Before embarking on your main workout we need to prepare the body for exercise. If we run straight into your workout there is a high probability we can cause an injury. Some injuries may last a few days such as a strain, and some could last for weeks or months such as a tear.
There are many benefits of warming up such as increased blood circulation, improved muscle co-ordination, increased elasticity of the muscles and a reduced chance of an injury occurring.
What warms should be do? Should I do static stretching or mobility work?
The short answer is mobility at the start and static stretching at the end.
Mobility work has the advantage of lengthening soft tissue with movement, thus allowing them to fire from the very beginning. Not only that, your activating your central nervous system (CNS) that sends messages to muscles to move. From the first repetition your body is ready to go.
Static stretching wants to be done at the end of the workout. At this point the body should still hot/warm and here you can apply gently tension on a muscle by holding it for 15 seconds before changing.
This is lengthening your muscles giving them more flexibility.