Quite often you’ll be told by a personal trainer or otherwise ignorant person that you should be stretching before you lift weights or go for any type of heavy workout.
Stretching is like squeezing the muscles beyond its relaxation point. It is lengthening the muscle fibers for PNS stimulation. Its is good relaxing feeling on the local joints, muscle tendons and ligaments. But they alone can't give you a proper warm-ups for intensive and straineous workouts. They do not assure a injury protection during all out efforts. there is not a single study has been done that proves that static stretching can in fact reduce your chance of injury, or make you perform better.
Our advice is to warm up with some lighter weights or at low intensity, properly, and to do a few minutes of low intensity cardio, to ensure that your joints are warm and your blood is flowing, before lifting heavy weights or go for high intensity activities.