Chronic Effects of Altering Resistance Training Set Configurations Using Cluster Sets: A Systematic Review and Meta-Analysis.

Background: The acute responses to cluster set resistance training (RT) have been demonstrated. However, as compared to traditional sets, the effect of cluster sets on muscular and neuromuscular adaptations remains unclear.

Objective: To compare the effects of RT programs implementing cluster and traditional set configurations on muscular and neuromuscular adaptations.

Methods: Systematic searches of Embase, Scopus, Medline and SPORTDiscus were conducted. Inclusion criteria were: (1) randomized or non-randomized comparative studies; (2) publication in English; (3) participants of all age groups; (4) participants free of any medical condition or injury; (5) cluster set intervention; (6) comparison intervention utilizing a traditional set configuration; (7) intervention length ≥ three weeks and (8) at least one measure of changes in strength/force/torque, power, velocity, hypertrophy or muscular endurance. Raw data (mean ± SD or range) were extracted from included studies. Hedges' g effect sizes (ES) ± standard error of the mean (SEM) and 95% confidence intervals (95% CI) were calculated.

Results: Twenty-nine studies were included in the meta-analysis. No differences between cluster and traditional set configurations were found for strength (ES = - 0.05 ± 0.10, 95% CI - 0.21 to 0.11, p = 0.56), power output (ES = 0.02 ± 0.10, 95% CI - 0.17 to 0.20, p = 0.86), velocity (ES = 0.15 ± 0.13, 95% CI - 0.10 to 0.41, p = 0.24), hypertrophy (ES = - 0.05 ± 0.14, 95% CI - 0.32 to 0.23, p = 0.73) or endurance (ES = - 0.07 ± 0.18, 95% CI - 0.43 to 0.29, p = 0.70) adaptations. Moreover, no differences were observed when training volume, cluster set model, training status, body parts trained or exercise type were considered.

Conclusion: Collectively, both cluster and traditional set configurations demonstrate equal effectiveness to positively induce muscular and neuromuscular adaptation(s). However, cluster set configurations may achieve such adaptations with less fatigue development during RT which may be an important consideration across various exercise settings and stages of periodized RT programs.