Author Identifier (ORCID)
Abstract
Force-plate countermovement jump (CMJ) testing is widely used to assess neuromuscular status, yet monitoring interpretation often relies on best-trial values from abbreviated protocols, potentially biasing conclusions when the session maximum occurs beyond the sampled attempts. We mapped peak-trial timing across a six-trial clustered (3 + 3) CMJ protocol for seven outcome and strategy force–time metrics, and tested whether this peak-trial pattern was preserved between personal best (PB) and typical state (TS) monitoring sessions, both defined using modified reactive strength index (mRSI) as the primary selection variable. Retrospective dual-force-plate data (1000 Hz; August 2020–December 2025) were analysed from 314 athletes who performed two sets of three maximal no-arm-swing CMJs (5–10 s between repetitions; 60–90 s between sets). Peak-trial distributions deviated from uniform for all metrics (all Bonferroni-adjusted p ≤ 3.4 × 10−3; Cramér’s V = 0.12–0.26). On PB days, the most frequent peak occurred on repetition 4 for output metrics (25.8–30.3%) and propulsive power (29.3%), on repetition 6 for braking force/power (31.2–34.1%), and on repetition 1 for stiffness (27.4%) and propulsive force (31.8%). Critically, peak-repetition distributions were nearly identical between PB and TS days for every metric (all p ≥ 0.386; Cramér’s V ≤ 0.091).
Keywords
force–time variables, neuromuscular monitoring, performance profiling, testing protocol, testing standardisation, vertical jump
Document Type
Journal Article
Date of Publication
1-1-2026
E-ISSN
1466447X
ISSN
02640414
Volume
44
Issue
16
PubMed ID
42590826
Publication Title
Journal of Sports Sciences
Publisher
Taylor & Francis
School
School of Medical and Health Sciences
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
First Page
2180
Last Page
2195
Recommended Citation
Kruczek, K., Karpęcki, S., Gabbett, T., Lake, J., & Nowak, M. (2026). When does the peak countermovement jump performance occur? Mapping peak-trial timing across six clustered repetitions. Journal of Sports Sciences, 44(16), 2180–2195. https://doi.org/10.1080/02640414.2026.2712762