Effect of Fartlek Training on VO₂max in Adolescent Athletes: A Systematic Review

Abstrak

Background: Maximal oxygen uptake (VO₂max) is an important indicator of cardiorespiratory fitness and athletic performance in adolescents. Fartlek training, which combines variable-intensity exercise within continuous activity, is commonly used to improve aerobic capacity; however, evidence regarding its effectiveness in adolescent athletes remains limited and inconsistent.

Objective: To evaluate the effectiveness of fartlek training in improving VO₂max among adolescent athletes.

Methods: This systematic review followed the PRISMA 2020 guidelines. Literature searches were conducted in Google Scholar, Semantic Scholar, and Crossref for studies published between 2015 and 2025. Experimental and quasi-experimental studies involving adolescent athletes aged 12–18 years were included based on predefined PICOS criteria. Two independent reviewers performed study selection and data extraction. Due to heterogeneity in study design and outcome measurement, findings were synthesized narratively. Risk of bias was assessed using standardized criteria.

Results: Of 1,187 identified records, nine studies involving approximately 186 participants met the inclusion criteria. All included studies reported improvements in VO₂max following fartlek training, with increases ranging from 1.0 to 11.6 mL/kg/min. Greater improvements were generally observed in interventions lasting 4–8 weeks with frequencies of 2–4 sessions per week. Comparative studies showed that fartlek training produced effects comparable to or greater than other training methods. However, variability in protocols and measurement methods limited quantitative synthesis.

Conclusion: Fartlek training appears effective in improving VO₂max among adolescent athletes, although the certainty of evidence remains low to moderate due to methodological limitations and heterogeneity.