“To improve range of motion and avoid injury, you do need to stretch, but don’t ever do it when muscles are cold.” – William Levine, MD, Orthopedics surgeon and director of sports medicine at Columbia University Medical Center in New York City.

You must start your warm up with some light aerobic free hand exercises to get the blood to your muscle tissue and before doing any stretching.
Why do you need to warm up?
Warm-up exercises are crucial before you do any workouts, or try to qualify for the above test – “Test your Potential.” Preparing the muscles and joints for more intense activity will prevent injury, and promote blood circulation. Warm-up exercises increase the temperature of the body and make the muscles more flexible and receptive to strenuous activity. An overwhelming number of experts will agree that you should first do warm-up exercises before stretching. Warming up should increase your heart rate but not to the level experienced during actual SPLITS.
Do the usual exercises that you do to warm and loosen up your muscles. Start from simple jogging to stretching. WARM UP your body to let your muscles relax especially the hamstrings and iliopsoas. These can specifically be termed as the “Muscles of the back of the thigh.”
It’s important to know the limits of warm-up exercises.
You must listen to your body. If you are feeling tired, uncomfortable or notice a decrease in performance, you may need more recovery time or a break from warm-up altogether. If you are feeling active, you do not force yourself to do the exercises slowly. If you pay attention, your body will let you know what it needs and when it needs to stop.
If you feel tired, it is better to do brisk walking or slow jogging for about ten to fifteen minutes, rather than stretching before exercise. The meaning of cooling down simply means slowing down, and never stopping altogether. Continuing to move around at a very low intensity for 5 to 10 minutes after a workout helps remove lactic acid from your muscles and may it will also contribute to reducing muscle stiffness.
What happens if you forget or don’t stretch?
If by chance you forget to warm up your body, you will or could eventually damage your muscles, cause pain, and surely will not be able to do splits. Remember, the fatigue from the vigorous workout will allow your muscles to relax. A good warm-up prepares your body for more intense activity. Warming up will allow your body time to adjust to the demands of exercise.
You should warm up for 5-10 minutes by doing some light exercises as outlined in the following chapter and then you should stretch. The reason for this is that stretching cold muscles can directly contribute to pulled and torn muscles.
Stretching, or should I say dynamic stretching will help your body to get ready for training. It’s also an essential part of recovering from a warm-up activity. Again, you should switch to stretching after warm up and all training sessions should also end with stretching.