Repetition Tempo and Muscle Growth: What Science Says About How Slow You Should Go
- Veronica Semeco
- Sep 8
- 3 min read
Introduction
When you think about hiring a personal trainer in NYC, you want more than just someone counting your reps—you want expert guidance rooted in science. That’s what sets The Parnell Plan apart. Recently, our very own Chris co-authored a meta-analysis on one of strength training’s most debated topics: Does repetition tempo influence muscle hypertrophy?
This groundbreaking research, titled “How slow should you go?”, reviewed 14 studies to answer a key question on Repetition Tempo and Muscle Growth: Do slow reps build more muscle than fast reps?
The findings might surprise you.
What Is Repetition Tempo?
Repetition tempo refers to how fast or slow you perform each rep of an exercise. A typical rep has two main phases:
Concentric (CON): Lifting the weight (muscle shortening).
Eccentric (ECC): Lowering the weight (muscle lengthening).
Trainers often prescribe tempos like “2-0-2” (two seconds up, no pause, two seconds down) or “3-1-3” (slower, more controlled).
The Research: Slow vs Fast Rep
Chris and his colleagues systematically reviewed 14 studies comparing slow vs fast repetition tempos.
Slow tempo (avg. ~3.5 seconds per rep)
Fast tempo (avg. ~1 second per rep)
Key Findings:
Both tempos led to muscle growth.
Faster tempos showed slightly higher results, but the difference was trivial.
No large-scale evidence that slow reps outperform fast reps.
👉 In short: Consistency, progressive overload, and good form matter more than whether you lift slow or fast.
Practical Takeaways for Your Training
As a client working with a personal trainer in NYC, here’s what this research means for you:
Choose tempo based on your goals.
Faster reps: more power and efficiency.
Slower reps: more control and mind-muscle connection.
Mix it up.
Different tempos can challenge muscles in unique ways.
Variety may prevent plateaus.
Don’t overthink it.
Hypertrophy depends on volume, intensity, and progression far more than tempo.
Why Work with a Science-Backed Personal Trainer in NYC?
The Parnell Plan isn’t just another gym program. Our coaches are:
Published researchers (Chris + Alec Piñero)
Industry mentors & professors
Dedicated trainers who apply research in real time
When you train with us, you’re not following fitness fads—you’re training with evidence-based methods proven to deliver results.
FAQs About Repetition Tempo and Muscle Growth
1. Does lifting slowly build more muscle? Not necessarily. Research shows both slow and fast tempos can build muscle, with no major difference in hypertrophy outcomes.
2. Should beginners focus on slow reps? Yes. Slower tempos can help beginners learn proper form and avoid injury.
3. What’s the ideal tempo for hypertrophy? Anywhere between 1–4 seconds per rep works, as long as volume and intensity are managed.
4. Are fast reps better for athletes? Faster tempos can mimic sport-specific movements, making them useful for athletes seeking explosiveness.
5. Can I mix tempos in one workout? Absolutely. Using a blend of fast and slow reps can challenge muscles in different ways and prevent adaptation.
6. Why hire a personal trainer in NYC for this? A skilled trainer will tailor repetition tempo to your body, goals, and experience level, ensuring safe and effective results.
Conclusion
The tempo of your reps isn’t the magic key to muscle growth—it’s just one of many training variables. The real secret lies in progressive overload, consistency, and expert guidance.
That’s where The Parnell Plan comes in. With a team of research-driven personal trainers in NYC, you’ll not only train smarter—you’ll also benefit from the very same science shaping the fitness industry.
👉 Ready to train with experts who publish research, not just workouts? Apply for a consultation with The Parnell Plan today.
🔗 Reference: Research Paper – How slow should you go? (Meta-Analysis)