Study timeline: 3-week baseline period (Weeks 1–3) for reliability & workload quantification, followed by the 5-day overreaching phase (Days 19–23, workload sum 934 AU vs. 423 AU baseline), then follow-up testing at P72h, P1W and P2W. CMJ and 10-5 hop tests were performed at all timepoints.
Gardner-Altman plots showing paired mean differences (N=15) for four significant external load metrics between baseline week 3 and the high-intensity training period (HI TP). Each line = one athlete. The right half of each plot shows the bootstrapped mean difference and 95% CI.
2,099 → 3,106 AU — Very large increase. Total load across all movement planes nearly doubled during overreaching week.
423 → 934 AU — Largest effect size observed. High-intensity accelerations (3.6–5.0 m/s²) more than doubled, reflecting the nature of repeated sprint/jump drills.
375 → 858 AU — Very large increase. Sustained accelerations >5.0 m/s² more than doubled.
5,120 → 11,581 m — Very large increase. Distance at >4.0 m/s² threshold more than doubled. ALM not significantly different between weeks.
Individual athlete change-from-baseline scores for six key CMJ metrics. Light grey band = MD threshold; dark grey band = SEM. Points colored by performance change relative to threshold. (A) mRSI; (B) Braking Phase Duration; (C) Braking Net Impulse; (D) Avg Braking Velocity; (E) Jump Height; (F) Jump Momentum.
Individual athlete change-from-baseline scores for three 10-5 hop test metrics across all post-baseline timepoints. (A) Top 3 avg mRSI; (B) Top 3 peak mRSI; (C) Top 3 avg jump height. Notable secondary reduction in performance observed at P1W, consistent with the bimodal SSC recovery model.
Athlete-specific slope coefficients for jump height (cm) derived from random intercept and slope models across all 5 post-baseline timepoints (A1, A2, P72, P1W, P2W). Grey band = MD threshold. Red lines = athletes exceeding the MD threshold. Visualises the high degree of individuality in fatigue response and recovery timelines.
The figure above reveals high inter-individual variability in fatigue response — some athletes recovered by P72h while others still exceeded the MD threshold at P1W or P2W, despite the same exposure to the overreaching stimulus.
Practical application: Athlete-specific slope coefficients from random intercept & slope models allow sport scientists to generate individualised recovery timelines, enabling targeted training modifications or additional recovery interventions for athletes still below threshold.
MD threshold note: The MD approach used in this study is more conservative than CV or SWC methods — meaning athletes coloured red truly represent meaningful, real changes beyond measurement noise.
Note: T3 Jump Height from 10-5 hop showed only moderate inter-day ICC (0.66) with wide CI — interpret with caution. CMJ metrics generally showed excellent reliability (ICC ≥0.90).
① Monitor the eccentric phase of the CMJ. Average braking velocity and braking net impulse were the most sensitive CMJ metrics (ES up to 1.04; 75% below MD). These eccentric-phase metrics remained depressed beyond 2 weeks in some athletes — more so than traditional outcome metrics like jump height.
② Include a fast SSC test alongside the CMJ. The 10-5 hop test captured a bimodal recovery pattern not evident in the CMJ alone. High ground-impact SSC tasks appear more sensitive to the delayed, neural phase of recovery — particularly relevant during densely scheduled seasons.
③ Decompose ratio metrics before interpreting. In this study, decreases in mRSI were almost entirely driven by reductions in jump height, not increases in TTT. This matters for informing training decisions — a drop in mRSI doesn’t always mean jump strategy changed.
④ Use mixed-effects models for athlete-level insight. The random intercept & slope model approach generates athlete-specific trajectories, revealing individuals who recover slowly despite the group average improving. This enables personalised recovery interventions rather than blanket team-level decisions.
⑤ Don’t stop follow-up testing at 72h. True recovery from a high-intensity overreaching phase may take up to 2 weeks. Several athletes remained below MD thresholds at P1W and P2W. SSC fatigue presents in a bimodal fashion — both immediate metabolic effects AND delayed neural/structural disruption must be accounted for.