I grew up an athlete competing at very high levels in a couple of sports but these past few years with life getting in the way I've primarily focused on the gym and cardio to keep me in shape. I got out and played some tennis this weekend and it hit me for the first time how stiff I've become, my back is killing me, my elbows a mess and I was moving terribly on the court. I need to work on getting that flexibility back, no way I could jump into something like yoga yet so any books or youtube vid recommendations on stretches routines I could start with to start getting me moving like an athlete again.