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[@RenaissancePeriodization] Rep Speed for Muscle Growth: Did I Overhype Slow Reps?

· 3 min read
[@RenaissancePeriodization] Summarizer
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@RenaissancePeriodization - "Rep Speed for Muscle Growth: Did I Overhype Slow Reps?"

Link: https://youtu.be/reiB9uQ6O4E

Short Summary​

Dr. Mike Israel clarifies a common misunderstanding that he and Jared Feather advocate for "super slow" training for everyone. While they frequently cue slower eccentrics, especially during instructional sessions with pro-bodybuilders and new clients, this is primarily for safety, improving mind-muscle connection, and facilitating on-the-fly technique adjustments. They assert that once trainees are proficient and safe, faster eccentrics are equally effective for muscle growth, a finding supported by scientific literature.

Key Quotes​

Key Quotes​

  1. "folks very understandably assume that Jared and I are pro slow, that we think this is the way to train for everyone. But we flubbed. it's our bad."
  2. "going slower is safer categorically."
  3. "if you're confident that you won't get hurt, you can connect just fine with your muscles, and your technique, the actual pattern of movement is rock solid, not just a free-for-all, feel free to go as fast on the eentric as you like."
  4. "controlled concentrics that are intentionally slow kind of just suck the life out of you. They're not fun."

Detailed Summary​

  • Dr. Mike admits to being wrong about the perception that he and Jared Feather universally recommend "super slow" training.
  • The misconception arose from their consistent cues to clients, particularly pro-bodybuilders and new trainees, to perform slower eccentric phases and pauses at the bottom of movements.
  • They explain that these specific cues are given for three primary reasons:
    • Safety: Slower movements reduce kinetic energy, minimizing injury risk, especially for strong athletes with potentially lagging tendon integrity.
    • Mind-Muscle Connection: A slower pace helps trainees better connect with and activate target muscles (e.g., quads over glutes).
    • Technique Adjustment: Slower movements provide opportunities for immediate, on-the-fly technical corrections from coaches, making each rep an instructional moment. This is crucial for new clients learning their training approach.
  • Faster eccentrics are perfectly acceptable once safety, proper technique, and mind-muscle connection are established.
  • Scientific literature consistently shows that eccentric phases between 1 and 6 seconds yield similar muscle growth (hypertrophy) benefits, provided sets are taken to muscular failure.
  • Slow eccentrics remain beneficial for learning new techniques, enhancing safety, improving mind-muscle connection, or simply for adding training variation.
  • For the concentric (lifting) phase, moving as fast as possible is generally fine with a slight increase in risk; a 1-2 second concentric is good for less risk.
  • Intentionally slow concentrics are generally not recommended as they can be demotivating and do not offer superior hypertrophy benefits.
  • Crucially, during the eccentric phase, muscles must actively resist the weight, not just "dump" it, to achieve full muscle growth benefits.
  • The RP Hypertrophy app is mentioned as a tool that demonstrates initial reps with a slightly slower cadence for learning, allowing users to increase speed as proficiency grows.