There are times when I can go out, do a good 5 minute warm up usually consisting of dynamic stretching, and play very well from the start of a match. My legs will feel good, there's relatively little or no pain, and my movement and footwork feel fluid and effortless. But lately, I've been noticing that more and more, I'll still be tight, and my legs feel like they're made of stone and I can't get out of my own way. This has been happening despite trying longer warm ups and stretching. But the thing is, I'll be bouncing around in between points to try to get the blood flowing and about half way into the second set, I'll finally loosen up, my movement becomes much better, and my entire game picks up. I've begun to notice this because I've come back several times recently from being down a set and a break. I need to figure out some way to warm up my legs quicker so I don't continue to put myself in situations like that.