Slowing Eccentric (Lowering) Tempo Can Enhance Muscle Hypertrophy, But the Evidence is Nuanced
High loads and slow exercises favor increased time under tension, which supports hypertrophic adaptations, particularly when using slower eccentric (lowering) phases rather than slower concentric (lifting) phases. 1
The Evidence on Tempo and Muscle Growth
What the Guidelines Tell Us
The most recent 2024 consensus statement on resistance training indicates that slow exercises with high loads increase time under tension during the eccentric action, which favors hypertrophic adaptations 1. However, this same guideline emphasizes a critical caveat: the absolute demands of the exercise are more important than the relative comparison of concentric and eccentric phases 1. In other words, total training volume and load matter more than obsessing over tempo alone.
Traditional resistance training guidelines recommend moderate tempo (3 seconds concentric, 3 seconds eccentric) for general populations 2, but these were not specifically designed to optimize hypertrophy.
What the Research Shows
The research evidence presents a more complex picture:
For the eccentric (lowering) phase:
- A 2025 meta-analysis found uncertain estimates for muscle hypertrophy when comparing shorter vs. longer eccentric durations (Hedge's g = 0.05), with evidence quality rated as low 3
- However, a 2022 study found that slower eccentric tempo (4 seconds vs. 2 seconds) produced greater hypertrophy specifically in the vastus medialis muscle, though other quadriceps muscles showed similar growth 4
- Another 2022 study demonstrated that the relationship between hypertrophy and strength gains was significantly stronger with slower eccentric contractions 5
For the concentric (lifting) phase:
- A 2025 meta-analysis comparing eccentric vs. concentric muscle actions found no statistical difference overall for hypertrophy 6
- The same analysis revealed that upper limb muscles, shorter interventions (≤8 weeks), and muscle thickness assessments favored eccentric actions 6
Practical Application: What This Means for Your Training
Focus on controlled eccentric tempo (3-4 seconds lowering) rather than explosive lowering, especially for upper body exercises like the bench press. Here's the algorithmic approach:
For Hypertrophy Goals:
- Use a 3-4 second eccentric (lowering) phase - this increases time under tension
- Maintain a standard 1-2 second concentric (lifting) phase - don't slow this down excessively
- Prioritize total volume and progressive overload - tempo is secondary to these factors
- Train 2-3 times per week with adequate volume (multiple sets of 8-12 repetitions) 1
Common Pitfalls to Avoid:
- Don't sacrifice load for tempo: Using weights that are too light just to achieve a slow tempo defeats the purpose. The guideline emphasizes "high loads and slow exercises" together 1
- Don't slow the concentric phase excessively: Research shows this doesn't provide additional hypertrophy benefits and may reduce total work capacity 4
- Don't ignore total volume: A 2015 study found that different tempos produced similar repetitions to failure at most intensities, suggesting volume matters more than tempo alone 7
The Bottom Line
Yes, slowing the eccentric (lowering) phase can enhance muscle hypertrophy, but this effect is modest and context-dependent. The 2024 consensus guidelines support using slower eccentric tempos to increase time under tension 1, but emphasize that absolute training demands (total volume, load, frequency) are more important than tempo manipulation alone 1.
For practical bench press training: lower the bar in a controlled 3-4 second tempo, press up explosively or at normal speed (1-2 seconds), and prioritize progressive overload with 2-3 training sessions per week using multiple sets of 8-12 repetitions at challenging loads.