Rate of Force Development (RFD): physiological and methodological considerations
Explosive strength
Key Findings
RFD = the slope of the force-time curve during a rapid contraction; used to characterise explosive strength of athletes, elderly individuals and patients
Early phase (first 50-75 ms of an explosive contraction): RFD seems mainly determined by the capacity for maximal voluntary activation, particularly increased motor-unit discharge rate
Full text, checked 2026-09-27: the later phase of the force rise is strongly associated with maximal strength (MVC), which depends on neural drive and muscle cross-sectional area; fibre type is linked mainly to the early phase
RFD can be improved by both explosive-type and heavy-resistance strength training, in different populations — mainly through faster muscle activation
Methodology: RFD is "quite difficult to evaluate in a valid and reliable way"; the review gives recommendations for quantifying it in laboratory and clinical settings — only identical methods can be compared correctly
Practical Application
Narrative review from the leading RFD group: explosive strength in the first 50-75 ms of a contraction is set mainly by rapid voluntary activation (motor-unit discharge rate), and both explosive-type and heavy-resistance training improve it, mainly by speeding muscle activation; measuring it validly is hard. For a masters athlete this means explosive intent, not only heavy slow lifts, trains the early force rise.
Inference, not tested here: include an explosive component (jumps, ballistic movements, Olympic-lift derivatives with the intent to accelerate) alongside heavy work; "intent to move fast" at submaximal load targets the activation-driven early phase
Direct transfer: sprint starts, in-race accelerations, reaction to terrain (cycling), fall resilience — the review names athletes, elderly individuals and patients as the populations where RFD is assessed
Limitations
Narrative review, not a meta-analysis of effect sizes
Methodological heterogeneity of RFD measurements complicates direct comparisons between studies
How this entry was checked and changed
Why this level
(foundational mechanistic review)
Content correction 2026-09-27
"Early phase (<100 ms) / late phase (>100 ms)" -> the abstract gives the early phase as the first 50-75 ms; the late-phase determinants are labelled full-text content.
"With age RFD declines faster than maximal strength" -> not in the abstract; removed. Lead bullet now carries the review's own conclusions; training suggestions labelled as inference.
Sport "strength, sprint" -> "strength".
Lines labelled "full text; not checked" were read against the open-access full text (PMC4875063): 1 corrected to what the paper says.