A heavy circuit (6RM, about 35 s between sets) built the same bench press and half-squat 1RM, bench press power and lean mass as the same sets with 3-min rests in 33 resistance-trained men over 8 weeks, in shorter sessions; only the long-rest group raised 30-s Wingate peak power, and only the circuit group lowered % body fat

Alcaraz and colleagues asked whether a heavy-load circuit, which shortens the rest between sets, brings the same adaptations as traditional strength training with long rests.

Thirty-three healthy men were randomised to a high-resistance circuit (HRC: 3-6 sets of 6 exercises at 6RM, about 35 s between sets), traditional strength training (TS: the same sets and loads with 3 min between sets) or a control group; both training groups lifted three times a week for 8 weeks.

Before and after, the authors tested bench press and half squat 1RM, bench press peak power, body composition by DXA, a shuttle run and a 30-s Wingate test. Both training groups raised upper- and lower-limb 1RM to the same extent, produced more bench press peak power across loads (p ≤ 0.01), ran the shuttle better and gained lean mass but not bone mass.

Wingate peak power rose only after TS (p ≤ 0.05), and % body fat fell only after HRC. The authors conclude that HRC gives a strength and mass adaptation similar to traditional training while taking less session time.