# Fitness Adaptations to a Combined Strength and Aerobic Training Program During the Transition Period in Young Soccer Players

**Authors:** Yiannis Michailidis, Andreas Stafylidis, Athanasios Mandroukas, Konstantinos Georgiadis, Georgios Karamousalidis, Georgios Antoniou, Angelos E. Kyranoudis, Eleni Semaltianou, Vasilios Mittas, Thomas I. Metaxas

PMC · DOI: 10.3390/sports14030088 · Sports · 2026-02-26

## TL;DR

A three-week training program during the soccer transition period improved body composition and aerobic performance in young players.

## Contribution

This study shows that combining aerobic and strength training during the transition period can maintain or improve fitness in young soccer players.

## Key findings

- Body fat percentage and fat mass significantly decreased after the training program.
- Aerobic performance, including anaerobic threshold time and movement speed, improved significantly.
- Resting systolic blood pressure also showed a significant reduction.

## Abstract

The annual soccer training cycle consists of preparatory, competitive, and transition periods. The transition phase is usually characterized by a decrease in training volume, which may lead to detraining and declines in physical fitness. The aim of this study was to examine the effects of a structured transitional training program on anthropometric characteristics, aerobic capacity, and jumping performance in young soccer players. Twenty-three under-17 players participated in the study and, following a two-week period of training cessation, completed a three-week program that included aerobic training three times per week (continuous and interval running sessions) and strength progressive resistance training twice per week. Pre- and post-intervention measurements were analyzed using paired-samples t-tests, with statistical significance set at p < 0.05. The results revealed significant reductions in body fat percentage (p = 0.016, d = 0.547), body fat mass (p = 0.018, d = 0.535), and resting systolic blood pressure (p = 0.024, d = 0.507). Additionally, time to reach the anaerobic threshold (p = 0.022, d = −0.515) and movement speed at the anaerobic threshold (p = 0.029, d = −0.487) significantly increased. No significant changes were observed in the remaining variables. These findings indicate that a three-week transition-period training program combining structured aerobic running drills with progressive resistance training can induce favorable adaptations in selected anthropometric and physiological parameters in youth soccer players. However, the lack of a control group should be considered when interpreting the magnitude of the program’s effects.

## Full-text entities

- **Diseases:** fatigue (MESH:D005221), reduction in systolic blood pressure (MESH:D007022), stroke (MESH:D020521), injury (MESH:D014947)
- **Chemicals:** caffeine (MESH:D002110), oxygen (MESH:D010100), VO2 (-)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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## References

39 references — full list in the complete paper: https://tomesphere.com/paper/PMC13029815/full.md

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Source: https://tomesphere.com/paper/PMC13029815