Why do you warm up?  

This might be common sense, but prior to a workout, your muscles are cold. If you have not been doing any physical activity before resistance training, it can be very harmful to your muscles, joints, and tendons. Your goal is to get your body temperature up which will warm and loosen your muscles. Doing a small amount of cardio before your weight training workout has many benefits.

Defining Dynamic stretching:

Dynamic stretching as a kind of stretch that uses the momentum of a movement to complete its extension of the muscle groups. Arm circles, marches and walking lunges are all common examples of dynamic stretching. A dynamic stretch takes a specific movement and makes it a stretching activity, either by deliberate extension of the limb and corresponding muscle groups, or through other precise ranges of motion.

Benefits:

-The main benefit of using dynamic stretching is It activates muscles you will use during your workout. For example, a squat with a twist is a dynamic stretching exercise that engages your hips, legs, and core muscles.  We want to get their body warm and ready for the rest of the exercises we’ll be doing in class.  

-Improves range of motion and can help you feel more limber.

-Improves body awareness. Moving as you stretch challenges your balance and coordination; skills that could help your performance. It creates muscle memory for the exercises you’ll do later in class.

-Warming up in motion enhances muscular performance and power. Studies reveal dynamic stretching before a workout can help you lift more weight and increase overall athletic performance compared to no stretching or static stretching

Different Types: Static and Ballistic Stretching

Static stretching. it’s when you hold a stretch for 10 or more seconds while motionless. Because static stretching doesn’t use the same momentum that dynamic stretches rely on, it’s not the same in simulating sports performance. Static stretching can hurt your performance because loosening muscles and tendons in this manner leaves them less able to move quickly and on command come workout time. Static stretching should be used post-workout, or after each section that we work.

Ballistic stretching uses the momentum of a moving body or a limb in an attempt to force it beyond its normal range of motion. This is stretching, or “warming up”, by bouncing into (or out of) a stretched position, using the stretched muscles as a spring which pulls you out of the stretched position. Ballistic stretching, though often effective, has been associated with a high risk of injury, which is why dynamic stretching is a good choice for those who want to use stretching as an effective warm-up just before an event or training session.

https://greatist.com/fitness/full-body-dynamic-warm-up