Effect of cluster set resistance training combined with high-intensity interval training on cardiorespiratory and muscular fitness in untrained young men.

Plain-language summary

This study compared two ways of organising the same lifting session in untrained young men. The test method was cluster set resistance training, meaning a set is broken into small chunks with a short rest between them (three lots of three reps rather than one straight set of nine, say) so that bar speed and power stay high through the whole set instead of collapsing at the end. The comparison method was traditional resistance training, meaning the set is done straight through with rest only once it is finished. Both groups added the same high-intensity interval training, meaning short all-out bursts such as 30 seconds hard on a bike, separated by easy recovery periods. Twenty-two men were randomly assigned to one method or the other and trained for 12 weeks. Both groups improved substantially and by about the same amount: heavier one-rep maxes in squat, bench press, deadlift and rowing, more volume at 70% of their max, longer standing long jumps, thicker chest, biceps and thigh muscles, higher maximum oxygen uptake, and a significant drop in body fat percentage. No measure separated the two methods. With 22 men split across two groups, a real but modest advantage to either method could easily have gone undetected.

Key findings

• Both the chunked-set and the straight-set group increased their one-rep max (the heaviest weight they could lift once) in squat, bench press, deadlift and rowing.
• Both groups gained muscle thickness in the chest, biceps and front of the thigh.
• Body fat percentage dropped significantly in both groups.
• Maximum oxygen uptake, a measure of cardiovascular fitness, improved in both groups.
• Neither way of arranging the sets beat the other on any measure.