Quadrant training: a simple typology-based approach to improve strength and endurance in youth soccer players
Timo Steidle, Benedikt Johannes Meixner, Mascha Lenk, Marcelle Schaffarczyk, Billy Sperlich · Frontiers in Sports and Active Living · 2026
Introduction: Youth soccer players show heterogeneous performance profiles, yet individualized conditioning is often impractical outside professional settings. We examined whether a typology-based training allocation into four quadrants (“Quadrant Training”; QT) improves endurance- and strength-related performance compared with regular soccer training alone.
Methods: Male U16-U17 players from two youth academies completed a non-randomized, longitudinal controlled intervention (academy-level and intervention effects are confounded); one academy served as intervention group ( n = 38), the other as control ( n = 22). Players were classified into four endurance quadrants, i.e., below and above team mean based on 30-15 Intermittent Fitness Test velocity [vIFT] and velocity at 4 mmol·L⁻¹ blood lactate [V4] and four strength quadrants based on relative isometric mid-thigh pull strength [IMTP] and countermovement jump height [CMJ], completing quadrant-specific endurance training plus one weekly strength session.
Results: Between-group ANCOVA models using heteroscedasticity-robust standard errors showed the most precise effect for CMJ ( p = 0.020), with V4 ( p = 0.066) and vIFT ( p = 0.054, favoring controls) showing smaller effects and IMTP showing no between-group difference ( p = 0.490). None of these effects survived correction for multiple comparisons (adjusted p = 0.078-0.490). This CMJ effect was itself baseline-dependent, negligible at low baseline values and more pronounced at higher ones. For descriptive comparison, the intervention group improved significantly in V4, CMJ, and IMTP (all p ≤ 0.05), while controls showed no significant pre-post changes in any outcome. Exploratory individual responder analyses showed the highest proportion of improvers for V4 and IMTP, followed by CMJ.
Discussion: QT proved feasible to implement as an individualized training framework, and effect sizes for V4 and CMJ suggested a beneficial impact on submaximal endurance capacity and explosive lower-body power. These preliminary
Findings: warrant confirmation in adequately powered trials.