I am sold on the combination of yoga and weightlifting. Before I started practicing yoga regularly I was constantly sore, to the point of always rubbing my legs and top of my back. Foam rolling was good but the results didn't last and I can't afford regular massages. It's been three months that I've been attending at least three yoga classes a week and the difference is wonderful. My legs are simply not stiff and sore anymore. Sometimes, in the yoga class the day after training with weights I feel inflexible, and foot cramps happen, but I let the body ease into the position without always trying to compete with myself in the last class or the person next to me, and invariably I am much more flexible and feel amazing by the end of the class.
At first it was like eating raw broccoli, detestable but you know its good for you. Now I'm hooked. If weightlifting is making you feel beat-up and older than you were before you started, I implore you to find a beginner or restorative yoga class before giving up on the weightroom.