Weekly Sets and Muscle Growth Insights

Aug 22, 2024

Muscle Growth and Set Recommendations

Overview of Opinions in Fitness Community

  • Diverse opinions on optimal sets for muscle growth.
    • Some advocate for low sets (1 set to failure).
    • Others argue that more sets lead to more growth.

Definitions and Technical Points

  • Set Definition: A bout of 8-12 repetitions, performed 3 or fewer reps from failure.
  • Focus on weekly sets per muscle group.
    • Compound Exercises: Involve multiple muscle groups (e.g., bench press).
    • Isolation Exercises: Target specific muscle groups (e.g., triceps skull crusher).

Research on Weekly Sets for Muscle Hypertrophy

Key Findings from Meta-analysis by Schoenfeld et al.

  • More weekly sets = more muscle growth.
  • Each additional set associated with a 0.37% increase in muscle size.
  • 9 or more sets per muscle group yield better hypertrophy than fewer.
  • Most studies focused on beginners (9-12 sets likely ideal for them).

Considerations for Trained Individuals

  • Mixed results from studies on experienced lifters:
    • 3 Studies: More sets are better.
    • 3 Studies: No benefit or regression after a certain point.

Support for More Sets

  1. Brigatto et al.:
    • 27 men (average 3.5 years training) trained with 16, 24, or 32 sets.
    • 32 sets showed greatest muscle growth.
  2. Radaelli et al.:
    • 48 men in two training conditions (biceps/triceps).
    • More sets favored (18-30 weekly sets).
  3. Schoenfeld et al.:
    • 34 men with 4.4 years training performed 6, 18, or 30 sets.
    • Higher sets led to increased muscle thickness.

Support for Fewer Sets

  1. Heaselgrave et al.:
    • 49 men trained with 9, 18, or 27 sets.
    • 18 sets showed optimal growth.
  2. Ostrowski et al.:
    • 35 men trained with 7, 14, or 28 sets.
    • 14 sets were sufficient.
  3. Aube et al.:
    • 35 men trained with 12, 18, or 24 sets.
    • No difference in muscle growth across groups.

Potential Explanations for Conflicting Results

Hypotheses

  1. Individual Differences:
    • Optimal sets may vary by individual response.
  2. Rest Intervals:
    • Short rest (60-90 seconds) vs. long rest (2-3 minutes).
    • Longer rest may enhance effectiveness of fewer sets.
    • Study by Longo et al. shows longer rests yield better results.
  3. Training Frequency:
    • Studies suggesting fewer sets had subjects train over only 2 days.
    • Potential for better results with distributed sets over 3+ days.

Conclusions from Research

  • Beginners: 9-12 weekly sets per muscle group.
  • Trained Individuals:
    • Long rest intervals: 12-18 sets could be sufficient.
    • Short rest intervals: 30-45 sets may be beneficial.
  • Progressing beyond 9-12 sets may be necessary if experiencing plateaus.

Recommendations for Practicing Individuals

  • If making progress, no need to change current training.
  • If plateauing or low response, consider increasing sets modestly (by ~20%).
  • Individual differences exist; some may do better with fewer sets.

  • Key Takeaway: The number of weekly sets and rest intervals significantly impact muscle growth, and adjustments may be necessary based on individual progress and experience level.