Don't Flex in Vain
We've all seen the research suggesting that stretching before exercise doesn't prevent injury and may actually promote it. So why bother stretching at all? Because done correctly—after exercising or at least after a warm-up run—it increases stride, improves muscle elasticity, and, yes, reduces the risk of injury. Try to do it daily. But if you stretch cold, you're on your own. Approximate time: 10 minutes.
10 reps for each leg: