All that means is you should stretch for a few minutes after each workout. If you need to figure out a major muscle group, take a look at my story, Pump Your Muscles Too . Actually, stretches before a workout should be easy and are only meant to loosen you up. The real flexibility session comes afterward, when our muscles have turned into supple taffy. Pay special attention to the part of the body used in your activity, for example, shoulders for tennis and legs for cycling, but that doesn't mean ignore everything else.
Several muscles are important for everyone to stretch , all the time.
To stretch them while standing, lift your heel to your buttocks, grabbing the ankle with the same hand as leg. Tighten your abdominals, push your hips forward slightly while you push your ankle away from you against the resistance of your hand. The same stretch can be done lying face down on the floor. Do not pull your foot toward your buttocks because that stretches knee ligaments, which are not meant to stretch. Place your hands on your hips.