What can I do to improve my joints?

You can try adding potassium, calcium and vitamin d3 to your intake if you haven't already and if your diet and sunshine aren't providing enough. You could also consider glucosamine (some folks like it with chondroitin and MSN, but I just take glucosamine). Further, have a professional trainer or physical therapist spot you to be sure that you're using proper form and body mechanics. And, try a session or two of massage, either Swedish or sports) by a very competent practitioner, and they might be able to help with any tissue issues.