A small study of 16 resistance-trained young adults compared two ways of doing resistance training: cluster sets (short rests between reps) and traditional sets (all reps in a row). The researchers measured how people felt during and after each session, including mood, energy, enjoyment, and how hard the workout seemed.
They found that during traditional sets, people's mood dropped and they felt more drained. But with cluster sets, mood stayed steady and people reported higher enjoyment and lower perceived effort. The difference was large enough to be meaningful, with effect sizes ranging from 0.7 to 1.2.
This was an acute study, meaning it only looked at one session. It did not track long-term effects or whether cluster sets lead to better workout habits over time. No safety issues were reported, but the study was too small to draw broad conclusions.
The takeaway is that how you structure your rest during weight training can change how you feel in the moment. Cluster sets might make workouts more enjoyable and less grueling, which could help some people stick with their routine.
