I don't really subscribe to the gym-class "stretch for 10 minutes before exercising," I typically try to do a 30-45 minute session of focused, opposed full-body stretching (yoga) at least 3x weekly. I'm a multi -sport guy, and my job has some particular physical requirements, so I can stay more ready for whatever I get up to on a particular day.

As I hit my 40's, I definitely started to recognize the benefits of a progressive (interval) warm-up as well; especially when I'm transitioning from cycling to running, or when I'm starting to ramp up a training plan for an event.