No — stretching cold muscles is like stretching a brittle rubber band. You should always bring your heart rate up before stretching, about 5 minutes or until you start to break a sweat. After you get blood circulating, it is time for a warm-up stretch that will prepare your muscles for the demands of a work out. Walking toe touches for hamstrings, and hip crossovers for core and back are great for your warm-up. Save the deeper, longer stretches for your cool down.
Don’t rush out of the gym! The cool down or post work out stretch is just as important as the pre-lifting stretch. Schedule 5 minutes or so and reset your muscles. The pay off: injury prevention, quicker recovery time and stress reduction for your muscles.