In recent years, strength training has taken on an increasingly central role in promoting youth physical activity and well-being. Previously, it was often regarded primarily as a form of exercise for adults, but research has shown that it is also safe and beneficial for young people when carried out correctly and under proper supervision. During adolescence, the development of muscles, bones, and physical capacity forms the foundation for future health and functional ability. (Beam, Fakhoury & Myers 2017.)

From a physiotherapy perspective, it is important to examine how strength training affects the physical functioning of young people, as it can help prevent musculoskeletal problems, improve performance, and enhance self-confidence. This article is part of a series produced within the course Professional in Physiotherapy, which is included in the physiotherapy degree programme. The article was created as part of the evidence-based physiotherapy section of the course. In small groups, students practice elements of a systematic literature review, including systematic information retrieval, critical appraisal using the PEDro scale tool, and writing up the results in the form of a scientific article.

The aim of this mini review was to examine the physical benefits of strength training for adolescents. Our research question was: What are the benefits of resistance training on physical functioning in young people?

Methods

This blog article is based on a mini literature review conducted by physiotherapy students at Savonia University of Applied Sciences, in which the results of three randomized controlled trials (RCTs) were evaluated. In this work we used PubMed database to search studies about the benefits of resistance training in youth. We also practiced using the PEDro scale as an assessment tool.

The research question was structured using the PICO framework, which is a method used to formulate focused clinical or research questions. PICO stands for Population, Intervention, Comparison, and Outcome. In this study, the population consisted of adolescents aged 12–18 years. The intervention involved resistance or strength training, while the comparison group did not participate in any resistance training. The outcomes focused on physical measures, including muscle strength, muscular fitness, body composition, and functional capacity.

We selected studies with a randomized controlled trial (RCT) design that involved healthy adolescents and reported physical outcomes. The literature search was conducted in PubMed using search terms such as adolescents, resistance training, and randomized controlled trial. The inclusion criteria required participants to be adolescents aged 10–18 years, with interventions that included resistance training, which could be combined with aerobic exercise as long as resistance training remained the primary focus. Eligible studies had to assess physical outcomes such as muscle strength, muscular fitness, functional capacity, or performance. Studies were excluded if they were not RCTs, involved participants outside the adolescent age range, or included individuals with medical conditions that significantly affected physical functioning. In addition, studies were not included if the intervention did not involve resistance training, or if they focused solely on psychological or social effects rather than physical outcomes.

Results

Resistance training interventions in adolescents have consistently been shown to improve physical performance, functional capacity, and psychosocial outcomes. Programs conducted in school settings or targeting overweight youth increased muscle strength, upper body performance, and abdominal endurance, while also enhancing self-confidence and training skills (Kennedy et al., 2018; Mendonça et al., 2022; Schranz et al., 2014). Combined approaches that included resistance and aerobic training further contributed to reductions in body fat percentage and improvements in aerobic fitness (Mendonça et al., 2022). However, evidence also indicates that some benefits, particularly those related to self-confidence and functional improvements, may diminish if training is discontinued over time (Schranz et al., 2014; Kennedy et al., 2018). Overall, these findings suggest that resistance training, alone or in combination with aerobic exercise, provides meaningful enhancements in both physical and psychosocial domains in adolescents, highlighting the importance of consistent participation to maintain long-term effects. According to the PEDro assessment, the methodological quality of the studies was moderate to slightly above average, with scores ranging from 5 to 7 out of 10. The main limitation was the lack of blinding in the interventions. (PEDro Scale, 1999).

Conclusions

Our mini-review suggests that resistance training is an effective way for adolescents to improve muscle strength, muscular fitness, and functional capacity. Combined programs (resistance + aerobic training) may provide additional benefits for body composition and endurance. However, long-term benefits are not sufficiently studied: existing research shows that without continuous training, the effects may diminish.

In future research, there is a particular need for long-term RCTs (over 12 months) that monitor changes in physical functional capacity. It is also important to examine how the training environment (school, sports club, home) influences outcomes and adherence. In addition, digital support tools and motivational strategies may provide ways to improve adolescents’ training consistency. Long-term follow-ups (2–3 years) would help assess whether the benefits are maintained from adolescence into adulthood.

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Authors:

Mikko Happonen, Physiotherapy student, Savonia University of Applied Sciences

Antti-Jussi Räsänen, Physiotherapy student, Savonia University of Applied Sciences

Antti Virokannas, Physiotherapy student, Savonia University of Applied Sciences

Marja Äijö PT, PhD, Principal lecturer of Gerontology and Rehabilitation, Savonia University of Applied Sciences

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References:

Beam N, Fakhoury J & Myers A. 2017. Resistance training for children and adolescents https://tp.amegroups.org/article/view/14902/15748

Kennedy SG, Smith JJ, Morgan PJ, Peralta LR, Hilland TA, Eather N, Lonsdale C, Okely AD, Plotnikoff RC, Salmon JO, Dewar DL, Estabrooks PA, Pollock E, Finn TL, Lubans DR. 2018. Implementing Resistance Training in Secondary Schools: A Cluster Randomized Controlled Trial. Med Sci Sports Exerc. https://journals.lww.com/acsm-msse/fulltext/2018/01000/implementing_resistance_training_in_secondary.9.aspx

Mendonça FR, Ferreira de Faria W, Marcio da Silva J, Massuto RB, Castilho Dos Santos G, Correa RC, Ferreira Dos Santos C, Sasaki JE, Neto AS. 2022. Effects of aerobic exercise combined with resistance training on health-related physical fitness in adolescents: A randomized controlled trial. J Exerc Sci Fit. https://www.sciencedirect.com/science/article/pii/S1728869X22000181?via%3Dihub

Physiotherapy Evidence Database. PEDro Scale. 1999. In available: https://pedro.org.au/english/resources/pedro-scale/

Schranz N, Tomkinson G, Parletta N, Petkov J, Olds T. 2014. Can resistance training change the strength, body composition and self-concept of overweight and obese adolescent males? A randomised controlled trial. Br J Sports Med. https://www.researchgate.net/publication/255954538_Can_resistance_training_change_the_strength_body_composition_and_self-concept_of_overweight_and_obese_adolescent_males_A_randomised_controlled_trial

Picture: https://pixabay.com/fi/photos/k%C3%A4sipainot-keng%C3%A4t-lenkkarit-2465478/