The effect of eccentric phase duration on maximal strength, muscle hypertrophy and countermovement jump height: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized trials
PubMed 40692176 · doi:10.1080/02640414.2025.2535198
What was done
A systematic review and multi-level meta-analysis of five databases was conducted following Cochrane and PRISMA guidelines (pre-registered on OSF). Researchers compared resistance training outcomes between shorter eccentric duration groups (SEG) and longer eccentric duration groups (LEG) on maximal strength, muscle hypertrophy, and countermovement jump (CMJ) height. Effect sizes were estimated using Hedges' g with robust variance estimation, evaluated against a region of practical equivalence, and graded with Cochrane RoB 2 and GRADE criteria. The analysis included 9 studies comprising 166 participants (46% trained, 77% male).
What was found
Shorter eccentric duration enhanced CMJ height compared to longer duration with moderate certainty (g = -0.73, 90% CI [-1.34, -0.12], 90% PI [-1.34, -0.12]). Overall effects were uncertain for maximal strength (g = 0.25, 90% CI [-0.17, 0.67], 90% PI [-0.86, 1.36]) and muscle hypertrophy (g = 0.05, 90% CI [-0.22, 0.33], 90% PI [-0.54, 0.64]). Subgroup analyses found moderate certainty that longer eccentric duration led to equivalent or superior strength gains compared to shorter duration in trained individuals (g = 0.33, 90% CI [0.07, 0.60], 90% PI [0.07, 0.60]) and in volume-load matched trials (g = 0.25, 90% CI [0.04, 0.45], 90% PI [0.04, 0.45]).
Why it matters
These findings suggest eccentric tempo should be tailored to specific training goals: faster eccentric contractions favor explosive power adaptations like jump performance, whereas slower tempos may offer slight strength advantages for trained lifters when overall volume load is matched.
Limits
The total evidence base is small (9 studies, 166 participants) and heavily skewed toward male participants (77%). Wide prediction intervals for overall strength and hypertrophy indicate substantial between-study variability, and less than half of the pooled participants were resistance-trained.