What is it?
Dynamic stretching is a form of stretching that utilises rapid movements which pull the muscle into its end range. Unlike static stretching it is not held here but allowed to fall back, or lowered back to the starting position and the cycle continues. A common example is swinging the leg to stretch the hamstrings, forcefully swing your leg to get it up high so you could kick your hands if held in front of you. Then allow the leg to drop back to your side and kick up again. Start this stretching slowly with little kicks and gradually get faster with progressively longer motions. Starting too fast through the full range of motion is not recommended as this may cause injuries if performed cold.
Benefits compared to static stretching?
Unlike static stretching dynamic stretching increases power, strength and speed compared to before stretching. This is due to an increase in muscle temperature. When our muscles temperature increases, the energy production and rate of contraction also increases. If we can produce more energy we can produce more force (strength) and if we can contract the muscle faster then we will produce more power. Overall there are only benefits to this stretching if you want to prepare for any form of exercise.
When to do?
Dynamic stretching is best used in the warm-up, primarily because it literally warms you up. This has knock on effects that are ideal before working out or playing your sport. It is recommended over static stretching in the warm-up for the following reasons.
Increase range of motion
Start swinging slowly in limited range of motion
Gradually increase range of motion
Gradually increase speed of stretching