Does slow, no-relaxation squatting make you more powerful?

Usui and colleagues tested the prediction that slow, constant-tension squats (LST) would build size and strength but not power. Healthy young men squatted at 50% of 1RM, either LST (3 s lowering and 3 s lifting without a pause, n = 9) or normal speed (1 s lowering, 1 s lifting with a 1-s pause, n = 7), 10 repetitions per set, 3 sets a session, 3 sessions a week for 8 weeks.

The normal-speed group changed nothing. The LST group increased quadriceps muscle thickness by 6-10%, isometric hip extension torque by 18% and squat 1RM by 10%, but not isometric knee extension torque, lifting power from a squat position, the rate of EMG rise in the knee extensors during that lift, leg extension power or vertical jump height.

The authors conclude that LST can increase muscle size and task-related strength but has little effect on power in fast, explosive movements.

How this relates to the Russian static-dynamic method: the closest tested form for the squat: 50% 1RM, 3 s down / 3 s up, no pause or relaxation between reps, a fixed 10 repetitions (about 60 s per set, our calculation), 3 sets. Whether sets reached failure, the rest between sets and the squat depth are not in the abstract. No endurance, mitochondrial or capillary outcome.