Depending on how fast you lower weights during strength training, your muscles might work together differently — some fast techniques make opposing muscles activate more, others make them activate less.

Lowering weights slowly turns on different cellular signals and makes your muscle’s scaffolding change more than lifting does—even if both make your muscle bigger.

In untrained individuals, compound resistance exercises improve strength in isolated movements more effectively than isolation exercises alone due to enhanced neuromuscular coordination and motor learning.

Slowing down the lowering part of a lift (like slowly lowering a dumbbell) makes your muscles more damaged and triggers more repair and growth than quickly lowering it.

If young, healthy guys do strength training for 12 weeks using different types of muscle contractions—whether slow or fast—they’ll get significantly stronger in their thigh muscles, no matter which style they pick.

For women new to lifting weights, doing slow reps with longer muscle contractions builds more muscle strength and size faster than regular-speed lifting at the same effort level over 6 weeks.