Loosen the hips with controlled swings before you train.
Stay tall and let momentum build gradually, don't yank from the start.
Front-to-back leg swings take one hamstring at a time through a progressively bigger arc, using controlled momentum to prepare the muscle for length rather than forcing a static stretch onto cold tissue. The glutes assist on every backswing, opening the hip and reminding it what full extension feels like. Done holding a rack before deadlifts, sprints or leg day, it's one of the highest-value thirty seconds in any warm-up.
Before training, yes. Dynamic swings warm the hamstrings and glutes through movement, which is what lifting and running demand. Save long static holds for after the session.
10 to 15 per side, letting the arc grow a little each rep. If the last few swings feel noticeably freer than the first, the drill has done its job.
Mostly straight but never locked. A soft knee keeps the swing smooth and the stretch on the hamstring, a rigidly locked knee tends to make the movement jerky and the hip guard against it.
