Cluster Sets for Hypertrophy
Are they any better than traditional sets for building muscle?
This study compared the effects of cluster sets (CS) and traditional sets (TS) on muscle growth in resistance-trained individuals, addressing the limitations of previous research by matching effort levels between protocols.
Key Points
CS involve breaking up a set into smaller clusters with short rest periods
Previous studies comparing CS and TS often didn't match effort levels, potentially biasing results
This study matched sets, reps, and effort (measured by repetitions in reserve) between CS and TS
Aim
To compare muscle hypertrophy between CS and TS protocols when matched for volume and effort.
Methods
10 resistance-trained participants (7 men, 3 women)
8-week training period, 2 sessions per week
Unilateral design: one leg did CS, the other did TS
CS: 5 sets of 3 clusters of 4 reps with 20s rest between clusters
TS: 5 sets of 12 reps
Both protocols adjusted load to 0-1 repetitions in reserve
Measured muscle thickness via ultrasound and lean mass via DXA
Results
Both CS and TS led to similar increases in muscle thickness (p < 0.001, ES = 0.56 for CS; p = 0.012, ES = 0.42 for TS)
Both protocols resulted in similar increases in lean tissue mass (p = 0.002, ES = 0.11 for CS; p < 0.001, ES = 0.13 for TS)
Practical Takeaways
CS can be an effective alternative to TS for muscle growth
When effort is matched, CS and TS produce similar hypertrophy
CS may allow for higher loads while maintaining effort, potentially benefiting strength gains
Lifters can use CS to add variety to their training without sacrificing muscle growth
