REF-691 · Jiménez-Reyes, Samozino, Brughelli & Morin, 2017 · Frontiers in Physiology, · Paper · PubMed
Training individualised to each athlete's force–velocity imbalance improved jumping more consistently than a generic program
Participants
n=84, assigned to an "optimized" group (split into velocity-deficit, force-deficit and well-balanced sub-groups by each subject's F-v imbalance), a "non-optimized" group (one classical program for all) and a control group. All did a 9-week resistance training program.
Protocol
Three-group training intervention: eighty-four subjects assigned by their force-velocity imbalance (FVimb) to an "optimized" group (velocity-deficit, force-deficit and well-balanced sub-groups), a "non-optimized" group following one classical program, or a control group (from the abstract)
All subjects underwent a 9-week specific resistance training program; the optimized programs were designed to reduce each sub-group's FVimb
Measures: unloaded squat-jump height, FVimb and maximal lower-limb power output (Pmax)
Key Findings
Every subject in the optimized sub-groups improved squat-jump height: velocity-deficit +12.7 ± 5.7% (ES 0.93), force-deficit +14.2 ± 7.3% (ES 1.00), well-balanced +7.2 ± 4.5% (ES 0.70). In the non-optimized group the results were much more variable and unclear.
The gains came with a markedly reduced F-v imbalance (force-deficit −57.9 ± 34.7%, velocity-deficit −20.1 ± 4.3%), while maximal power changed little or unclearly (force-deficit −0.40 ± 8.4%, velocity-deficit +10.5 ± 5.2%).
The authors conclude that reducing the imbalance improved jumping even without raising maximal power.
Practical Application
In n=84 subjects over 9 weeks, training aimed at each person's own force–velocity deficit improved squat-jump height in every individual (sub-group means +7.2% to +14.2%), while one generic program gave variable, unclear results — profile the athlete and bias toward heavy (force) or ballistic (velocity) work depending on which side is limiting.
Inference, not tested: re-profile periodically, since the imbalance is what the program shifts.
Limitations
Single study; the outcome is unloaded squat-jump height — transfer to sprinting or cycling power is not tested here.
F-v profiling is methodology-sensitive and needs valid measurement.
How this entry was checked and changed
Content correction 2026-09-27
Type "Randomized controlled intervention" -> controlled three-group intervention (the abstract does not describe randomisation; optimized sub-groups were assigned by F-v imbalance). Sport "strength, power" -> "strength".
Added the abstract's sample (n=84), per-sub-group jump gains, F-v imbalance and power changes; "substantially more" -> "more consistently" (the abstract reports the non-optimized group as variable/unclear, not a head-to-head difference).
Re-profiling advice relabelled as inference.
2026-09-28: added Protocol from the abstract (Europe PMC/PubMed PMID 28119624).