Slowly Lowering Your weights v Fast Eccentric Phases
Which is better for size, strength and power?
It turns out that we still don’t know a lot about the effects of different rep speeds, particularly during eccentric phases.
This systematic review and meta-analysis looked at the effects of eccentric phase duration on maximal strength, muscular hypertrophy, and countermovement jump (CMJ) performance in training.
Key Points
Compared fast eccentric group (FEG) and slow eccentric group (SEG) protocols
Analysed 8 studies with 148 participants (52% trained, 80% male)
Used random-effects multi-level meta-analyses with robust variance estimation
Assessed evidence quality using Cochrane RoB 2 and GRADE criteria
Methods
Databases searched: PubMed, CINAHL, SPORTDiscus, ProQuest, and Google Scholar
Inclusion criteria: Studies on eccentric phase duration, published in English, healthy participants, minimum 4-week duration
Outcomes analysed: Maximal strength, muscle hypertrophy, and CMJ performance
Results
CMJ performance: FEG showed practically worthwhile enhancement (Hedge's g = -0.73 [90% CI = -1.34, -0.12])
Maximal strength: Uncertain estimates (g = 0.18 [90% CI = -0.27, 0.63])
Muscle hypertrophy: Uncertain estimates (g = 0.03 [90% CI = -0.30, 0.36])
Subgroup analyses:
Trained participants: SEG led to equivalent or enhanced strength gains (g = 0.33 [90% CI = 0.07, 0.60])
Volume-load matched trials: SEG showed similar or higher strength increases (g = 0.25 [90% CI = 0.04, 0.45])
Practical Takeaways
Fast eccentric movements may improve jumping performance.
For trained individuals, slower eccentric phases could lead to similar or better strength gains.
When volume-load is matched, slower eccentric phases may result in comparable or superior strength improvements.
