To prevent injury and to improve your performance, always stretch after your muscles are warm and blood has circulated through them. A good warm-up consists of at least 5-10 minutes of low intensity cardio to warm up your lower body muscles
 
A gradual warm-up should always precede exercise. This helps you improve performance, prevent injury, improve your posture and feel good. Here are three great warm-up stretches. You need only hold each for 8 to 12 seconds. It's important to do the stretch slowly without bouncing.
 
A proper warm-up consists of:  
Warming your body
This involves gradually increasing your heart rate, body temperature and breathing rate. A good indication that your body is warm is that you’ll begin to feel warm and may even break a sweat. To best achieve these responses, gradually increase the intensity of how hard you’re exercising but keep it light to moderate. For example, if walking, take bigger steps, gradually walk faster or even swing your arms more.