...............if performed BEFORE warmup exercises instead of after. I originally posted this in the Andre Johnson hammy injury: Early reports say "not serious" thread. After speaking to Infrantrycak, I thought I needed to post this to clarify my concerns on the injury front. Stretching before exercise can lead to less flexibility, tighter muscles, and injury. Yes, stretching is important. However, it is only useful and necessary when performed after a work out or activity. Ask yourself, what is the purpose of a warm up? Simple right, to warm up our body and prepare our muscles for the action to come. Well, stretching does not warm up our muscles! And ironically, stretching cold muscles can cause rather than prevent an injury. When our muscles are cold, or in their natural state, they are rigid. This inflexibility makes them sensitive to any strains or changes in length, and therefore susceptible to over-extension. However, once our body temperature is up and blood flows to our muscles, they are ready to take advantage of the benefits of a relaxing, cool down stretch. Think of a raw piece of spaghetti; if you were to bend it, it would snap in half. But, once you “warm it up,” it will bend any way desired.