Everyone knows we should rest in between exercises when working out. Its common practice to perform multiple sets of a given exercise, with a rest period in between each set. This allows us to recover enough to push harder on the subsequent set, meaning we can train at a higher workload percentage.
What Are Cluster Sets?
Cluster sets is a method of training which involves resting within a set. Generally, a cluster set involves the inclusion of short (10-45 seconds) rest periods in between individual repetitions within a set.
The idea is that this short rest is enough to reduce fatigue, meaning greater muscle recruitment in the following rep, so that you can stay at a heavier weight for more repetitions. You're aiming for greater work done at the end of the set, compared to if you were following a traditional set structure with no rest, where you might be aiming to complete 8 reps with 50g weight for example, but could only complete 6 on the last two sets due to fatigue.
Now For The Science Bit
Research has demonstrated the use of cluster sets to be most beneficial for power or explosive exercise.
This is due to the need for intention of maximal velocity during power exercises and the high requirement of muscle fibre recruitment. Additionally, power exercises, such as the Olympic lifts have a high technical element, so that rest between reps often allows for greater movement quality throughout the set. Research has shown that when using cluster sets in sets of Olympic lifts, the bar speed remains higher throughout the set compared to when using a regular set structure. However despite acute benefits being demonstrated, research is inconclusive when looking at cluster sets over a longer term.
So cluster sets appears to be a beneficial method during power training. However with regards to strength training, results have been mixed. Research has generally shown that the use of cluster sets in strength and endurance training resulted in lower strength gains and less metabolic response compared to using a traditional set structure. Additionally, the use of cluster sets during hypertrophy training has also shown to result in less size increases than a traditional set structure at the end of 6 weeks training. Therefore it seems reasonable to conclude that cluster sets is not a method for use all year round, in all training programmes (sorry if you enjoy your extra rest!). Save it for power/explosive training.
How Do I Use Cluster Sets In My Training Programme?
In terms of the optimal resting time during a cluster set, research is inconclusive. Studies have used between 2-130 seconds rest, however more favourable results seem to suggest the use of a 10-45 second rest between reps. This rest appears to optimise power training when using between 1-5 reps within a set.
Let us know in the comments below what you think & share with your training buddy!