Lifting lighter weights many times in a row might help grow certain slow-twitch muscles better because they stay working longer.

Lifting lighter weights might make your slow-twitch muscles grow more than your fast-twitch muscles, according to some new ideas.

Lifting heavy weights might make your fast-twitch muscle fibers grow bigger than your slow-twitch ones, according to some new research.

Lifting heavier weights makes your fast-twitch muscle fibers grow bigger than lifting lighter weights does.

Lifting lighter weights with more reps might make your slow-twitch muscles grow bigger than lifting heavier weights with fewer reps.

Resistance training to muscular failure induces equivalent hypertrophy in both slow-twitch (type I) and fast-twitch (type II) muscle fibers, regardless of load or repetition range.