-ups and sport-specific movements. An EP provides exactly this: qualified, evidence-based, age-appropriate programming with the supervision and coaching that makes it both safe and effective.
What this looks like in practice
A typical EP programme for a young athlete at Colab Health Group might include:
A structured dynamic warm-up routine that the young athlete can replicate independently before every training session and game. Sport-specific strength work targeting the muscle groups most loaded in their sport, hip and knee strength for field sports, shoulder and core for swimming and racquet sports, posterior chain for running athletes. Mobility work addressing common restrictions for their sport and age group. Plyometric and landing mechanics training to reduce ACL and ankle injury risk. Cool-down and static stretching protocols to support recovery. Load management education, helping the young athlete (and their parents and coaches) understand how to balance training, competition and recovery across a season.
When to see us
The best time to start is before there's a problem. If your child is:
Actively competing in one or more sports
Beginning to increase their training load or move into representative competition
Recovering from a growth-related condition like Osgood-Schlatter or Sever's
Experiencing recurring muscle soreness, tightness or minor niggles
About to begin a gym-based strength programme for the first time
...an assessment with our exercise physiologist is a worthwhile investment. The foundations built now will pay dividends across a lifetime of sport and physical activity.
References
Liu H, Liu X, Yin L. Effects of multicomponent exercise injury prevention programs on adolescent team athletes: a systematic review and meta-analysis. Frontiers in Pediatrics. 2026. https://doi.org/10.3389/fped.2025.1561993
Faigenbaum AD, Kraemer WJ, Blimkie CJR, et al. Youth resistance training: updated position statement paper from the National Strength and Conditioning Association. Journal of Strength and Conditioning Research. 2009;23(5 Suppl):S60–S79.
Myer GD, Faigenbaum AD, Ford KR, Best TM, Bergeron MF, Hewett TE. When to initiate integrative neuromuscular training to reduce sports-related injuries and enhance health in youth? Current Sports Medicine Reports. 2011;10(3):157–166.
Jayanthi N, Post EG, Laury TC, Fabricant PD. Health consequences of youth sport specialization. Journal of Athletic Training. 2019;54(10):1040–1049.
Robles-Palazón FJ, et al. Effectiveness of exercise-based interventions for reducing injury incidence in youth team-sport players: a systematic review and network meta-analysis. Annals of Medicine. 2024. https://doi.org/10.1080/07853890.2024.2408457
Lloyd RS, Oliver JL, Faigenbaum AD, Howard R, Croix MBAS, Williams CA, et al. Resistance training in youth: laying the foundation for injury prevention and physical literacy. Strength and Conditioning Journal. 2015;37(1). PMC5582694.
Cheng J, Stokes M, DiLeo A, Gerhart HD, Cole BJ, Yanke AB. Strength and conditioning in the young athlete for long-term athletic development. Current Reviews in Musculoskeletal Medicine. 2024. PMC11299322.
Page P. Current concepts in muscle stretching for exercise and rehabilitation. International Journal of Sports Physical Therapy. 2012;7(1):109–119.
Human Kinetics. Flexibility training to decrease injury risk. us.humankinetics.com. 2024.
Li Y, et al. The effects of training intervention on the prevention of knee joint injuries: a systematic review and meta-analysis. PMC. 2025. PMC11891182.